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Indoor Free Flight Forum => General Discussion => Topic started by: Olbill on April 08, 2010, 12:39:46 PM



Title: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on April 08, 2010, 12:39:46 PM
Feel free to add to this section whatever seems applicable. All of these topics are greatly influenced by personal preferences.

To get started here's my winding setup. The winder is from Geauga (Wayne Johnson) and has become unobtanium like the Wilder before it. A2Z has a new indoor winder on the market for $225 with dual output shafts for 10:1 or 20:1 and a counter. I haven't seen one yet. The much less expensive route is get a yellow winder from A2Z for about $21 and a winder brake kit from Dennis Tyson for another $15. You can see the brake kit at http://indoornews.com/.

The torque meter is one of two that I have used for a number of years. The one shown has a full scale capacity of 1.2 in-oz while the other goes to .6 in-oz. I have a set of construction pics that I will post.

The counter on my winder is made from a pedometer with a reed switch triggering the pedometer and a magnet on the winding handle triggering the reed switch. A problem (and benefit) of this setup is that if you wind fast it will skip. Winding fast is a bad idea which is where the benefit part comes in.

Most people use a more portable winding stooge that can be clamped to any available table. I drive to most contests so taking my table along is not a problem.

Some F1D fliers mount their stooge to the top of their toolbox so that they can wind and transfer the motor to the model at the spot where they will launch. A fully wound F1D is like a bomb ready to go off. Anything that can be done to lessen the possibility of damaging the model while preparing to launch is a good thing.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: DaddyO on April 08, 2010, 01:00:34 PM
Useful topic Olbill :)

Indoors I use a small wooden jig as shown.
Ali tubes in various positions allow for a range of models from the pistachio WeeBee as shown up to Bostonians. (I use a wire in tube set up at the back same as the outdoor jobs, just smaller. Although you can't see it very well there is a small lip on the back edge that hooks over the table and the clamp (which is a spare part from an angle poise type lamp), slides into a groove and is tightened with a wing nut under the table.

The plastic coated cup hook on the side allows motors to be wound for Easy B's etc which can then be transfered to the airframe.

Outdoors, strangely enough I was just re-making my jig and will post pics when it's finished...

Paul


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on April 08, 2010, 01:52:41 PM
Making a rubber motor

Most indoor duration fliers use two o-rings on their motors. The purpose of the o-rings is to allow a wound motor to be transferred from the stooge to the model safely and without losing any turns. A lot of different types of o-rings can be used. I cut mine from three different materials:

3/32” hard nylon pressure tubing (LPP and PP)
1/8” hard nylon pressure tubing and (F1L)
plastic imitation Q-tip shafts (EZB)

Here are my steps for making a motor to a specific finished weight:

1.Strip the rubber to the desired weight per unit length
2.Cut the strip to a little over the length needed
3.Lube with your choice of lube (silicone shock oil is my current choice)
4.Put 2 o-rings on the strip and put the strip on the scale
5.Cut pieces off of the strip until reaching the exact target weight
6.Grab the two ends of the rubber and tie an overhand knot as close to the end as you can get it. Pull the knot up tight. (first picture)
7.Grab the two strands of the motor – one in each hand – close to the knot and inside of the knot. Carefully pull the strands apart to move the knot as far as possible to the ends of the rubber. (second picture) If the knot comes out you've gone too far.
8.Tie another overhand knot inside of the first one and pull tight. (third picture)
9.Repeat step 7 to pull the second knot tight against the first one. (fourth picture)

Some people worry about damaging the rubber with this technique but I have not had a problem with it. The best part (other than it being easy) is that if you cut the lubed rubber with 2 o-rings to 1.495 grams, the finished motor will be 1.495 grams.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Rewinged on April 08, 2010, 02:36:24 PM
This was very timely for me. Thanks!

--Bill


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on April 08, 2010, 05:05:11 PM
Torque meter build

This is a very easily made, very accurate torque meter. The bearing is made from 1/8" and 3/16" pop rivets. I remove the center rods and then drill out the 3/16" rivet body so that the 1/8" rivet body will slide in with a fairly loose fit (no binding). (first picture - notice the excellent machining)

For the motor hook I use a short length of 1/16" brass tubing over the torque wire. This is for reinforcement and to keep the torque wire from getting bent where it goes into the large tube. (second picture)

The motor hook is bent from the 1/16" brass tube with the torque wire inside. The 90 degree bend is there to anchor the wire so it won't come out. With a fairly sturdy torque wire this eliminates the need to solder the tube to the wire. (third picture)

The pointer wire is wrapped around the 1/16" tube and soldered. Note that this is done far enough forward so that the 1/16" tube can go into the pop rivet bearing. (fourth picture)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on April 08, 2010, 05:17:03 PM
Funny you mention this Bill!

I saw this series of photos last night on the Indoor construction site and copied them to my hard drive. I was preparing a few questions when i saw this. Very timely indeed! ;D

I assume that the length and diameter of the torque wire is sized using one of the handy programs available on one of the indoor sites to suit the maximum torque required?

I have some thin-walled 1/32" diameter brass tubing that I was thinking of using for an A-6 suitable torque meter (0-0.5 in/oz??).

Do you think a Peck nylon bearing could be substituted for the aluminum pop rivets?

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on April 08, 2010, 05:23:59 PM
Torque meter build
Part 2

The first picture shows the finished hook and pointer assembly mounted in the end of a 1/4" brass tube.

The second picture is the rear anchorage for the torque wire. I think that the tube length I needed for this meter was longer than the tube I had so it was extended by soldering on an extra piece. Make sure that the wire loop at the rear is secure enough to not come loose. It's a good idea to do a strenuous load test of this connection to make sure you don't get hit by the innards of the meter with a motor at full stretch.

I solder the rear 1/16" brass tube into the notch in the outer tube. It's possible to make a rear connection that will allow you to release the tension in the meter when you're ready to remove the wound motor. I don't feel I need this feature.

The third picture shows the assembled meter ready for a mount and a dial face, and the fourth shows a finished meter.

The last picture is the front of my lower capacity meter. The 1/16" tubing is too large for some of the smaller o-rings that I use and the wire is too small for a hook to be strong enough. The solution was to double the end of the wire and run the doubled part back into the 1/16" tube that fits in the bearing.

I've been using the 2 meters I built with this method for the last 5 years with no problems.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on April 08, 2010, 05:48:02 PM
Tony

You can substitute anything you want for any part of this meter! This is just a case of me using what I had handy at the time and trying to solve some problems with previous meters.

The important points are these:

A loose front bearing. A ball bearing is overkill. The needles on my meters vibrate the whole time I'm winding. If the needle isn't vibrating then you've got a problem.

A strong motor hook that won't straighten out.

Reinforcement where the torque wire goes into the bearing. Without this the torque wire will get repeatedly bent at this point and eventually break.

A foolproof, unbreakable rear connection.

I like long meters with big dials because I can have small graduations on my dial and get really accurate readings. On my smaller meter I can interpolate readings into the thousandths of an inch-ounce. The longer wire also gets less stress at full scale readings and is less likely to develop a permanent deformation.

Yes, I use the online wire size calculators but I also test a finished meter and design a dial face that reflects the test values instead of the theoretical values.

Which brings up my last rant for right now which is about commercial meters and arbitrary dial face markings. If you're going to use the same meter for your whole life, and you never feel the need to compare your flying results or your winding technique with anyone else, then it's perfectly okay to have a meter that goes from 0 to 10 (or whatever) with no indication of what the units mean. But if someone tells me that they wind to 3.5 on a Johnboy #2 meter then I have no idea what that means. If I were to have a Johnboy #2 meter and if I were lucky enough that it was made exactly like the other person's then 3.5 might mean something.

But if another flier tells me that they launched their F1L on .17 in-oz of torque then I know exactly what they're talking about.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on April 09, 2010, 12:23:37 AM
Bill, thanks again for posting this. Your points are well taken.

I agree, it is useful to know that your torque meter is calibrated to a known standard so that you can talk intelligently with others. Been through a similar deal with F1B and torque meters.

One question for you on your meter shown in the photos. How is the "U" channel mounting bracket attached to the brass main tube? I assume that it pivots?

Do you plot your own dial faces on AutoCAD?

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on April 09, 2010, 12:36:01 AM
One question for you on your meter shown in the photos. How is the "U" channel mounting bracket attached to the brass main tube? I assume that it pivots?

Do you plot your own dial faces on AutoCAD?

Tony

The horizontal piece of the mount is a threaded brass rod that goes through the large tube a little off center. It probably touches the torque wire inside but I don't think that matters. One of my meters pivots freely up and down and the other has a mount I can tighten to hold it in a desired orientation.

Yes I do dial faces in AutoCAD. I will draw one for anyone that needs one or you can use the dial face drawing utility at indoornews.com.

And that was 3 questions!


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on April 09, 2010, 12:51:50 AM
Are you charging per question now? ;D ;D :D ;)

Tony
-I should soon be broke if you are!


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Pit on April 09, 2010, 08:31:43 AM
For an ignoramus in the usage of a torque meter, could you show a relative close-up of one in use (outdoor and indoor usage, bitte)?


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on April 09, 2010, 12:17:05 PM
Pete

This would probably take a video which I'm not set up to do. I'll do a description of winding a motor and maybe that will help.

BTW - I've never flown outdoor rubber so someone else will have to handle that part.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on April 09, 2010, 12:25:43 PM
Pete,

I can show an outdoor torque meter and how it's used, but it will have to wait a bit as I am moving back to the Toronto area this weekend and will have everything packed up for a while until I'm settled in. Starting a new job and all that.

The use of a torque meter outdoors is similar to indoor practice, but with some differences. For example, in indoor (duration) it is common to wind to near maximum turns, and then back off turns until a desired torque (not turns) is reached. This is not the practice with outdoor duration models. Typically, we wind to near maximum turns AND torque.

For fixed surface outdoor duration models (no auto-surfaces) I have a specific torque target that I will wind to. The model is trimmed to that torque so I don't like to exceed that value or the model might not behave itself.

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on April 09, 2010, 01:06:39 PM
Winding a motor for indoor duration flying

Disclaimer: This and all else I've written in this topic reflects my personal methods. Every indoor flier will probably have their own way of doing things that may be radically different from what I do. Also, this is written for someone who has never flown indoor duration models or who has very little experience.

Hookup
The knot end of the motor goes on the torque meter; the other end on the winder. For most right handed fliers the winding setup will be on the left side of the work table, and the model will be held in the left hand when transferring the motor to the model. Having the winding setup on the left side of the table will keep the model in a clear area off of the table while you're hooking up the motor. Figure out in advance what the approximate maximum number of turns and maximum torque are for the motor you're using.

Winding
1. Stretch the motor until the length from the torque meter to the winder is about 5 to 6 times the resting length.

2. Begin winding at a fairly slow pace. While the motor is stretched to this length you will want to put in around 50% of the total number of turns that the motor will take.

3. Test the motor at frequent intervals when you are getting close to the 50% mark. Test by grabbing the motor a foot or so in front of the winder and pull on it towards the winder. When the motor starts feeling hard instead of stretchy it's time to move in towards the the torque meter. All rubber motors will have this point where they feel “hard” instead of “stretchy”. It may take a little practice to be able to recognize the difference.

4. Move towards the torque meter a foot or so and continue to wind at a slow pace. Put in another 100 to 200 turns and test the motor again. When it starts to feel “hard” again it's time to move in some more.

5. Continue this process until you're either at the maximum torque you're aiming for or the motor breaks. As you get close to maximum torque you should test the motor frequently. When you are close to the maximum torque that the motor will take the torque will climb a little as you wind and then fall off a little when you stop. Near the breaking point the drop off happens faster. At this point putting in more turns is likely to break the motor. When you reach your target torque the motor length should be about the same as the hook to hook distance on your model.

6. Record your torque and turn numbers and then back off turns until you reach your desired launch torque.

7. Lock the winder and place it in its holder on the winding stooge.

8. Pick up the model and hold it at the prop hub so that the prop can't turn.

9. Position the model over the wound motor with the prop end over the winder.

10. Grab the wound motor by the o-ring so that the front of the o-ring is exposed. Take the motor off of the winder, being careful to not let the o-ring slip back between your fingers. Hook the o-ring onto the prop hook and release the o-ring gently to let the motor torque transfer into the prop shaft.

11. Hold the model (still by the front bearing area) over the wound motor and grab and remove the rear o-ring from the torque meter.

12. At this point you can hook the motor onto the rear hook of the model or you can continue holding the rear o-ring in your hand while you move to your launch point. Some models will take an undesirable semi-permanent warp from the wound motor, so the less time it's on the model the better. In either case, after making the rear hookup release the rear o-ring gently to let the motor stick take the torque. Avoid shock loads as much as possible.

13. Launch and admire your excellent work as your model slowly works its way to the ceiling!


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Hepcat on April 09, 2010, 05:19:17 PM
A very well done tutorial Bill, I keep finding myself saying ‘Yes’ to the points you make. One example is the double overhand knot for tying rubber. I only came across this two or three years ago (and thought it sounded crude!) but once I had tried it I was a convert to its use, particularly for indoor motors.

It may not be apparent to some newcomers why the Cezar Banks type of torque meter is gimbal mounted. With a fixed torque meter, if you inadvertently (or intentionally) move sideways or move the winder up or down then the rubber puts a side load on the torque meter front bearing which will usually cause errors in the torque reading. The gimbal mounting avoids this trouble.

I attach some pictures of my attempt at a Banks type meter. Tony, Mat has mentioned recently on the Outdoor Stooge thread that UK modelers like to make things out of old fence posts and at a cost of no more than 3 pence. I should point out that the 3p should include labour costs and any sales tax. On my meter I think that I have stayed pretty well within the guidelines. The main wooden parts are cut from an obeechi fence post and the vertical are thin plywood. Brass tube bearings hold the hook and pointer at one end and tail wire at the other. The required length of torque wire is calculated and the wire is cut a little longer than this. The wire is then tested with a weighted torque arm and the length is reduced to give the correct torque at full scale deflection. Like Bill I cannot stand uncalibrated torque meters.

There is a piece of wire which runs from a knob in front of the dial through some short paper tubes taped to the bottom of the main body. The rear of the wire is formed as in photograph 3 and the end of the wire enters a hole drilled in the main body. The green is a piece of litho plate wrapped around the wire. In use the knob is pulled forwards so that the litho plate is in contact with the rear of the main body and the tail wire is prevented from rotating because the turned over end of the tail wire is blocked by the litho plate. However if the knob is pushed in, as it is in photograph 3, the tail wire can rotate in the gap between the litho plate and the main body.

A release such as this has been mentioned in Alan Cohen’s ‘Minislick’ thread as useful for completely unwinding a motor. I find I use it much more for getting the motor off the hook of the torque meter. You are holding the model and the propeller in you left hand and you need to take the rubber off the torque meter hook and transfer it to the model. It can be difficult, the ‘o’ ring can be tight on the hook, the hook can turn and if the torque meter is gimballed it can swing anywhere! It is possible to pinch the motor just away from the ‘o’ ring, press the button with another finger which will release those few turns needed to free the motor from the hook.

John


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on April 09, 2010, 05:39:59 PM
Very good John, well within the UK cost limit that I suggested. ;) I forgot to mention the other key material that most UK modelers are well acquainted with, "bent wire and brass tubing". Naturally, the word "brass" is pronounced as "brahhss" to get the full effect. ;D

I'm warming to the torque release lever contraption. I would like to hear Bill's comment on this and why he does not use one on his torque meters?

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on April 09, 2010, 07:51:09 PM
I'm warming to the torque release lever contraption.

I would like to hear Bill's comment on this and why he does not use one on his torque meters?

Laziness maybe?

I just don't usually have a problem with getting the motor off the rear hook. And I shudder at the prospect of unwinding a motor by hitting the release on the meter. That sounds like an only partially controlled explosion.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on April 09, 2010, 08:56:19 PM
And I shudder at the prospect of unwinding a motor by hitting the release on the meter. That sounds like an only partially controlled explosion.

I wondered about that. But perhaps the inertia of all the metal bits slows down the motors unwinding at such low torque levels as used with indoor motors?

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on April 09, 2010, 09:39:51 PM
I wouldn't do it with any motor. It's always best to actually unwind the motor. That said, I will sometimes let go of the winder handle if I'm in a rush or just getting tired.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Pit on April 10, 2010, 06:19:39 AM
Guys,

Thanks a bunch for the info. It's helped clear up some questions that have been beating the backsides of my eyeballs. I realize that the meters for outdoor models are on the winder end, so I was curious just how it was done for the small, delicate models. I would have gotten "hands on" info had I made it to the IIFI.

I still have to bookmark the site where the wire sizing chart is if I get around to making a meter.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on April 10, 2010, 08:39:09 AM
Pete,

There have been some modelers that use a stooge mounted torque meter for outdoor rubber powered models. Bob White used to use one (made by Bob Wilder if I'm not mistaken) as did Walt Ghio (although I don't think he does currently). The big drawback for the stooge mounted outdoor torque meter (in the past) was that, with the model mounted in the stooge (with or without blast tube) any breeze present would rock the wings and affect the torque reading accuracy. Walt tried to combat this by removing the wings from the model during winding.

With F1B, we now wind our rubber motors outside of the model (just like indoor) using a partial, rigid winding tube that allows for an easy transfer of the wound rubber motor to the model. A 1/2 turn bayonet fitting is used on a rear bobbin so that a quick insertion of the semi-tube and a twist of the wrist is all that's required to install the motor. No rear peg or pin is removed or replaced for the installation. (although the standard rear peg is still in place. It just never comes out of the model now).

The point is that with the new winding system, a stooge mounted torque meter has become quite feasible again for outdoor rubber models. The main problem with the winder mounted torque meter is that the torque meters spins around and the winder has to be stopped to take a torque reading. With the stooge mounted system you can just keep winding and actually watch the torque build up progress while you are winding.

I'm seriously thinking about a stooge mounted torque meter for my F1B models.

See the attached photo for details of the 1/2 tube winding method. It's a photo of Alex Andriukov winding btw.

Incidentally, the winder is now equipped with "Blast Shield" to protect the flyers hands.

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Pit on April 10, 2010, 04:11:33 PM
Thanks Tony,

I spent the better part of last evening going over Anriukov's site, so I was able to get an idea about the what's and how's ;D. The exploded view for the hub was a real eye opener - I see now WHY they are not inexpensive. Real engineering marvels.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on April 10, 2010, 05:14:10 PM
Incidentally, I'm making a set-up to wind my P-30's using a mini half tube as I have found that once I tried winding outside of the model, I cannot imagine ever doing it the old way ever again!

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: DerekMc on April 10, 2010, 05:38:40 PM
Incidentally, I'm making a set-up to wind my P-30's using a mini half tube as I have found that once I tried winding outside of the model, I cannot imagine ever doing it the old way ever again!

Same here!


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on April 19, 2010, 03:07:38 PM
Motor with Sleeves

Here's my method of making up a motor with sleeves. Sleeves are a good idea on long motors for LPP, PP, A6 and maybe others. They will help prevent knots from bunching up at the rear hook - causing a CG shift - or at the front hook - causing the prop to stop.

My sleeves are made form heat shrink tubing. The tubing I had on hand was a little larger than I wanted so I shrunk it in short sections on a piece of 1/8" aluminum tubing and then cut it up into approximately 1/4" lengths.

I like to use the rear knot to hold the rear sleeve tight against the rear hook. It's difficult to do any manipulation of the rear sleeve after the wound motor is attached to the model, so a way to automatically position the rear sleeve is helpful.

Step 1 - For both ends of the motor, thread the end through the sleeve, through the o-ring, and back through the sleeve. (first picture)
Step 2 - Tie the loose ends of the motor. (second picture) (see earlier post for knot)
Step 3 - Pull the knot against the rear sleeve and o-ring and pull the front sleeve against the front o-ring. (third picture)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: julio on April 19, 2010, 08:29:08 PM
Olbill

Thanks a lot for this topic. Plenty of useful information and pics. Great work! Very kind from you!

Julio


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on April 19, 2010, 09:50:24 PM
Very good advice on this thread. I took Olebill's knot in reply 2 to Sarasota last weekend and showed it to a couple of the guys. We had been trying to teach ourselves to tie that mountain climber's knot on the Indoor Duration site without losing 2 inches of rubber every time and Olebill's knot was welcomed. Not as tiny and elegant, but it ties quick and easy, loses no length, and it's plenty strong enough.

I made this contraption up this afternoon after one "proof-of-concept" model this morning. I took seriously what Hepcat wrote (I always take Hepcat seriously) in #15 about being able to quote actual numbers, and I had been mulling this around in my head for a couple of weeks. I just wound a Hangar Rat motor on it to its normal 1600 turns, and the machine registered .8200 oz/in when I locked the winder in. Then I just sat there mesmerized, watching it count down to about .7400 in less than a minute. There's a lesson there, but I'm not sure what it is. There's gotta be a way to do that on purpose and then take advantage of it.

My initial problem was transferring the motor from the device to the Parlor Mite without wrecking it. A couple more readings of Olebill #14 and I'll have a better shot at it.

A.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on April 19, 2010, 11:34:12 PM
Wow!

Art, that's brilliant! Can you give us some more details?

I can see that the bracket is metal (steel?) and the wire shaft is mounted in some type of bearing (both sides I presume) and I also assume that the distance from the center of the shaft to the end of the outrigger is exactly 1 inch in order to give a reading in in/oz?
Is there a thrust bearing on the back side?

It doesn't look like you are using an O-ring. If not, then an O-ring should help you get the motor off of the hook with less problems.

Very clever imo!

What's the scale read in. 0.001 oz?

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on April 20, 2010, 12:36:05 AM
Details... This is how I did it... you don't have to. The brackets are .062 aluminum, shaped so they clear the scale and the pivot holes are one inch to the left of the center of the tray and about 1/8" higher. The wire is all .031. The arm is one inch, as is the counterweight arm. From front to back, there's the hook, fwd bracket, a cheap ball thrust bearing, and a rubber tube spacer to make the thrust load go onto the bearing face rather than its hub. The wire arm is wrapped twice around a short piece of 1/16 brass tube and the whole thing is soldered on (that's the first operation... the spacers go on after). Behind that is a loose fit piece of gold-n-rod to prevent the whole ass'y from being pushed back as you remove the rubber from the hook. The holes in the brackets are 1/16.

The pic is of the first test motor; from now on everything will have 2 o-rings.

This pic is of the first one, showing the winder holder, which is probably wrong. Somebody will have to tell me how to do it right. Maybe lock the winder handle rather than the hook, so that end of the motor is more easily handled. Those big bearing blocks had a slight bind in them... the current ones don't. The arm was 2.835" long, and I was reading off the gram scale and dividing by 10 to get oz/ins. Stupid. The reason for the dog leg in the new brackets is so the shorter 1" arm hits the tray right in the middle. The ounce scale reads to 4 decimals.

Other scales may present other, or fewer, problems.

A.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on April 20, 2010, 02:17:43 AM
That is extremely clever! One meter does it all and to an accuracy level we never dreamed of.

A normal torque meter doesn't have to have a fancy bearing because the torque wire takes all the thrust. I would guess on this rig you have to have a pretty good thrust bearing to keep the scale reading from lagging behind the actual torque. How well does your ball thrust bearing work for this?

As far as the reading falling while the motor is wound this can be a problem on a VP equipped model but not so much on a model with a fixed pitch prop in low ceilings. When you back off a bunch of turns to keep your model off the ceiling the motor will hold the lower torque for a long time.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on April 20, 2010, 02:30:09 AM
For a way to lock your winder go to the home page of indoornews.com and look at the lock that Dennis and Parker Tyson are selling for the yellow winders.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on April 20, 2010, 07:20:24 AM
Thanks for the info Art. I'll have to ponder this for sure.

I've attached a picture of Dennis' winder brake and his method of attaching it to the base. If you look on Alan Cohen's mini-stick thread you will see a slightly different solution. You need a way to adjust the length of the torque meter hook to winder hook length so that it matches your model's propellor hook to rear hook length. You might have several different models with different rubber lengths.

The shaft arrangement with a thrust bearing is similar to a P-30 front end. I've bought several small ball thrust races and have not been satisfied that they are less friction than a couple of good teflon washers.

I bought one of Dennis's winder brakes and it's a good investment imo and supports a good cause.

Here is the link: http://www.indoornews.com/

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Mooney on April 20, 2010, 07:37:10 AM
Can someone post a link or photo of the setup for winding outside the model? For ex, the portion of the motor that hooks to the peg?

Thanks


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on April 20, 2010, 08:45:14 AM
The shaft arrangement with a thrust bearing is similar to a P-30 front end. I've bought several small ball thrust races and have not been satisfied that they are less friction than a couple of good teflon washers.

I think that even the ball thrust bearing is overkill, considering that there's zero rotary motion of the shaft. All it does is transfer pressure. No bearings, bushings or gimbals required. The vibrating needle Bill likes to see as he winds is is displayed on this rig as the scale reading bouncing up and down thru a pretty good range.

I have some ideas about a sliding mount for the winder...I'll see what's floating around the shop to make something out of.

Thanks for the encouragement.

a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on April 20, 2010, 08:53:49 AM
Can someone post a link or photo of the setup for winding outside the model? For ex, the portion of the motor that hooks to the peg?
Thanks

Indoor or outdoor Mooney?

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on April 20, 2010, 10:57:17 AM
Fixed it. Drilled a line of 5/64 holes 1/2" apart from the winder hook 6" back towards the scale hook. A 2" length of pushrod wire flattened a little at the bottom so it stays in the hole, and dressed smooth at the top so it doesn't cut the rubber, holds the winder end nicely and simplifies removal and transfer to the aircraft. I tried it on a Phantom Flash because they're more damage resistant than Parlor Mites, although hanging the wound motor on the front hook is more of a challenge. I've been practicing with the Parlor Mites and the Minislick, too, and I think I'm beginning to master the technique.

I had the foresight last week to salvage the hose from a Waterpik that was tossed. .09 ID, .15 OD, 3 feet long. That's almost 300 o-rings! And bright white, too, so you can see them in dimly lit gyms.

Now I have to make an adapter to wind the Polly, the Pussycats, and other models with fuselages and rear pegs. No big deal, I don't think.

a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on April 20, 2010, 01:14:03 PM
Art

For years I used salvaged tubing from pump sprayers and any other unsuspecting source I ran across. This is fine as long as your o-rings meet one major criteria - they can't twist under maximum torque. The nylon pressure tubing that I've been using for several years now holds up well as long as you don't make the rings too thin. For my F1L motors wound to around .5 in-oz a too thin ring from 1/8" tubing will wind up with the motor and it stays that way permanently. Once this happens it's very difficult to make the motor hookup on the model.

On my F1M motors that go to about .8 in-oz I've started using the 3/16" tubing just to avoid this problem. At Lakehurst last year my last flight was just before dark. It was my last good motor with a wind that got to the target torque without breaking and the last possible flight due to the disappearing daylight. The combination of low light, fatigue and bad eyes was enough of a challenge without having to deal with a collapsed o-ring.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Hepcat on April 20, 2010, 04:10:17 PM
Art

Brilliant. I suspect that you have changed the style of indoor torque meters for many years to come.

John


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: olddog on April 20, 2010, 05:28:28 PM
Hi Gang: I used to use "O" rings from bic lighters that a friend collected for me. I had another source from a hobby shop that specialized in electric R/C cars. Haven't flown indoor for a while, but still have a bunch that I'm saving for future use.

Ron (Old Dog)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on April 20, 2010, 06:40:54 PM
John... this evolved from your reply #15, which got me thinking about how I could calibrate a couple of my homemade tube/musicwire/disc type meters using the gram scale as a reference. Once I got this far I realized that I could wind right to the calibration apparatus and discard the old-fashioned meters.

Ron... Dave Andreski had suggested that there was a treasure trove of discarded Bic lighters in the gutters. Just pick 'em up and strip the parts out. But he lives in the Conch Republic, where smoking is just one of the more benign of what we might call "negative behaviors". I rarely see lighters in the streets around here.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on April 21, 2010, 08:45:16 PM
Art,
How are you finding your gram scale as pictured? With some gram scales I have tried for other applications, they stop after a slight pause in the weighing and show the weight at that point. This wouldn't work for the torque meter application.

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on April 22, 2010, 09:45:08 AM
It's a Digi-weigh, a $10 (+$6 s&h, even though the postage was only $2.54)) e-bay "buy it now" job. No damping at all... just blow on it and the numbers change. It's possible that the seller can tell you if it's undamped if you ask them.

a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on April 22, 2010, 10:53:23 AM
Here's a link to over a hundred different pocket scales:

http://www.scales-n-tools.com/index.php?main_page=index&cPath=5&zenid=v38q7gghobmucj58qmksnts1c3

Art, why the counterbalance on your rig? Wouldn't zeroing the scale take out the effect of the arm weight?

I'm working on a design that does away with the rear bearing and also puts a little bit of pre-load on the scale. After I get back from Kent I'll try to cobble one up and see if it works.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on April 22, 2010, 11:23:32 AM
Bill, why would you need a pre-load?

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on April 22, 2010, 11:47:15 AM
Why the counterbalance on your rig?

Why not?

EDIT: Sorry, that was a kinda snotty rejoinder. Actually, as I'm not an engineer and not totally familiar with the forces involved, I just figured it couldn't hurt. a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: BG on April 22, 2010, 12:22:17 PM
Hi All,

I am very impressed with this pocket scale torque meter idea! very clever!!

So how do you read the scale readout as you wind though? Or do you just wait till you get all the way back to the stooge? I ask because it might be fun to try this on an outdoor stooge but I need a way to see the readout easily.

B


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on April 22, 2010, 01:48:29 PM
Tony

Pre-load just to keep everything from flopping around and to set a reliable zero point. Understand I haven't tried this yet.

Bernard, this bothered me for awhile but actually when I'm winding I don't really use the torque meter until I'm almost all the way back to the table. This is another thing that needs to be explored. I looked at hundreds of different scales to see what was available with LARGE readouts. Not much.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on April 22, 2010, 02:26:57 PM
Bernard...

I thought of that at the beginning and figured that I'd just place the scale vertical. This scale wouldn't work vertical (others might, though).

So I just ran some measurements, which are valid for my setup. The scale tray is about 38" above the floor, and my eyes are 24" above that. I can see the readings clearly from about 30-36" away from the hook. I think that for indoor work, where we have either 30" high bridge tables, or similar picnic tables, you're covered.

Outdoor, wind-'em-til-they-bleed genre isn't my field... I'll defer to Bill on that.

a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on April 22, 2010, 04:57:50 PM
You might also be able to use a simple mirror to let you see the scale for the indoor winder. Outdoor has some other issues.

To get accurate torque readings on an outdoor meter, you need to wind the motor outside of the model using a 1/2 tube (or similar) type of arrangement like we do in F1B. If you want to try it while winding a motor in an airplane, you have to remove the wings (wind gusts act like a torque arm and change the reading). Even a large stab might cause an issue. Winding the motor itself solves that problem.

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on April 26, 2010, 02:19:58 PM
Jeff Hood photos from Kent. Many excellent shots with a number of different winder setups.

http://picasaweb.google.com/jeffrey.hood/Kent2010#


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on May 19, 2010, 01:28:29 AM
I brought the torque meter to the session at Rockledge on the 15th and it was well received by my friends there. I got orders for 2. The first one ships tom'w, and the second is waiting on scale dimensions to come in.

They take about an hour to make from shop scraps. Mine are aluminum because that's what's here, but I can imagine a very elegant one in 1/16 ply.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on May 19, 2010, 02:16:30 PM
Art, I bought the exact same model scale that you have from Deal Extreme (cost me $13.00 incl shipping!!). I'm going to try and have at go at making one myself using 1/32" music wire and two Peck nylon bearings (with 1/32" hole). I've made a little center collar from brass rod with a 1/32" hole and another 1/32" hole at 90 degrees (to mount the cross wire). I'll drill and tap it for a 0x80 set screw like a mini wheel collar.

Did you see Ray Harlan's critique on the Indoor Construction group? Basically, he felt that the drawback to this type of torque meter was that there will be some friction at the front bearing because the shaft will be loaded in tension (compression load on the bearing). The thought was that this friction would be greater than that encountered from a conventional torque meter that has the torque wire secured at the back end so that the front bearing only sees a rotational friction force, not a compression load.

A good point, but I'd like to see for myself how it works, plus it looks fairly easy to do.

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on May 19, 2010, 05:08:53 PM
Art, I bought the exact same model scale that you have from Deal Extreme (cost me $13.00 incl shipping!!). I'm going to try and have at go at making one myself using 1/32" music wire and two Peck nylon bearings (with 1/32" hole). I've made a little center collar from brass rod with a 1/32" hole and another 1/32" hole at 90 degrees (to mount the cross wire). I'll drill and tap it for a 0x80 set screw like a mini wheel collar.

Did you see Ray Harlan's critique on the Indoor Construction group? Basically, he felt that the drawback to this type of torque meter was that there will be some friction at the front bearing because the shaft will be loaded in tension (compression load on the bearing). The thought was that this friction would be greater than that encountered from a conventional torque meter that has the torque wire secured at the back end so that the front bearing only sees a rotational friction force, not a compression load.

A good point, but I'd like to see for myself how it works, plus it looks fairly easy to do.

Tony

Art and Tony:

The design that I was thinking of would nearly eliminate any friction at the bearings. Basically the rear attachment would be a wire fixed to the rear support. There could be a slight preload by winding up the wire a little and then zeroing the scale. There actually is no (or very little) rotation of the torque member in the front bearing because there is very little actual movement of the weighing pan. If there is no rotation then there would be no friction.

Where the wire is attached to the rear support there would be close to zero movement of the wire.

I've done a real crude hand held mockup and it seems to work fine. Here's an equally crude drawing.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on May 19, 2010, 06:01:35 PM
Interesting idea Bill. I think that's worth a try. What sort of wire diameter were you thinking of using for the torque wire?

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on May 19, 2010, 10:07:02 PM
It makes no difference what you use for a thrust bearing (the ball type I used is way overkill) because experience shows that the torque force is a huge multiple of the the tension.

The third and fourth ones have Tefzel thrust bearings and they're fine...the scale reading bounces around as you wind, and as soon as you stop, the torque reading starts to decrease instantly. If the rocker was binding on the frame (or on anything) the reading would hold and then there would be a sudden release.

I made up a noose of fine nylon thread and wrapped one end around the rear frame at the shaft and the other end around the arm at the front, then pulled it tight till it released the thrust bearing from contact with the front frame. Now we had Zero friction. The behavior of the winding and relaxing motor was exactly the same as before.

All due respect to Mr. Harlan, but it's a non-issue. You guys are complicating a simple, effective and easy to build device to accomplish nothing.

As a couple of more get built and used, you'll see that.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on May 19, 2010, 11:24:25 PM
Interesting idea Bill. I think that's worth a try. What sort of wire diameter were you thinking of using for the torque wire?

I dunno. Maybe start with something around .020 inside a 1/16 tube and see what happens. I could probably put one together in less time than it took to do the drawing.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on May 19, 2010, 11:58:33 PM
What will happen is that you'll get a reading lower than the actual torque.

a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on May 20, 2010, 12:01:34 AM
What will happen is that you'll get a reading lower than the actual torque.

Why do you say that Art?

I'm not trying to complicate it, just passing on the comments I've read elsewhere. I think it's a great idea too.

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on May 20, 2010, 12:41:44 AM
Because what Bill is building here is basically a common torque meter without the disc. The .020 wire will resist the twist and lessen the force of the arm on the tray. That was my immediate reaction.

But, now that I think on it more, he's not wrong, I am, because there's no measurable rotation of the shaft...it just changes twisting pressure to linear downward pressure without actually moving.

I think #5 will be a variation on his theme. I sort of like it.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on May 20, 2010, 12:24:55 PM
Good Olbill. Here's #2 modified into #5. 1/16 brass tube and 20# Stren fishing line.
Solder the arm onto the tube and bend and/or trim it to length. Dress the hook end of the tube smooth, because you'll be pulling the motors off it. Slip the string in and tie a knot at the hook end. Leave a few inches at the anchor end. Bend the hook... I thought this step would capture the string but it didn't so I pulled out a half inch or so, spread it with CA and pulled it back in. That did it. Then cut the knot off. The fwd hole had to be opened to 5/64 so the bent tube would pass thru it. You can see how I clamped off the back end of the string. Just pulled it up snug and tightened the screw on it. A tiny gap opens up between the tube and frame when the rubber pulls on it.

Thrust bearing fears eliminated!

a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on May 20, 2010, 01:52:23 PM
That's pretty slick Art!


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on May 22, 2010, 07:56:20 AM
Ok, my first attempt for a digital torque meter. I took apart a 100g/0.01g cheapo scale. Unattached the torque element, built a new rig to hold it. Seen at the back. The body of the meter is a U-shaped piece of aluminum, just as in the ones that we have seen before. To that, the torque sensing element, at the back side of the aluminum body in the picture, is attached, with screws to the bottom on the left end. The side arm from the torque rod pushes the right end of the element down. So far no fancy bearing to the torque rod, and the side arm if from a D-connector. Need to make a better one, but this one was just to test the concept. Taking the scale apart enables me to make the thing more compact, and to turn the meter face more horizontal to make it readable from further away. I'll have to saw the scale body apart next, it will make a good housing for the electronics. Then I need to get a compact battery holder to replace the current, also using the scale part.

First attempt of winding rubber on the scale indicated that the readability is good, and the scale reading does not vary too much, so I think this works as good as analog one, if not better. And what is best, "one size fits all". This has enough sensitivity to work for LRS, while the force element can handle SO sized models.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on May 22, 2010, 09:49:16 AM
Tapio, this one's beyond both my ability and comprehension.

To return to the thrust bearing question, I've been testing a couple of units that I made for friends to the original design, but with Tefzel bearings instead of the ball bearing. The performance is identical on all styles and the one with the string isn't any better (you can't improve on perfect). My criterion is: How fast does the torque start to slack off after you stop winding? With all of them it's instantaneous.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on May 22, 2010, 12:01:32 PM
Ok, reworked the thing somewhat. Now the framework holding the circuit board is sawn apart, a small battery holder for the two AAA cells. But most of all, the part from D-connector is discarded, instead there is a full length of 1mm id 2mm O.D. brass tubing holding inside the 1mm wire for the hook. This makes the thrust bearing, sliding against a teflon washer inside the aluminum frame. Over the tubing is a shorter piece of 2mm/3mm tubing, making a snug fit for a 3mm wheel collar. the two tubes are cut through and there is a flat surface on the wire, so that the collar locking screw locks the setup from rotating on the wire even under torque. And now comes the neat part: the screw is over-length, and there is a thin washer between two nuts, pressing against the sensing element of the scale. Thus moving the washer, I can fine-tune the moment arm -> fine-tune the readings of the scale.

The setup seems to work smoothly, the reading run but not too fast to get the big picture of the torque. If I stop winding, the readings start to drop, as they should, and also the pull/release of the rubber stretch affects the readings.

Next task. Order a couple of extra scales for replacement parts... :-)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on May 22, 2010, 12:01:37 PM
Very cool Tapio!

I can't see from the picture how the wire shaft is restrained in the U-shaped bracket. Is there an arm or something that stops it from being pulled out and what pushes on the torque element? You mention a side arm but it's not clear. Is the readout from the original scale, or one you had on hand?

Modified after seeing the second posting from Tapio:
Umm, isn't the photo the same? ;D
Where's all the cool new doodads?
O.k., now I see it!
Even cooler! ;D
What's the scale read for you, cm/grams?

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on May 22, 2010, 12:07:02 PM
Yeah, goofed with file save, trying to recycle the file name.... But now the new pic is there, and we can forget about the temporary arm, that did not hold under TQ that good anyway....

I still need to think about a fancy attachment to the winding rod and keep the torque element, display and battery in one unit.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on May 22, 2010, 12:40:56 PM
Tapio
This is all very cool! I think your experiments are confirming what Art has seen in his meters - that the concept works.

Art
Yes it's normal for the torque to start dropping immediately when you stop winding. There's some disagreement about indoor winding technique but many believe that a very slow wind gives the best results. The rubber stretches as you wind it and a slow wind will allow the rubber to conform to do its stretching while the torque increases. Once the motor has stopped stretching it will hold the torque pretty reliably. Another factor calling for slow winding is heat buildup in the motor. When rubber gets warmer it contracts. This isn't a good thing when you're close to maximum turns and torque so letting the heat dissipate during winding is logical. Some F1D fliers are said to take 10 minutes to wind a motor.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on May 22, 2010, 01:40:20 PM
Let me tell you about my motivation and my general level of sophistication in this. My main flyers are a pretty good Hangar Rat, and two fair to middling Phantom Flashes, plus some Bill Brown and Dick Baxter fun flyers. The most sophisticated level I've reached is two parlor mites that fly beyond expectations and a 40% overweight Minislick. So I read and try to absorb the science of this but don't have much to apply it to as I've never flown under a ceiling higher than 26 feet. I'm just now trying to learn how to cut and wind rubber to maximize the times while not hitting the ceilings.

Motivation... I tend to be parsimonious. Everybody talks about torque being more important than turns, but I was happy with my 20-1 K&P winder until it turned out it was really 15-1 and I had to learn the 15 times table to be able to use it properly, or else spring for $220 plus frt for a proper one. I had made a couple of simple torque meters calibrated 10° apart and numbered 1,2,3, etc., and after reading Hepcat's opinion (he's like God to me) that we all need to work with the same units of measurement, I decided to try to make up a device to calibrate them properly. I felt this apparatus could and should be made from shop scraps and my $10 Communist Chinese 100 gram scale.

Somewhere during the process, the calibrator became the meter. No extra charge.

a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on May 26, 2010, 11:25:21 AM
I played with the last version (the one with the string) for awhile and decided that it was just dopey, not worth the effort. Here's the final one. The hook and arm is one piece and the tail is the other. The solder joint is 3/4" long and doesn't need binding as there's no real stress on it. The tubes are nylon (Nyrod and Goldenrod work fine, too). It's loose as a goose and about as simple as it can get.

An alternative is to double the arm back on itself and bend it into a tail, thus eliminating the soldering job. I did one like that of .020 wire just to try it out. It works, but flexes a bit, which I don't think affects the accuracy. It'd probably be better with .032.
 
Also, why does the hook need to be a real hook? Just bend the wire 10 or 20° past 90 and leave it about a half inch long. The rubber won't jump off it and it's much easier to unload.

a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on May 26, 2010, 12:24:56 PM
What's it look like installed Art?

What stops the wire from pulling out of the bracket?

Tony
-I should probably wait for the next picture, but inquiring minds.... ;D


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on May 26, 2010, 01:58:08 PM
The two nylon tubes act as spacers, locators and thrust bearing. The one piece rocker is kind of rickety, but if it were made of stouter stock, with a metal tube on the arm instead of plastic, it would be just as good as the soldered up one.

I tried to get readings on them both to see if they matched, but the rubber relaxed a bit while I was doing the R&R. The value of the drop was consistent with the time lag, though.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on May 26, 2010, 02:21:19 PM
I see now. So the distance from the center of the shaft wire to the end of the torque arm is 1.0"? That way you get automatic readings in in/oz.

Looks good!

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on May 26, 2010, 02:38:54 PM
I'm liking this more and more. As soon as USIC is over I've gotta have one.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on May 26, 2010, 03:16:25 PM
Here's a new gadget I picked up today for $50 from Office Depot. It's a folding aluminum hand truck. Since I still carry my models in cardboard boxes I extended the load platform at the bottom with a piece of thin plywood. The cutouts in the plywood are so the truck will still fold flat. Including the extension it weighs about 8 pounds.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: FLYACE1946 on May 26, 2010, 03:20:16 PM
Good idea for transporting model boxes. What size boxes do you use and where do you locate them?

Are the boxes new or used?


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on May 27, 2010, 07:55:51 AM
Since I rarely fly to contests I use any large boxes that I find. I put one or two completely assembled models in one box. I'm leaving for USIC in a few minutes and this is what I hope will go in the car. (see photo)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: FLYACE1946 on May 27, 2010, 11:01:25 AM
Thanks for the tip on recycling those big old boxes. I use 2 old vacuum cleaner boxes for storing and also traveling to fly.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on May 27, 2010, 02:09:42 PM
This one is in addition to the unit in the earlier photos. It's made for winding the motor on the model. The rocker is made to hold a 1/8"diameter hub, which most of my indoor planes have. The main feature is the brass piece that loosely holds the hub. I've eliminated the long board with the winder holder, so the model can hang loose. It has a diagonal cut thru into the hole in the fwd hanger (like in a prop hanger) so the rocker ass'y can be loaded.

The second is a simple adapter for models with fuselages which must be wound from the nose. The third shows it in use.

To change the subject, the last shot is my current box, an American Racing mag wheel box, 20 x 20 x11. Two cleats were glued in to stop the flaps, and diagonal dividers were added. Right now it carries two Pussycats, two Phantom Flashes and a Hangar Rat and there's room for more. The side compartments hold props, rags, motors, lube, whatever.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on June 13, 2010, 07:10:48 PM
Here's my first working electronic torque meter. It's actually my second try with mostly the same parts but the first one had too much friction in the bearings.

This one has an .020" wire inside a 3/32" brass tube. The wire has a 90 degree bend at the back bearing and is secured to the rear vertical plywood. When the wire is secured at the rear bearing it's located to give a small preload to the 1" arm as it rests on the load cell. The wire is doubled at the front to make a hook strong enough for PP size motors. The 3/32" tube has a very loose fit into larger brass tubes at both bearings.

After I've done some real world testing with the meter I plan to do a small production run. The next ones will have all the wiring concealed, the battery box on the inside of the rear support and the triangular openings on the sides will be filled with plywood pieces. All the plywood parts will be laser cut.

The friction problem on the first version showed up in backing off turns from a very light EZB sized motor. I found that a good, easy way to check for this problem is to turn the meter on, twist the hook to a low reading and then let it go. The LCD reading should go back to zero. In fact it should go back to zero from any amount of torque but low torques are what caused the problem in the first version.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on June 21, 2010, 05:34:18 PM
Here's the URL for a 20g x .001g scale for $15.23 including shipping. I ordered one today in hopes it will be good enough to take to contests instead of my plug-in Acculab. I'll post a report when I get it in my hands.

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=280392289572

The digital torque meter had some problems this weekend. The simple one was that the solder joint on the torque arm failed. The more major one is that I discovered that the centerline of the torque meter tube has to be the same distance above the table as the hook on your winder when the winder is docked. If the rubber motor is pulled out of line with the meter the torque readings will change. This is probably true to some extent with normal torque meters but seems to be more critical with the digital one. For the same reason the centerline of the meter hook - the point where the rubber motor or o-ring sits - needs to be really close to the centerline of the torque tube to minimize the effects of the motor being off-axis.

At this point I'm still buying and disassembling scales to find one that makes a neater and simpler installation.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on June 22, 2010, 02:18:24 AM
Bill,

have you found a scale with a LARGE display? My T-meter, from a cheap DealExtreme scale has quite a small display, and I think (have not tried yet) it will be hard to read that 2 to 3 meters away, that you need to stretch a F1M motor...

The force sensor seems to be a common circuitry of 2 strain gauges in a square bridge (thus temperature compensated). I tried to connect that to an op-amp circuitry that I have (for reading thermocouples), but for some reason I did not manage to get a proper signal out of it. Increasing amplification just drifted the base level higher, but gave no stronger signal, hence I did not get sufficient resolution of the reading. I do not know what went wrong, have to take a closer look in the autumn. Anyway, if that would have worked, then I could have used a micro-controller to output the readings in a serial format, and use any computer (hand held or whatever) as display, and getting a larger display to read.

I wonder about your binding problems, as the measurement should not be any different from conventional meters. What kind of bearings do you have on the meter? Can it be, that the sidearm is sticking to the sensor element?


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on June 22, 2010, 10:54:08 PM
Tapio

One of the scales I've got has a 1.5 x 4 cm display which is larger than any others I've looked at. It's the switchblade type scale. It also has a smaller weighing surface than the others and a mounting system for the load cell that would make it very easy to use. The drawbacks are that it's a little more expensive than the others at $15 and the part containing the display is 4" wide. This would add considerably to the bulk of the finished meter. (pictures below)

I think I can overcome any binding problems by using loose fitting bearings. The torque tube is suspended at the rear bearing by a full length .020 wire so there is no friction problem there caused by motor tension.

Others may disagree but I don't really use the torque meter until I'm pretty close in so readability isn't a big problem.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on July 06, 2010, 05:43:20 PM
Here's the URL for a 20g x .001g scale for $15.23 including shipping. I ordered one today in hopes it will be good enough to take to contests instead of my plug-in Acculab. I'll post a report when I get it in my hands.

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=280392289572


The scale described above came in the mail today. I tested it with an inexpensive set of calibration weights and found it weighed everything from 10mg up to its 20g capacity withing a milligram or two of the stamped weight. This is about the same accuracy as my Acculab Vic-123 that cost about $240. The disadvantage of this scale is the tiny weighing pan. This will call for some adapters to be made for it to be useful in the field.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on July 06, 2010, 11:07:26 PM
have you found a scale with a LARGE display? My T-meter, from a cheap DealExtreme scale has quite a small display, and I think (have not tried yet) it will be hard to read that 2 to 3 meters away, that you need to stretch a F1M motor...

Tapio

After destroying a number of scales I've settled on the one in the foreground of this picture. The one in the background has numerals that are .6cm high. On the foreground one the numerals are .9cm high. It has a backlight which goes off after about 25 seconds of no use. The scale turns itself off in 1 minute in spite of the instructions saying 3 minutes. Ordering this scale from China (from the USA) costs about $6. Here's the URL:

http://cgi.ebay.com/500g-x-0-1-Gram-Jewelry-Digital-Scale-Balance-Pocket-/250636775037?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item3a5b1dae7d


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: frash on July 08, 2010, 05:07:48 PM
The disadvantage of this scale is the tiny weighing pan. This will call for some adapters to be made for it to be useful in the field.

Bill, when you get the adapters acceptable for your use, please post what you have done. Others of us find the price right and the scale acceptable but hard to load onto the tiny thimble. I use a balsa platform on the thimble, but the thimble still shifts, and a larger platform obscures the readout. Nevertheless I use mine a lot.

Fred Rash


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on July 08, 2010, 05:16:45 PM
Hmmm, turns out I have the same scale too.

I just make a balsa base (square) that sits on top of the aluminum tray supplied (slightly bigger to not obscure the read-out). I glue a piece of small diameter wire to the base to create a hanger that I use to hand wings or tail surfaces from.

Seems to work fine.

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on July 29, 2010, 12:20:55 AM
Here's my solution to the small weighing pan:

I used a blob of 5 minute epoxy to glue a short length of 5/32 tubing to the center of the weighing platform. I tried to keep this tube as perpendicular to the pan as possible. Then I glued a 1 1/2" square of 1/16" plywood to a length of 1/8" carbon tubing - also with 5 minute epoxy. You could stop there but I thought it would be neat to not have to lift the plastic lid so I drilled a 1/4" hole thru the lid. Here are pictures of the 2 pieces separated and in action with a 2 gram weight on the extended pan.

I tried moving the weight around on the platform to see how much variation the scale would show. The answer was not much. The numbers would sometimes change a couple of milligrams. I think 1/10% is accurate enough for my purposes.

I also re-checked several of my (cheap) standard weights on this scale and on my Acculab Vic-123. The Acculab is very unstable for a good while after you fire it up so the pocket scale was clearly the winner if you're in a hurry. After the Acculab had settled down the weights shown on the two scales were within a couple of milligrams on all the test weights. And again, the Acculab was $240 and the pocket scale was $15.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on July 29, 2010, 05:08:39 AM
Here are a couple of chain drive, smooth as silk, 1-20 winders. No.2 is the test mule, which is a viable winder on its own, only it's a little ugly. They cost under $20 to make, and future ones will have GizmoGeezer's magnetic counter, or else provision for it will be made. There's one on the mule, but it wouldn't quite fit into No.4, which will have to be made about 1/8" thicker at most (No. 4 is 3.1 x 1.8 x 1.1).


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on July 29, 2010, 08:52:57 AM
Nice idea Bill.

Just out of curiosity, why did you make the carbon rod so long? Wouldn't it be better if the platform was just above the cover?

Nice winders Art. Reminds me of my old Mechano set!

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on July 29, 2010, 11:09:12 AM
Tony

Weighing whole models often requires some vertical space to get everything off of the surrounding obstacles. With the Acculab I have to put a model stand on it to hold the model high enough and keep it stable. I haven't actually tried weighing complete models on the little scale yet but may do so today. More adapters will probably be in order.

One thing I've been thinking about is a V shaped block of foam on the balsa platform that might work for weighing models with a variety of different MS configurations.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on July 29, 2010, 12:43:29 PM
I use a block of soft foam about 6" high. It doesn't need a "V" in it. Just put the plane on upside down.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Hepcat on July 29, 2010, 04:34:55 PM
The sketch below might suggest an alternative approach to dealing with the small scale pan on some digital scales. There is a beam with a pointer under one end to rest on the scale pan and a pivot near the other end. The pivot end of the beam can have a weight applied to give a near zero load to the scale pan before weighing begins.

There is a hook under the beam exactly half way between the scale pan and the pivot on which the thing to be weighed is hung. A hook is usually more convenient than a pan for the sorts of things that we weigh and in any case a pan can be hung on a hook!

A slight disadvantage of the arrangement shewn is that the weight registered on the scale must be doubled to get the actual weight. Other beam/pivot arrangements can do different things. We originally used 10:1 ratio beams to increase the accuracy of the early, cheap digital scales.

John


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on July 31, 2010, 12:47:20 AM
Bill, that is really neat. I did the same modification to my milligram scale, with a few twists: made the tube on the platform shorter, so that it fits under the clear plastic lid, which I can close to protect the platform. And I rebuilt m plane stooge to take the same 3mm carbon tube as shaft, so I can insert it onto the scale to easily weight the models. The stooge has a 10cm plywood disk as base, with a tubing of the same diameter as on the scale, so the plane holder shaft can be also inserted to that base.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on July 31, 2010, 03:14:37 AM
... two pics...


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: frash on July 31, 2010, 12:41:42 PM
Bill,

I copied your modification of the small, inexpensive balance also as I had previously "threatened" to do. Thanks to you and to Tapio who first found these balances if I remember correctly.

Fred Rash


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on August 01, 2010, 02:21:42 AM
Cannot recall for sure if it was me, or if I found the link to the scale on this forum... :-)

Anyway, preparing for the Belgrad contest, I made a stand for the digital torque meter to attach to my winding rod. Tested it on a couple of occasions, and it seems to work just fine. The torque readings are easily read, and seem correct (torque builds up while winding, and slowly fades away as the rubber gets tired). The current setup still holds the display and battery holder with rubber bands, as I will need to see later in the autumn, what position works for F1M. The current is ok for F1D, but "M"'s have so much longer motors, that the display maybe needs to be tilted to be seen from further away.

I'm using g*cm as torque readings, so the side arm is 1cm long. You can see the load cell, out of the scale, against which the side arm rests. The hook is of 1mm piano wire, and there is a sleeve of 2mm and 3mm brass tubing, acting also as the pressure bearing surface (some nylon sheet between the brass and the aluminium). A 3mm ID wheel collar works as a side arm, with a M3 bolt locking the collar to the hook wire. A washer between two nuts rest against the load cell, hence you can fine-tune the arm length by moving the washer between the nuts along the bolt.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on August 01, 2010, 10:47:59 AM
Tapio

In your torque meter are you taking the thrust load in the front bearing or the rear? It looks to me like it's the front but I wanted to ask to be sure.

I see you're using the same scale for your torque meter as mine. I'm glad it's working for you - I have 10 of them sitting here waiting for me to finalize the design for my meter.

On my milligram scale the hole in the top is not necessary for closing the top. I made the hole so that I could use the scale without opening it. I seem to always have a shortage of space when I'm flying so being able to operate the scale without opening the lid helps in that regard.

Art

The winders are very slick. One of the things that would make my torque meter setup easier is a winder with a hook closer to the bottom of the winder so the torque meter hook wouldn't need to be as high off the table. I guess this might be a future project.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on August 01, 2010, 02:59:21 PM
In your torque meter are you taking the thrust load in the front bearing or the rear? It looks to me like it's the front but I wanted to ask to be sure.

Front. The aluminum frame has 1mm holes to clear the hook, the 2mm OD (1mm ID) brass tubing is the length of the inside dimension between the two arms of aluminum frame, hence keeping the hook from moving to and fro, and also the front end of this tubing is the bearing surface to take the pull. Then there is a short length of 3/2mm tubing to sit on the thinner, and accommodate the wheel collars. The two tubings have some material removed so that the bolt in the collar meets the hook wire and locks it in place.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: wcstoddart on August 04, 2010, 11:51:41 AM
Art356A,

I like your chain drive winder and would be interested in making one. Please post more information here on the components that you used or contact me off-line at "chris 'dot' stoddart 'at' gmail 'dot' com"

best wishes,
Chris Stoddart


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on August 04, 2010, 04:28:30 PM
Hi Chris,

Nice to see you on the forums. This thing is still under development. No.5 is like No.4 but I tried to make it a little more accurately, which didn't completely work, so it has a few bushed and redrilled holes in the frames, so I could eliminate the takeup devices. I think the future ones will have takeup rollers, as they seem to have more pluses than minuses. No.5 has a simple reliable stop, and a tongue that slides into a slot in the near end of the base. It has a GizmoGeezer counter that picks up 2 pulses per crank, so you have to add that last zero. Future ones will have a Red Lion Cub3 (I think) which will count individual turns off the hook shaft. If the builder doesn't want a counter he can leave it off, but these digitals are so head and shoulders better than an analog dial, I can't see trying to save the forty bucks or so that they cost.

The present plan is to make up a tutorial for SFA, but I won't do that until I develop it into something that can be easily and reliably built by anyone capable of building a Hangar Rat or a Phantom Flash.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on August 04, 2010, 05:51:17 PM
Oh, I forgot. The source for the innards is Servo City. I use two 40 tooth wheels, one 10T, one 8T, and a foot of chain. This runs about $8.50 plus $6 s&h. Everything else is off the DuBro and K&S racks at your LHS. Or HomeDepot if you want to make the frames from Lexan.

I'd love to have somebody else working parallel with me, so we can bounce ideas around.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: wcstoddart on August 04, 2010, 06:05:22 PM
Hi Art,

Thanks for the information. I will place an order for the parts from Servo City and after I have them in hand get in contact with you. I will be traveling next week so don't expect to hear from me until after August 16th.

best wishes,
Chris


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on August 16, 2010, 06:45:02 AM
So the Belgrade WC saw the first serious action for the digital torque meter. And I must say that I am all satisfied with the results. First of all I learned that I do not wind my motors tight enough, and learning for that would have run out of scale on my mechanical TM. But more than that, the digital meter has so much better resolution, that you can much better see what is going on in the rubber. For instance, I have always known that when I stop winding and hold the motor still, it slowly loses torque. But I never knew before, that if I back off, the motor gains a little torque as it settles to the new position!



Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on August 16, 2010, 09:45:28 AM
Tapio...

I'm happy that it's working out in practice, rather than just on the bench. Shows the difference between me, who simply observes the phenomena, and you who knows how to observe, interpret, and put the data to good use. That said, I still think that all the emphasis on elaborate thrust bearings is totally unnecessary because there's no rotation occurring here, only a transfer of force direction. A nylon or teflon bushing more than does the job. The fact that when you stop winding you see an instant drop in torque proves that it's working.

Meanwhile, the effort to come up with an accurate counter on the "Frazer-Nash" winder is costing a lot of time and money, but I think I'm getting closer. As the winder gets more costly and bulky, I'm becoming less convinced of the necessity of a turn-by-turn count, as opposed to counting every tenth turn. Is there really a useful difference between 2512 turns and 2517, particularly when, as the torque builds, you've switched away from the counter and onto the torque meter? Somebody please agree with me, as a 10-turn counter is easier, cheaper, and lighter.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on August 16, 2010, 11:26:25 AM
Art

I totally agree that counting individual turns is not necessary. Most indoorists do not use counters at all. For me this means that I long ago learned to think in winder turns instead of actual turns. On my 20:1 winder I have a counter made from a pedometer that counts crank turns. I think I've posted it before but if not here's a pic. I've been using it for a number of years and have been totally satisfied with it. It has a slight flaw in that if you crank too fast it will miss some of the turns. This is actually not a bad thing since cranking fast is a bad idea anyway. The only exception is at the end of a contest period when you're trying to get in that one last flight before time is called.

I think the pedometer cost around $12. The other parts required are a reed switch (from Radio Shack) and a magnet. The reed switch is wired into the pedometer in place of the pendulum mechanism.

I think you're probably right that the torque meter bearing isn't extremely critical. To be absolutely correct though there is some rotation occurring in the bearing - otherwise there would be nothing to measure on the load cell. I actually measured this one day but don't remember the number now. I think it was on the order of a few thousandths of an inch. If the deflection is .005" with a 1" arm then the rotation is about 1/4 degree.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: PeeTee on August 16, 2010, 11:43:57 AM
You can also use pocket or key ring calculators taking a wire off either side of the equals (=) button and run it to a reed or microswitch. The calculator can be 'programmed' to the winder, which is useful for outdoor winders with difficult ratios such as 3.75:1. For example, with 20:1, you enter 20 +, and then every time the = key is pressed (or the switch activated) it increases the total by 20. As Bill says, the only drawback is that if you wind too fast the switch can bounce and miss turns.

I can't claim credit for this idea, as calculator & microswitch kits are available for about a fiver (£5) from our invaluable cottage industry FF suppliers.

Peter


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on August 16, 2010, 11:49:08 AM
In the champs, my teammates (and others) kept asking me, "how many turns did you pack in?" I could not tell, as I do not count them. Agreed, it would be useful additional information to know, at what turn number you reach a given torque, so I will need to implement a counter later. But, IMO, torque meter is way more important than the turns counter.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on August 16, 2010, 11:51:05 AM
My two main problems have been a double count at unrealistically slow speeds and missed turns at faster, but realistic, speed. I think the problem is too small a magnet. It kicks, releases, and then kicks again on a slow pass of the reed switch. Bigger magnets are on order. I like the pedometer. If you tried to use it on the output shaft you'd probably find that it couldn't handle the frequency, which could reach 60-65Hz. Anything will pick up 6 or 7Hz.

Radio Shack no longer carries the reed switches, but I have a friend who is a burglar alarm guy, and he has an unlimited inventory of several different kinds and has been teaching me the ins and outs of working with them.

If the bigger magnets solve the problem, then this one will be functional. After that I'll go back to the 10-turn count. Less aggravation.

The beauty of the calculator is that the feed is at cranking speed, and the readout is whatever you want it to be.

To return to the thrust bearing question: Nope, I don't buy it. These scales sense pressure, not travel (like a spring scale). Even if 2 ounces makes them deflect .010 (which it doesn't) the deflection would be taken up by the slop in the system. Again, the fact that the scale registers an instant drop in torque the moment you stop winding shows that it's picking up minute differences in force without the herioc thrust bearing measures.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on August 16, 2010, 03:20:50 PM
Okay... success at last... sort of. Bigger magnet and an alarm reed switch rather than a raw ampule type. The double hit at low speeds is cured, and I have to crank it at ridiculously high speed for it to skip.

It'll have to do.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on August 16, 2010, 04:37:59 PM
To return to the thrust bearing question: Nope, I don't buy it. These scales sense pressure, not travel (like a spring scale). Even if 2 ounces makes them deflect .010 (which it doesn't) the deflection would be taken up by the slop in the system. Again, the fact that the scale registers an instant drop in torque the moment you stop winding shows that it's picking up minute differences in force without the herioc thrust bearing measures.

Art.

I think they measure bending stress in the load cell. No movement = no stress (or pressure if you want to use that term). Use a feeler gauge under the load cell if you don't think they move.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on August 16, 2010, 04:42:37 PM
In the champs, my teammates (and others) kept asking me, "how many turns did you pack in?" I could not tell, as I do not count them. Agreed, it would be useful additional information to know, at what turn number you reach a given torque, so I will need to implement a counter later. But, IMO, torque meter is way more important than the turns counter.

Tapio

Both are important. Subsequent winds of the same motor will generally yield more turns but you might not reach the same max torque as on the first wind. I'm sure with all the rubber testing you've done you've seen this effect. Most indoor flyers don't have counters on their winders but I've never heard of one who didn't count turns.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: applehoney on August 16, 2010, 05:03:10 PM
Count turns? I noticed two years ago that the counter on my Sidewinder wasn't working. I hadn't missed it, I've never missed it since; I trim to torque meter readings, note that which gives most performance and fly to that thereafter.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on August 17, 2010, 01:12:00 AM
Both [turns and torque] are important. Subsequent winds of the same motor will generally yield more turns but you might not reach the same max torque as on the first wind. I'm sure with all the rubber testing you've done you've seen this effect. Most indoor flyers don't have counters on their winders but I've never heard of one who didn't count turns.

Agreed. But still, torque is far more important than the turns. Actually, now after the champs I am in a middle of a thinking process of how using rubber in indoor and outdoor events differ. Outdoors, we find pretty fast and are happy if we can launch quickly, before the max torque starts to drop. Indoors, the winding takes much longer, and in the process we even let the motor stand for a while, to let the torque drop a little, to be able to pack in more turns. Sure enough, also for outdoor models people tend to stop the winding every now and then, and slightly pull and release the motor, definitely to make the knots fall in more evenly. But yet I feel that there is a fundamental difference in the way the motor is used, indoor and out, with the former giving more emphasis on the number of turns, and the latter to the overall energy. But as I said, my thinking process of this subject is only "in progress" at the moment.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on August 17, 2010, 11:45:22 PM
But as I said, my thinking process of this subject is only "in progress" at the moment.

My thinking has been "in progress" for a number of years now! I don't fly F1D but F1M has similar challenges and I think I understand F1M rubber requirements fairly well. The flying that mystifies me the most is in the classes with no rubber limits and no VP's. At USIC this year I was flying similar times to people using 60% or so of the rubber weight that I was using. My approach is almost always thick rubber, heavy rubber weight, low torque and slow climb. Others do the opposite on all counts and do well. It's a never ending puzzle to figure it all out.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: frash on August 18, 2010, 05:53:41 PM
Thanks, guys. I've previously learned from at least three of you.

Counting only winder turns (and turns remaining upon landing) works for me and for the Science Olympiad students also. I always record torque before and after also.

I once argued on another forum, partially seriously, that winding is too important to leave to a mechanical device. Since I believe that counting winder turns helps me to concentrate, that is what I do and I always ignore the counter on the Wilder winder.

One indoor modeler who mentored Science Olympiad Wright Stuff students said that he taught his students to concentrate during winding by saying random numbers while they were winding for practice flights. I have told some students this, but have not actually spoken random numbers to test their concentration. Once one of them tried this on the other one who was winding. <Grin>

Fred Rash


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on August 19, 2010, 01:52:56 AM
I once argued on another forum, partially seriously, that winding is too important to leave to a mechanical device. Since I believe that counting winder turns helps me to concentrate, that is what I do and I always ignore the counter on the Wilder winder.

Fred

I've found that the older I get the more I like my counter!


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: faif2d on August 19, 2010, 09:36:49 AM
What strikes me as interesting about this type of torque meter is that it may work in outdoor applications as well. I have seen one that used a dial indicator for the scale but that allowed for to much movement of the airplane to rotate about the axes. This with essentially no movement should work. I will probably never try it but would like to see someone else give it a go.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on August 19, 2010, 10:28:36 AM
Years ago Bob White had a stooge mounted torque meter (made by Bob Wilder I believe) that was mechanical. The drawback was that strong winds would rock the model and throw the readings off. Walt Ghio got around this by winding with the wings off. Today, with the advent of the 1/2 tube system of external winding a mechanical or electronic stooge mounted torque meter is far more practical. I did see Evgeny Gorban (Ukraine) using a mechanical version on his stooge at the Maxmen with good results. I watched him wind several times and could observe the entire torque build-up as he went along. Very cool! I've never really liked the winder mounted torque meters as you have to stop periodically to check the torque.

I must think about an outdoor electronic version for F1B/F1G.

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on August 19, 2010, 02:06:51 PM
Here's the plan for the meter I'll start making next month. I had hoped to have the aluminum parts made by someone else but the cost was too high. Projected selling price is in the neighborhood of $50 but a final decision will depend on how much time it takes me to do all the cutting and drilling.

I think it will be important to have the winder hook the same vertical distance as the torque meter hook to keep from putting an eccentric load on the meter. On my Geauga winder I can move the mounting plate to a different location on the winder to make this happen. I don't know how this will affect users of other types of winders. If a winder mod won't do the job then it may require a block under the meter base to get the correct alignment.

In the meantime I've made some repairs to my original wood version and will take it to Lakehurst for the Labor Day weekend. I'm taking my old meters as backups.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Alan Cohen on August 19, 2010, 03:11:58 PM
I love this. I think this is one of the coolest innovations for indoor flying in a long time. Definitely falls into the category of "why didn't I think of that?!" Nice goin' Artie!!!


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: gvwezel on August 19, 2010, 03:18:34 PM
oke
hello i new in this topic oke in this world of f1d and i want to build a torque meter.
now i'm reading all about the digtial version so now i want to know how many grams of torque will F1D rubber gif?
also a want to now if you using al the time the same torquemeter than its oke thats is not kalibired?
hope all of you can help me

gertjan van the netherland starting f1d


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on August 19, 2010, 06:12:27 PM
F1D motors will do around 40 gram-centimeters of torque.

Using an uncalibrated torque meter is fine unless you want to compare your information to that of someone else and then it is definitely not good.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on August 20, 2010, 10:59:58 AM
So to sum up, although that may be premature...

Fred says to pay no mind to the number of turns or the numerical value of the torque. Feedback thru the crank handle is all that matters.
Joshua says that counting every tenth turn is not sufficient. Alan's Minislick ran 3525 turns on her record flight. Can you really read the difference between 3522 and 3528 on a scale that divides into 500 parts? I've seen Joshua, after checking the turns and the torque, lay hands on the motor and palpate the knots before deciding if the model was ready for flight. What's that about and how would one quantify it? He laid hands on one of my motors once and the plane really flew nice after that.

Hepcat says that it's important to have a calibrated torque reading so we can communicate with our colleagues (Bill just reiterated that). That's what my contraption addresses. I think it's already an order of magnitude more accurate than the wire, tube & disc instruments, so I'm a little put off by the folks who are unnecessarily gilding the lily on the thrust bearing thing (although I can't fault Tapio's craftsmanship).

Tapio figures that there's a relationship between winds, torque, resting time, and how many flights on a motor that needs much more study than it's been given. Think Mass Launch... You've got all your numbers right on the button and then you have to wait for the last launcher to be ready as your torque drops. Is it part of the strategy to be the last launcher ready?

So... The more I learn the less I know. Just like life itself.

Meanwhile, I've knocked out a couple of more Frazer-Nash winders, although I haven't been able to find cheap counters like Peetee's. The pedometers I've found are way more than $12, but many of them will also tell you your heart rate and blood pressure. That can't be bad. There are two $18 low frequency counters in transit to me now which will just need to be slightly modified to make them resettable. At this point I'm approaching something duplicatible which I can draw plans for. There's still a lot of hand diddling involved which I want to eliminate if I can.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Alan Cohen on August 20, 2010, 11:47:34 AM
For indoor, torque is most valuable because it keeps your model out of the ceiling. A very good thing indeed. Launch torque controls height, period. Turns are important if you really want to maximize duration by dialing in the motor length once you have an idea of the proper cross section necessary for your prop. Of course we don't want extra length which translates into more weight, less duration.

Ideally, when winding an indoor motor, you wind to just shy of max turns and then back off to the desired launch torque. That number could be 100 to 500 turns depending on the class of model. When the model lands it should also have turns left. In order to use the rubber energy efficiently, it has become common practice to center the flight portion of the motor run. In other words, if you back off 200 turns at launch, you want 200 turns left on the motor. If you are backing off 200 and have 500 left, shorten the motor. If you have 100 left, use a longer motor.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on August 20, 2010, 12:29:24 PM
Nice to hear that, Alan. I've been spending time, treasure, sweat and a little blood refining these things. I'm learning a little more with each one about what factors of sloppy manufacture make them feel notchy and how to correct them. They're still cheap to make, but I'm trying to transfer the tuneup work into the initial layout so that they'll have minimum parts (like idlers, which are essentially there to correct layout mistakes) and run smooth right off the bench. It's good to know that it's not all for naught.

Oh, I forgot to mention that you've laid hands on one of my models, too, and it flew much better for it.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: PeeTee on August 20, 2010, 01:31:30 PM
Art

I've only just read your post about cheapo pocket calculators & immediately put "pocket keyring calculator" into the search engine and came up with this:

http://www.sourcingmap.com/pocket-digit-key-chain-red-calculator-p-14902.html?currency=GBP&utm_source=google&utm_medium=froogle&utm_campaign=ukfroogle

As it quotes prices in GBPounds I suspect that it's an offshore supplier, but at less than £2 it should work out the same in dollars, or no more than $3. I also spotted a site selling Radioshack calculators which were cheaper, but it stated "out of stock". I'm sure you could find something cheaper quite easily ;)

On the outdoor torque meter front, I spotted a torque sensing stooge (no not me ;D) at Poitou which looked quite neat. It was for winding motors external to the model, and when i find the photo I took I'll post it here.

Keep up the good work as what you are doing is brilliant.

TTFN

Peter


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Alan Cohen on August 20, 2010, 03:43:41 PM
A suggestion on the winder. Make the wire handle as beefy as possible. You do not want any flex there. Makes for better feel of the rubber.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on August 20, 2010, 04:52:00 PM
One thing I know for sure is that nobody is in much agreement how to do anything in indoor duration. One of my flying buddies told me recently that two of the top USA fliers always do their back off by counting turns - not by going to a torque number. I do the opposite. I always back off to a torque value that I think will get me to the ceiling without getting hung in the process.

As far as centering the turns used in the max turns in the motor I agree that's a good point to aim for but when I look at my flight data I don't see that happening. I nearly always have from 2 to 4 times the number of turns remaining as the number I back off. Shortening motors to change this relationship is a slippery slope. A shorter motor wound to the same torque puts a lot more stress on the motorstick. Some models will handle this okay but mine like to dive in at launch if I overdo the motorstick bend a little. This is at least partially due to my trim method that I've talked about before.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on August 20, 2010, 04:54:54 PM
One of the earlier ones was made of .047 wire because it was a nice fit in the Tefzel bushings that were available in the stash. I could feel a little flex in the crank as I pushed 2K turns on an H-Rat motor (which is the heaviest motor anyone uses indoors, right?). There was also a fabrication problem in keeping the .047 wire centered in a tube that was .063 square inside. The current ones have .063 wire running in bushings sliced from Gold-n-rod or Nyrod which are ±.070 ID. Nice and beefy.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Alan Cohen on August 20, 2010, 05:16:28 PM
Perfect.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on August 21, 2010, 12:14:40 AM
Talking about winders: In Belgrade my yellow K&P felt a little "rough", as if it needed some lubrication. What kind of maintenance do these units require?


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: applehoney on August 21, 2010, 12:51:52 AM
None .. may just be overstrained?  Does it rattle? There are five tiny ball bearings .. I had one winder go belly-up years ago and I found that their retaining ring had worn and allowed one to escape. If you take it apart do so with care for the balls will drop out and I know that one can vanish forever into the pile of the carpet..... ::) If anyone needs replacement bearings I have four ......


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Hepcat on August 21, 2010, 12:29:59 PM
I have just finished reading Mike Burrows’s book ‘Bicycle Design’. Mike is the chap who designed those aerodynamically efficient, monocoque machines (sometimes known as the Lotus bikes) that helped Chris Boardman to gold at the 1992 Olympics. He also did design work for Giant, the largest cycle maker in the world. Very interesting you say (yawn) but what has it to do with aeromodelling?

Mike and I were Young Modelling Buddies back in the fifties and sixties and he was probably the best English glider flyer of the time. His designs had skinny wing sections, he kept pushing aspect ratio higher than anyone else and, probably most important, he introduced the world to tubular tail booms in the form of glass fibre fishing rods. OK, you say, so he was an aeromodeller but where does that fit in with winders and suchlike?

I was coming to that. In the transmission chapter of the book he reminded me of something I had forgotten although Art (being the consummate engineer that he is) obviously had not. Chain drive is the most efficient way of transmitting power – better than gears and far better than rubber toothed belts. No wonder his winders are impressive.

Art, have you thought of adding a derailleur mechanism so that you can provide gear ratios of, say, 5:1, 10:1 and 20:1 in the same unit? :)
John


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on August 21, 2010, 03:45:02 PM
John, did the F-N reference provoke that idea?

I'd like to think that Archie is up there somewhere, smiling down on the effort. MacReady used chains, too, but I never saw any credit to the heritage, only the corporate sponsors.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on August 21, 2010, 06:16:14 PM
K & P have 1:5 and 1:10, and they're inexpensive. An inexpensive 1:20 machine doesn't exist, and a 1:20 machine with an accurate, easy to read counter doesn't exist at any price. That dearth is what I'm trying to address. The intermediate shafts on mine run at 1:5, but they just float within the frames and aren't hooked up to anything.

One machine with multiple outputs is beyond my intellectual and fabrication capacity. I'd think that 3 machines would take up less room in the toolbox than one with multiple outputs (and cost a lot less money).

The unit in the background in the previous post is all set up with the sensor and reed switch, and the $18 counter should be here in the middle of the week. It will need to be modified to make it resettable, but that won't be a big deal. It will count by tens.

I have some thoughts on an outdoor torque meter for Peter. Maybe I'll try to make one up in a Peanut/Bostonian size to see if it comes together. If it looks good somebody can make a big one. I think a big one would have to read gm/cm's so we could work with a 4 inch arm rather than a 1 inch. I know that inexpensive scales are available in the right weight range.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: gvwezel on August 28, 2010, 02:10:47 PM
Hello people

Here the new builder from the Netherlands how want to build a digital torque meter.

Okay here is a summary as I think you build a digital torque meter and if wrong then correct me.

Because with this information, I would build one.
- the wire that's in the analog torque meter torquedraad was (pianowire) should not twist the digital one, so no twist at all.
- So this is the best one to use a brass tube .
- all should be well trapped between two points so that no friction.
- I would torqeudraad between the measuring element by let. The measuring element is vertical put down.
- Between the element I make a reticle rotation so that he will press on the element.  He pressed the two component parts will separate.

okay this is what I think to do. I hear what you think.

And yes sorry for my bad English but I hope it is clear

Greetings Gert-Jan from the Netherlands


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on August 28, 2010, 09:14:21 PM
Hello people

Here the new builder from the Netherlands how want to build a digital torque meter.

Okay here is a summary as I think you build a digital torque meter and if wrong then correct me.

Because with this information, I would build one.
- the wire that's in the analog torque meter torquedraad was (pianowire) should not twist the digital one, so no twist at all.
- So this is the best one to use a brass tube .
- all should be well trapped between two points so that no friction.
- I would torqeudraad between the measuring element by let. The measuring element is vertical put down.
- Between the element I make a reticle rotation so that he will press on the element. He pressed the two component parts will separate.

okay this is what I think to do. I hear what you think.

And yes sorry for my bad English but I hope it is clear

Greetings Gert-Jan from the Netherlands

I don't think I understood very much of that message but in general I think you're on the right track.

I'm going to Lakehurst next weekend and am currently testing motors using my prototype wood torque meter. It seems to be working fine and is much quicker to read than my old twisted wire meter. I modified my Geauga winder to put the output shaft at the same height above the work surface as the hook on my digital meter. This turned out to be a lot harder than I thought it would be but the end result works fine. I'm thinking now that I need to mount my winder and torque meter on the top of my model box so that I won't need to figure out a table top mounting system at Lakehurst.

So far all of the F1L motors that I made for Lakehurst are taking less winds than I need to have a shot at the Cat IV record. I may have to start over with longer and/or thinner motors.

Here's a picture of my model box that I hope to carry on to my flight to NJ. It has two F1L's and two LPP's inside.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on August 29, 2010, 01:48:43 AM
Quote
the wire that's in the analog torque meter torquedraad was (pianowire) should not twist the digital one, so no twist at all.
- So this is the best one to use a brass tube .

It does not make any difference, whether the torque rod twists or not. As a matter of fact, you could use thin piano wire as the rod and still measure the torque with electronic scale, if you set the back support so that it exerts the force onto the scale. After all, measuring the torque is based on: 2 pivot points, around which the torque rod rotates, ans the support point at a given distance from the rotation axis.

In my implementation I used brass tube (where the piano wire for the hook goes in) as it gives a simple way to make the bearing surface to take the axial load resulting from the pull of the rubber.

Quote
all should be well trapped between two points so that no friction.

Yup, you need the two pivot points so that the setup does not flop around, but the torque arm (length) is stable. All friction in the pivot points makes the torque reading less accurate, as if (of course) the case with also analog torque meter.

Quote
I would torqeudraad between the measuring element by let. The measuring element is vertical put down.

The arm that pushes to the scale should be perpendicular to the load cell of the scale. But actually, as the movement of the scale is minimal, it does not make that much error if it is not, the reading should just be corrected with the cosine of the movement angle. The placing of the load cell and side arm is irrelevant, the arm can push down, sideways or even up, as you are measuring torque, and the effect of gravity on the arm needs to be tared off anyway. Pushing the load down as in my implementation is most convenient, however, as that way you can use the gravity to hold the (unloaded) arm against the load cell.

Quote
Between the element I make a reticle rotation so that he will press on the element. He pressed the two component parts will separate.

Sorry, I do not understand the above. I gather that the sentence means that you install the side arm between the two pivot points, and it will press on the load cell of the scale. That is correct (while actually there is no need for the side arm to be between the pivot points, but that is probably the most compact design). In the second sentence, I do not know what two components you are referring to.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: gvwezel on August 29, 2010, 06:00:24 AM
thanks for the info
okay it is difficult to explain.
but manage to guide you now to build one of the building will still try to send some pictures.
would also like to try calliberen as a standard analog torqeumeter.
nice box (sorry you know name)
is the standard case with a stake in it made?

greeting Gert-Jan


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on August 29, 2010, 09:33:58 AM
Gert-Jan...

Just follow the pictures and build anything that looks like the simplest one here and you will have a meter that is 100 times more accurate and readable than the disc & wire type. Any sort of thrust bearing that works on a model plane will be more than good enough for the torque meter. On the other hand, you can spend 1000 Euros and a month of work to make a frictionless bearing, and your meter will be 101 times better than the common type.

 Just my opinion, but I'm a simple person.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: gvwezel on August 29, 2010, 01:14:45 PM
oke Art

that's what i like yes i will build something like the photo's on this forum.

thanks


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on August 29, 2010, 10:53:57 PM
is the standard case with a stake in it made?

Gert-Jan
If you are asking about my model box it's a 20" long plastic tool box sold at Fry's in the USA. My LPP and F1L wings are a little less than 18" span. The box is also a little less than 18" wide at the bottom. The wings barely fit in the box. An F1M wing made to the full 46cm span would not fit unless it was placed on the diagonal.

Here's a link to the box:

http://www.frys.com/product/3602025?site=sr:SEARCH:MAIN_RSLT_PG

 I used hot melt glue to hold the balsa sticks to the bottom of the box. I'm thinking of painting the box black to make it less threatening at the airline check-in!


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Wout Moerman on August 30, 2010, 04:29:44 AM
Hello people

Here the new builder from the Netherlands how want to build a digital torque meter.

And yes sorry for my bad English but I hope it is clear

Greetings Gert-Jan from the Netherlands

Hoi Gert-Jan,

Mooi om je hier op HPA te zien, wanneer je hulp nodig hebt met het engels kan je altijd op mij een beroep doen: w.moerman(@)amd.ru.nl (en de haakjes weglaten). Ik begrijp dat je nu een torsiemeter gaat maken zoals hier al eerder beschreven staat? Dan kan het handig zijn om eerst te beslissen welke eenheid je wilt meten, ounce per inch of gram/cm. Dat bepaalt namelijk hoe lang de arm moet zijn die de weegschaal bedient.
Ik ben benieuwd naar je vorderingen!

Wout

Short translation
Hi Gert-Jan, nice to see you here at HPA, if you need help with your English you can always ask me for help. If you start building a torque meter decide which units to use: oz/inch or g/cm


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Wout Moerman on September 01, 2010, 05:36:41 AM
Update, Gert-Jan has contacted me via e-mail and we are discussing this topic in dutch. I've suggested him to use g.cm instead of oz.inch as unit, and I noticed I earlier made the mistake of mentioning oz/inch or g/cm as units. My fault.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on September 01, 2010, 10:41:47 AM
I think g.cm would be better. First, he's European. Second, with a longer arm he doesn't need to make a dog-leg on the supporting frames to get the end of the arm onto the middle of the tray. Would there also be an accuracy advantage with a centimeter long arm rather than the .394 cm arms that we use over here?

a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on September 01, 2010, 10:44:23 AM
I'm using a 1" arm with the scale set to read in ounces to get a direct reading in in-ozs.

BTW - I've been testing motors for my Lakehurst trip using my digital meter. This has been going on for several days now and I've been happy with the performance of the meter and the ease of use. My only problem has been that the scale portion of this meter shuts off every time I have a pause in the action. The only way I can keep it on is to press down on the arm for a couple of seconds when I don't have a wound motor on it. I'm hoping that the new scale innards will not be as quick to shut down. So far I've never had it shut off while I was actually winding or unwinding for energy tests.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: craig h on September 01, 2010, 02:10:39 PM
You guys built a really nice torque meter and winder combo.... but it's way out of my skill level ! I don't have the expertise or skills to build one .... but it's nice to read about it.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on September 01, 2010, 02:31:47 PM
Craig...

The winders are a female dog and a half to build. I've just finished the eighth one (including recycling earlier ones) and it's a gem, but I'm not yet entirely sure they're duplicatable. That's what's holding back the plans. It may be that unless you'e a CNC guy (I'm not) each one will need its own tuneup.

The torque meter, on the other hand, is simplicity itself. Just read reply #140 and do what it says. Anyone capable of building the simplest stick and tissue job ought to be able to knock one off in an hour or two.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on September 01, 2010, 02:35:30 PM
Ya gotta love that V-Chip, dontcha?

My best pal is a little black 'female dog'. Actually, she's an alliteration, but v-chips don't appreciate alliterations.

a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on September 10, 2010, 04:31:49 PM
Lakehurst trip was a bust. 2 days in the hangar watching the wind blow and then one flyable day on Monday. My LPP fell a couple minutes short of the Cat 4 record.

OTOH the torque meter worked great. The only problem I had was remembering to turn it on before I started winding. Even that's not a big problem. Since the input shaft hardly moves you can just unhook the motor, turn the meter on, put the motor back on and keep winding.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on September 19, 2010, 12:58:31 AM
Here are some pictures of the first digital torque meter of the production design. A few details will be cleaned up but this is basically what you'll get. The overall size is 3" wide x 4 1/4" long x 1 1/8" high.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on September 19, 2010, 01:55:03 PM
Since the input shaft hardly moves you can just unhook the motor, turn the meter on, put the motor back on and keep winding.

It's easier than that. Pick the arm up off the sensor, turn the scale on, put the arm back down.

a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: craig h on September 19, 2010, 02:40:08 PM
Your torque meter looks nice and definitely high tech in my eyes of view. So are they going to be offered to the public?

Craig h


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on September 19, 2010, 03:20:18 PM
Your torque meter looks nice and definitely high tech in my eyes of view. So are they going to be offered to the public?

Yes but not quite ready yet. Also I don't think we are supposed to advertise for sale items here so when a couple of changes are worked out I'll put an announcement in the right place.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on September 19, 2010, 03:24:06 PM
Since the input shaft hardly moves you can just unhook the motor, turn the meter on, put the motor back on and keep winding.
It's easier than that. Pick the arm up off the sensor, turn the scale on, put the arm back down.
a.

If you do that you will be ignoring the weight of the arm and any preload on the arm. In my case the reading would be .05 in-oz higher than the actual torque. For sport flying this might not be a problem. For competition it probably would be a big problem. For instance, an EZB in a high ceiling site might be launched at .10 in-oz or less. If the meter is reading .05 in-oz too high then you could be launching at half as much torque as you want.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on September 19, 2010, 07:33:18 PM
I didn't take into account how overbuilt yours is. My arm only adds .0035 oz/in. and I'm only a sport flier anyway.

My scale has a 100gm (3.5 oz) capacity so the light construction is okay for it. You might think about a counterweight for yours. What's the max on your scale, and if it will support Moffetts and Wakefields what do you have in mind for either mounting the whole model on the device, or making a winding-outside-the-plane system?

a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: julio on September 19, 2010, 08:33:30 PM
Your torque meter looks nice and definitely high tech in my eyes of view. So are they going to be offered to the public?
Yes but not quite ready yet. Also I don't think we are supposed to advertise for sale items here so when a couple of changes are worked out I'll put an announcement in the right place.


Olbill, I'm not either an expert nor a pro. I don't build as often as many modellers here. I'm not into competition also. So please take this as a humble and constructive opinion. Taking your words "but not quite ready yet" (to be offered to the public), do you think possible and helpful that the display of the torque meter could be set at an angle (45º or more) facing the modeller while winding the motor in order to have a continuous reading even from a "long" distance? Do this make any sense or your experience with this device demonstrated not necessary such a thing?

Don't take it bad please, just trying to give a positive input.

Regards
Julio


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on September 20, 2010, 12:30:28 PM
Julio

The angle of the scale readout is a problem that I'm aware of. It doesn't have a simple solution. As Tapio pointed out elsewhere the numbers are most easily read when your eye level is perpendicular to the display. If you move your eyes "above" that line the numbers fade out at an angle of around 25 degrees. If you move your eyes "below" that line the numbers are still readable at around 45 degrees before being blocked by the lower edge of the display. On my first meter I discovered this effect when I mounted the readout at about 60 degrees and couldn't read the display when I was all the way in and making the final torque adjustment. I took that one apart and remounted the display as flat as I could get it which was around 45 degrees. The meter became usable at that point.

For the new meter the display angle is limited by the space below the rubber hook. I've worked out a fairly simple way of mounting the display at a 15 degree angle. Going to a steeper angle than that would require using a larger channel and an extensive redesign.

I realize that some people will see this as a limitation. It's not a problem for me because I don't use the torque meter until the last part of the wind. My normal winding method is to stretch to 5 to 6 times relaxed length, put in 50% of the expected number of turns and then use mostly the feel of the rubber to gauge how fast I come in. Close to the end of the wind when I'm at most a couple of feet from the winding rig I'll start depending on the meter to finish up the wind. With the meter display at a 15 degree tilt, the meter at 30" from the floor and my 6' height I can read the meter from a distance of around 7 feet.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: ykleetx on September 21, 2010, 02:58:31 PM
If you do that you will be ignoring the weight of the arm and any preload on the arm. In my case the reading would be .05 in-oz higher than the actual torque. For sport flying this might not be a problem. For competition it probably would be a big problem. For instance, an EZB in a high ceiling site might be launched at .10 in-oz or less. If the meter is reading .05 in-oz too high then you could be launching at half as much torque as you want.

I launch my EZB at .08 in-oz, so I need the accuracy at the low end. .05 in-oz error might be okay for penny planes (or outdoor) but not for anything else indoors. Even .005 in-oz error is too much for EZBs, in my opinion.

Thanks, Bill. Can't wait to get hold of one in my hands!

-Kang


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on September 28, 2010, 03:08:32 PM
This is all done. A laterally adjustable layshaft eliminates the idler/tensioner wheels, and the necessity for precision fabrication beyond the scope of the home workshop. There's NO friction, nor is there pulsing from the reed switch (which earlier ones had a little of).

The counter, which isn't quite on the market yet, handles 10KHz input, so I set it up to count the actual output on the hook shaft. The fastest I can crank it, which is never done in real life, is .006KHz. For the advanced flier, who winds tight and then backs off, snap the red switch down and it counts backwards. It has 8 digits...we only need 4, but you can't always get what you want. But if you want 2450 turns and then back off 500, you don't need to remember how many times that 500 dial maxed out; just read the display (which, BTW, is 5/16" high).

This version is a little longer than the early ones, so you'll need a second foot of chain @ $6, but the winder still comes in at less than $30 plus a bit of s & h. The reed switches should run about $3 and are in stock at your local burglar alarm installer. The counter will be $32 and includes a 10 year lithium battery.

My winders have all been 1:20, but they can be made in any ratio you want.

art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on September 28, 2010, 03:49:03 PM
Are you planning on selling your winder Art? (he asks pleadingly...).

Very nice by the way and I love the see through plexiglass to look at the internal workings. Very cool!

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on September 28, 2010, 07:28:23 PM
Right now I have to make some new drawings so Chris Stoddart can do a Beta Build, after which, if he completes it successfully, it might get published in FFQ. The original intent was to run it as a tutorial on SFA, but there hasn't been much interest in it over there. I feel bad about that, as I'm moderator of "Tools and Techniques". I think PFFT would probably run it, too.

I've had a lot of help from Bill Carney, Joshua Finn, and especially Orville Olm (the GizmoGeezer) and I have to acknowledge their guidance and encouragement, without which I probably wouldn't have gottten this far.

I'd enjoy doing a short run of them, especially if I can make up some templates so I could mechanize things a bit, but I don't begin to know how to price them. Parts and material costs are as I've quoted here, and my only savings there would be cutting a little s&h by buying 40 sprockets at a time instead of 4. I'd save 2 bucks per counter if I bought 10. The plans builder would need to buy two $6 lengths of chain to get the necessary 13.6 inches, and I could make ten winders with 12 lengths.

Mostly, there's a full day of (enjoyable?) work to make one, and that's after having built 8 or 10 of them. The first ones took two days. It's like Alan said... he can build a Minislick in a day but it took two years for him to teach himself how.

So I dunno, how does parts, mat'l, packaging and posting plus $50 sound? Should put it in the $110 area delivered.

I suppose I could run up a batch once I know Trumeter's production schedule for the counter. Having played with a prototype 7111 I don't even want to think of going back to any of the others I've tried.

a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on September 29, 2010, 03:21:09 PM
$110 is half of what the only other available 20:1 winder costs.

I think it would be a good idea to have some sort of cover on the open sides to keep fingers and other stuff out of the gears.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on September 29, 2010, 03:38:45 PM
The price sounds good to me too.

Let us know when they might be available and when I can get my name on the list (when there's a list). 20:1 sounds good to me.

Bill, is 20:1 what you would want for indoor duration work?

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on September 29, 2010, 04:04:12 PM
The thread went quiet for a while; I thought everyone had sticker shock.

Bill, in keeping with my principles of simpication and parsimony, the stray finger of which you speak so negatively is the BRAKE. It goes on top of the third sprocket. The STOP, on the other hand is that piece of .047 wire on the back side. You just push it in until it engages a spoke. A slight CW turn of the crank disengages it with a nice audible snap. It works wizard. As for dirt, gears need protection from it, chains not so much.

I don't like making comparisons. It's not polite. That said, if you stop in mid-wind to watch a pretty girl walk by, or to order your latte, and then you go back and look at your winder, you won't need to wonder whether it's registering 1750 or 2250.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on September 29, 2010, 04:16:45 PM
Art,
I was just about to inquire about a brake. Seems like you have thought of it already. I assume that the aluminum angle on the front is the mount to attach the winder to the base after winding?

I can see it now, Art's see through high tech winder and Bill's electronic torque meter working together in unison....

Tony
-ahhhh 8)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: craig h on September 29, 2010, 07:14:08 PM
I may need to get my name on the list as well.... it's really nice!


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on September 30, 2010, 10:55:07 AM
Tony...

Go check out reply #100 on page 4. There's the whole thing set up with an earlier version of the winder. If you go back through the whole thread you'll see the original one, and then some changes that were made to address concerns about the thrust bearing (the first one had a ball thrust bearing). These "improvements" were later deleted and this last one is simpler than the first and works just as well. The thrust bearing on the current version is the nylon spacer tube against the aluminum frame with a couple of little washers in between.

The original thought was to rig something up cheap and fast to calibrate a couple of disc-and-wire meters that I had made. Then I realized that the scale is always in the field box anyway, so why not use the calibrator as the meter?

Tapio and Bill made theirs more sophisticated, but, hey, that's them. My idea was to come up with an apparatus that was quick and easy to make by anybody, using materials at hand, and that cost nothing. But, hey, that's just me. I hadn't intended it to be 1000 times more accurate and readable than the normal ones in universal use, that just happened.

A.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on September 30, 2010, 12:44:46 PM
Concerning the torque meter:

I used up all my first order of aluminum stock making mistakes. More should be coming in a few days. I'll put selling details in the For Sale section to keep from running afoul of the forum rules.

If you should decide to order one please don't expect something like Ray Harlan or Wayne Johnson would produce. My machining skills are not very good and my drill press is a cheap one from Harbor Freight that holds drills but otherwise doesn't have much to recommend it.

What I will guarantee that you get is a meter that works exceptionally well and that should be very durable.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: ykleetx on September 30, 2010, 02:12:28 PM
So I dunno, how does parts, mat'l, packaging and posting plus $50 sound? Should put it in the $110 area delivered.

I would like to get the winder without the digital counter. How much would that save from the $110 price?

-K


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on September 30, 2010, 02:24:40 PM
Why would you want a winder without a counter?

Tony
-just inquiring minds... ???


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on September 30, 2010, 03:28:19 PM
Two good questions.

Basically, all the labor is in the winder, and the counter ($32) just gets slapped on with a couple of strips of 2-faced tape, so there'd be no huge saving. Let me go back on that a little. No mounting bracket (easy to make), no sensor ($3 and just glues on w/ epoxy) and no rotor (a little labor in that one). So I dunno...$40-$45 less?

Right now I'm working on drawings for my Beta Builder. Why don't you wait for them and build your own? Part of the purpose of the design is that it can be easily fabricated by anyone who has the skills to make a model to wind with it. I'm about there now.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: ykleetx on September 30, 2010, 04:08:43 PM
Why would you want a winder without a counter?

Tony
-just inquiring minds... ???

Well, when I wind, I won't be ordering latte nor will I be looking at the pretty gals ...

And, as a personal preference, I like the look of the mechanical winder by itself.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on September 30, 2010, 04:15:52 PM
To each his own of course. I just think that at some point you will want a counter and why not get one to begin with?

I've been distracted and lost count myself. I like a counter.

Tony
-but that's just me... you're mileage may vary!


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on September 30, 2010, 04:36:13 PM
Counters become more desirable as the flier ages. Kang is too young to grasp that. Tony? He must be older than he looks!


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on September 30, 2010, 05:47:11 PM
My new supply of aluminum arrived today.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on September 30, 2010, 06:30:35 PM
If it's built to the plan, there will be room to add the rotor, sensor and counter afterwards. Or, it can be built 5/16" thinner and, as the memory starts to go, it can be widened with little cost and effort to make room for the switch and rotor. Actually, the first one I made that had a counter had those parts added on outside the frame.

I built the first ones without a counter because 1:20 isn't that hard to deal with. And (Bill, you would know better than most of us) once the pro starts to feel feedback, doesn't he switch off to the torquemeter? Or do you use them both together?

Here's this morning's project. I adapted the Cub3L to my old K&P 1:15. Works fine, for a K&P, but working with the Frazer-Nashes has spoiled me a little.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on October 01, 2010, 09:22:45 PM
I've had a couple of requests for a gm-cm version of my meter so am adding that to the offering.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on October 02, 2010, 02:06:27 AM
Can you do it with the same mechanics? Probably not?

When I was building my version, I spent some time fooling around with the different units (grams, ounces, grains etc.) trying to figure out if there were two that were related at 1:71 to each other, so that by selecting the units you could jump from g*cm to oz*in. But did not find any such combination...


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on October 02, 2010, 10:57:19 AM
Am I just too simple, or am I missing something here?

Why not make the arm a cm long rather than an inch and use the gram rather than the ounce mode on your scale?
 
Or, better yet, you could make an arm that flips over, a cm on one side and an inch on the other with a little weight on it so it would be balanced. Then change scale modes to match the arm in use. The pivot would have to be just a little higher than an inch off the deck.
 
Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Pit on October 02, 2010, 12:47:42 PM
You'd probably have to change the pressure arm coming off the torque wire to a 1 cm length to get the correct reading. Changing the scale to read out in grams is usually just a press of a button on most of the commercial scales.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on October 03, 2010, 02:34:11 AM
Pit, right to the point. I was wondering (thinking aloud) if it would be possible to construct the torque meter so that you could just "switch the scale" between g*cm and in*oz, but I suppose that would not be possible, as you would need to also change the mechanical geometry of the meter.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Pit on October 03, 2010, 05:53:11 PM
Actually, such a mod would not be too difficult. An interchangeable (or sliding) "pressure" arm and some way of adjusting the torque wire position to keep the pressure arm centered.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on October 03, 2010, 07:04:13 PM
Guys, you're making yourselves crazy. Page 3 reply 69 pic 1 shows the current version of mine before the hook was bent. Reply 71, 1st pic shows it in place. The frames are attached to the board with one screw each. Back the screw off the rear frame a quarter turn, twist the frame 45° CCW and the back end of the arm assy falls out. Pick up the tail and unthread the hook from the front frame. Replace it with a centimeter arm, reset the modes on your scale and you're back in business.
My scale doesn't need to have the arm come down exactly in the center; wherever on the tray (even on the corners) you place a test weight, it registers the same. Obviously, I don't know about yours. I guess you could mark an "X" in the center of the tray and move the scale so it aligns.

Pit's idea is good, too. You could have both arms (inch and cm) extend off the same side of the centershaft, but separated enough so the scale could be moved back and forth to engage one or the other.

I wouldn't bother with it personally, because in my country we still cling to the ancient systems. We have metric screws in all our cars, but we still torque them to footpounds. Go figure.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: frash on October 04, 2010, 10:49:55 AM
This has been an absolutely wonderful thread. Thanks to all of you. Now for a strange question, but don't let it sidetrack your current projects that you are reporting here.

More than 50 years ago, probably in the early 1950s in a model magazine or a automotive tire maker's brochure, I saw a drawing or sketch of a rubber motor for model planes or toy cars that was based in stretching a rubber motor, not twisting it. There were 2 small spools of the same diameter and geared together 3:1. (Art356A's chain drive would be good!) When the crank on the "storage" spool was turned manually, the "power" spool rotated faster to stretch the thin rubber strip. When the crank was released, the stretched rubber strip rewound loosely onto the "storage" spool and spun a prop or wheel, probably on the "storage" spool. This description is undoubtedly garbled after 50 years. Can anyone find a reference or reproduce this? Today's rubber would require a higher gear ratio, but can this actually work?

Fred Rash


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on October 04, 2010, 02:06:28 PM
Fred, think of it in terms of multi-engines.
a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on October 04, 2010, 05:31:46 PM
This is the final version. The frames can be made of any stiff material, like aluminum, Lexan, phenolic, even plywood. There's only one critical solder joint and one moderately critical dimension. It can be built with this counter for less than $75, or less than $30 with no counter.
Any reasonably equipped modeler's shop should support it (a drill press is advisable).

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on October 04, 2010, 07:18:13 PM
It's the same except I have to move the load cell to give a one cm arm. I don't know a way to make it switchable from one unit to another.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on October 04, 2010, 08:14:32 PM
Bill, how about this? A second hook shaft, 1.54" to the left of the existing one and parallel to it, with a cm long pressure arm shaped so it arches over the top of the existing one and lands in more or less the same spot on the scale tray. Use either arm and swing the unwanted one CCW out of the way. Or you could leave them both resting on the tray and zero them out that way, and then use either the inch or the cm arm as desired.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on October 05, 2010, 05:07:54 PM
Bill, how about this? A second hook shaft, 1.54" to the left of the existing one and parallel to it, with a cm long pressure arm shaped so it arches over the top of the existing one and lands in more or less the same spot on the scale tray. Use either arm and swing the unwanted one CCW out of the way. Or you could leave them both resting on the tray and zero them out that way, and then use either the inch or the cm arm as desired.

That would probably work but a dual reading meter would add complexity and cost. To me the point is that someone who wants gm-cm is not going to be interested in in-oz and vice-verse. All I have to do to offer both models is drill the load cell holes in a different location and make a shorter arm. I will probably add the alternate load cell hole locations to my drilling fixture so I can drill the 2 pieces to either spec.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on October 06, 2010, 12:59:46 AM
Agreed with Bill. All this started from me wondering, if would be possible to make the torque meter so that you could push button and select the display between g*cm and oz*in; the same way that on a scale you can select between grams and ozes. Looks like it is not possible. So it does not make sense to construct unit that does both.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on October 09, 2010, 12:41:53 PM
After a couple of false starts I've settled on FliteTork as the name for my electronic torque meter. The latest instruction sheet is attached below.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on October 13, 2010, 12:34:01 PM
I owe Bill and Tapio an apology. Sorry. My bad. I've never been really good with conversions.

Making a torque meter that reads both oz/ins and gm/cms isn't easy at all. It would be if a cm were 2.54 inches long, as I thought it was until about an hour ago. But I found out that it's only .39 inches long, and that would be a problem, wouldn't it?

Apologies again,
Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on October 13, 2010, 03:32:09 PM
No problem Art.

I'm starting a new batch of meters today. I'm drilling all of them for in-oz units. A gm-cm meter will have an extra pair of holes but they're hidden by the load cell.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on February 25, 2011, 02:35:28 AM
Returning to the subject of winders:
Art, you mention "Servo City" in one of your messages. Is it those sprockets and chain that you use in the winder? The plastic chain goes onto the sprockets that also take the metal chain?

I have been thinking about building a state-of-the-art winder for P-30, as there seems to be no good ones available commercially? My current is a home-made egg-whisker with 1:5 ratio, and it is awfully slow to use for 6 strand motors, so I have considered a ratio of 1:8 or even 1:10. As I do not know for sure what ratio would be ideal, the use of chain and sprockets would make it easy to experiment and change the ratio (with gears I'd need to move some of the axis if changing gears). I think an ideal solution might be to use 1:2 bevel gears to turn the rotation plane 90 degrees (planning similar setup as for a F1B winder), and then use chain for another 1:4 to 1:5 link. Too bad servo city does not sell bevel gears....


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on February 25, 2011, 08:46:06 AM
Tapio,
There is a superb commercially available P-30 winder:
 http://www.gizmogeezer.com/winder.htm

I have one and I like it very much. the only drawback is the 1:5 ratio which I think is too low for long P-30 motors. Apparently they are working on a 1:10 modification.

Tony


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on February 25, 2011, 09:02:51 AM
Ok, that looks good. and cheap. At 50 bucks it would be a bargain just to get the gears, even if you had to do the modification to 10:1 ratio (added 2:1 gears and reverse the winding side) yourself. Thanks for the tip!

Even then, if you need to have both the bevel and straight gears, it would make a more compact and solid design to have the 1:2 gear in the bevels and the 1:5 in straight gears...


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Pit on March 01, 2011, 11:54:08 AM
With my entry into the realm of indoor Peanuts and Pistachios, I discovered that my basic 5:1 winder was just too slow. This thread got me digging thru my junk box, turning up an old, but never used hand crank fuel pump (part of my RC "retired" stockpile). It has a pretty complex gearing, but the pump drive gear is a pressed-in 2.5mm shaft (the pump itself is simply screwed onto the gear casing).

After removing the pump, I gave the crank a full turn (silky smooth), counting 21 revs of the output shaft. A new 2.5mm shaft, a new bearing plate and thrust bearing = 21:1 new winder.

Now to build a torque meter.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on March 01, 2011, 12:21:18 PM
By the way I received a digital torque meter from Olbill recently. I can say that it is nicely made and seems to work very well. I think it's well worth the money and I recommend it to anyone that wants an accurate torque meter for indoor models.

A larger version would work well for P-30 or Coupe! ;D

Tmat


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on March 01, 2011, 12:26:51 PM
Thanks for the plug Tony. The check is in the m....... (oops)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on May 01, 2012, 05:57:17 AM
Guys,

I just completed the Chain Gang Winder...it's SUPER smooth!

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: flydean1 on May 01, 2012, 09:08:00 AM
Very out-of-the-box!!!

How about a picture of you winding a motor with it?!?

I'm trying to envision a 30gram Wakefield motor wound to near 100 oz/in torque.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on May 01, 2012, 10:16:24 AM
Sorry, Dean, we figure 6 oz/in is the limit. I can get metal chain with a .250 pitch, but the thing would be big and awkward. I'm afraid you're stuck with the
Sidewinder, which is a pretty good deal for the money anyway.

art


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on May 01, 2012, 10:26:11 AM
Very out-of-the-box!!!

How about a picture of you winding a motor with it?!?

I'm trying to envision a 30gram Wakefield motor wound to near 100 oz/in torque.

I take that as a compliment!!

I fly indoor duration and maybe will venture into peanut scale....so I guess 6 oz/in is good enough for me.

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: flydean1 on May 01, 2012, 01:51:02 PM
Oh!  Now I see, this is the indoor section. :-[ :-[

Yeah that would make my analogy a bit out of line.  It was difficult to tell the size of the winder, from the photo.  Should work just fine.  Seems similar to the Rees Scale Winder, but with chains and sprockets rather than gears.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Dave Andreski on May 01, 2012, 02:10:29 PM
Oh!  Now I see, this is the indoor section. :-[ :-[

  Seems similar to the Rees Scale Winder, but with chains and sprockets rather than gears.

NO similarity at all.
This one's a lot different.
Dave Andreski


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on May 01, 2012, 05:24:54 PM
Dean, it's 1.8 high, 3.5 wide and 1.21 thick, plus the counter and its bracket. The main thing is that there is no friction with sprockets and chain. You can let an A-6 or LPP motor wind back against the internal friction and you'll typically have only 8 or 10 turns left.
Didn't the Rees winder wind backwards, or am I thinking of something else?

Wait 'til we get flying at Lakeland, and you can come over and play with one yourself.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: flydean1 on May 01, 2012, 10:47:01 PM
The Rees winder did wind backwards.  He put an arrow on it to remind the unwary.

More power to you to fly at Lakeland.  Just my luck.  I now live in Dothan, AL! :(


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on May 04, 2012, 08:58:54 AM
Next project is a digital torque meter....here is what I have so far.

Plenty of cool ideas here in this thread....once I get it done, I'll create another thread on the build.


Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on May 24, 2012, 10:13:35 PM
Guys,

Digital Torque Meter build thread...

http://www.hippocketaeronautics.com/hpa_forum/index.php/topic,12056.0.html

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: green-man on May 25, 2012, 02:13:06 AM
It looks good shadow :)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Hepcat on May 25, 2012, 10:41:17 AM
Shadow

That is a marvellous set of pictures.  Just looking at them I feel I could make a torque meter and then common sense takes over and tells me I should be too scared even to start.  For those few people like me who can understand + and – in a sum but when it comes to electricity don’t even know if the little thingies flow from + to – or – to +,  could you please add a few words?

John


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on May 26, 2012, 01:52:22 AM
Guys,

Thanks for the compliments...pictures say a thousand words, thats the reason why I didn't write anything. Will gladly answer any questions!

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on May 27, 2012, 10:43:20 AM
I guess these make a good combo in learning about rubber.

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on May 28, 2012, 09:00:45 AM
For iPhone users,

Download iSpreadsheet, it's free! This app is Excel like and has enough columns to make the flight log as described by Ray's article in his website.
The app has 50 rows, which is good enough to enter data which then can be emailed out and read using MS-Excel, the file is CSV format.

Give it a shot!

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Pit on May 28, 2012, 09:14:46 AM
That iSpreadsheet is nice (but iDon't have an iPhone ;D).  Is there something similar/identical for Android (quick search revealed zip)?


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on May 28, 2012, 09:48:39 AM
Sorry...no idea if there are any similar app for Android!

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: rodders67 on May 29, 2012, 05:51:13 AM
While browsing Hip pocket last year I came across some pictures of a digital torque meter.  I thought that the use of a digital balance to measure the reaction force was an excellent idea. I decided to have a go at building one, but before I cut metal so to speak, I decided to discuss the idea with a couple of experienced indoor duration flyers here in the UK.   An observation was that the horizontal display made it difficult to see the readings when winding a stretched motor and  I also disliked the idea of chopping up a balance.  So my brief for the project was (1) an upright display and (2) retain the balance as a reusable item.  Finding a balance with an upright display at a reasonable price took some time online however I eventually found one.  To keep the balance in one piece I decided to construct a cantilever arrangement for the hook and the reaction arm. This arrangement allowed me to have the balance in a cradle and removable when not in use as a torque meter.  The arrangement can be seen in the attached photographs.  The reaction arm is set at 1 cm from the axis of the hook allowing, the display to directly indicate gram/centimetres of torque.  Unfortunately the ROBO balance shown, while fulfilling point (1) was unusable, as it had a long settling time.  When winding or unwinding, the lengthy time between the load being applied and the result shown, caused the display to change in large irregular steps.  Further searching provided the second balance shown. The inclined display is readable when winding a fully stretched motor and this balance reacts very quickly and has been in use now for a couple of months.  As can be seen, the cantilever arrangement is constructed from square section alloy tube, bent to support the cradle for the balance and hold the reaction arm / hook arrangement over the balance. The reaction arm / hook are supported on two small ball bearings.  I have used balances with resolutions of 0.1gms   and 0.01gms and found the 0.1 gram balance preferable, as the display on the more sensitive balance was always flickering back and forwards, even when holding the motor steady. Apart from the balance which cost £10.00 all the rest came from my left over bin.  A few parts were made using a lathe and a milling machine but I am sure that a similar arrangement could be assembled without these tools.(http://)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on May 29, 2012, 07:17:56 AM
That ROBO scale would have been the ticket if it had worked well.

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on May 29, 2012, 01:22:28 PM
The inclination of the LCD panel has been discussed previously. There is a compromise necessary between being able to read the scale at a distance and being able to read it when you are at the end of a wind. For my scales a too upright position of the LCD will make it unreadable when you are close to the end of a wind and looking almost directly down on it. For my winding style the torque reading is unimportant until I am finishing the winding. I use a proportion of the expected number of turns to gauge my distance from the stooge until maybe the last 10 or 20 percent of the wind. I'm not saying that everyone winds that way but I personally have no clue what the torque readings mean for the earlier part of the process.

As far as destroying scales go - the one I use in my torque mneters costs about $8. It is unsuitable for anything else associated with my indoor flying. The scale I use during building is a milligram scale that costs about $15. It is also modified in a way that makes it pretty much useless for anything other than indoor building. Before that I used an Acculab milligram scale that cost about $250 and is pretty much useless for weighing anything because it drifts constantly.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on August 01, 2012, 09:38:12 PM
Guys,

Here is my modified K&P with a digital counter.

The bracket is 1/8" lite-ply cut to size, counter is the OMRON H7EC, small reed switch and magnet, some lead, bolts and nuts.

The rotor is installed onto the winder's plastic bush which is connected to the output gear, I filed the tip to a small rectangular shape to get positive lock on the rotor, rest is 5minute epoxy and spider wider wrapped around for added security.

The counter has a 1kHz frequency capability and I have tried winding as fast as I could and it didn't miss a count!

I'll be converting the 15:1 K&P counter next!

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on August 01, 2012, 09:40:31 PM
More photos....

Regard


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on August 01, 2012, 10:47:25 PM
Neat work, Shadow.  I never realized that the white nub rotates with the hook shaft. I thought it was a bushing.

If you really want to test it to the limit in a totally non-real-life situation, wind a motor up tight, note the turns, zero the counter and then release the crank to run back free. See if you get the same number of turns. I do and I'm sure you will too. Your counter will handle 60,000 RPM. The reed switch will handle 1,800,000 RPM (the mfr told me 30KHz, I'm not sure I believe them). Wear asbestos gloves.
Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on August 02, 2012, 01:47:24 AM
Art,

Thanks for the compliments....it's a copy of your idea!  ;D The next is to figure a way to put in a brake.

I'm confident that it's counting accurately per its design limitations and since this winder is a bit on the 'tight' side, the test would need a thicker rubber to fully unwind, we'll see how it goes.

For the 15:1, I might just build another set of frames and use the innards of the KP winder + the rotor, I have nice 1.5mm aluminum sheets just for that.

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: RolandD6 on August 02, 2012, 07:58:48 PM
Very neat job Shadow

I have bits an pieces lying around to something similar but never get around to it although I have investigated some counters (not the OMRON H7EC) but was concerned about their maximum counting frequency. Must look again and look at sourcing an OMRON H7EC.

Fitting a brake should not be difficult but what about a built in torque meter as well  ;D ;D ;D

Paul


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on August 02, 2012, 09:06:26 PM

.....but what about a built in torque meter as well  ;D ;D ;D


Now that would make it into a cool tool now wouldn't it?  :P ;D ;D ;D As of now I'm happy with the torque meter sitting on the table!

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on August 06, 2012, 05:28:10 AM
Twins!...15 & 10 ratios.

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on August 07, 2012, 12:12:45 PM
Guys,

I need some enlightenment......as I scroll through the pictures, there is a scientific calculator on every table along with the log book, winder and torque meter. Can someone please let me know what is the scientific calculator used for?

My apologies if the above question sounds like a newbie...I am!

Thanks.

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: jakepF1D on August 07, 2012, 03:34:20 PM
I use a calculator to find the average RPM after a flight.  I also use a calculator to figure out the weight of a 1/4 motor spacer when I'm too lazy to do the math in my head.  The calculator app on my phone works fine for this simple math.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on August 08, 2012, 11:11:46 PM
I use a calculator to find the average RPM after a flight....

How?.... Wind it up, hold the model, and take RPM using a tach every 15s? then calculate average?

Thanks in advance.

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: jakepF1D on August 09, 2012, 12:50:51 AM
I put the motor back on my winding setup to count how many turns are left after a flight.  If I launch with 1600 turns and land with 100 left at 30 minutes, then my average RPM is (1600-100)/30=50.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on August 09, 2012, 06:27:53 PM
I do it the lazy person's way. I keep all my data in a spreadsheet on my HP Mini. The spreadsheet tells me what torque and turns to expect from the motor and after the flight it calculates the average rpm. The file goes into a Dropbox folder so when I turn on my Mini at home the updated file is copied to my home computer. All the data from all of my flights is available in the spreadsheet. I have a separate file for each class I fly but it could also be done on separate sheets in one file.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Ron_P on August 09, 2012, 10:41:09 PM
Bill,

Is that HP mini a calculator or a pad?


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on August 09, 2012, 11:42:18 PM
It's a netbook computer. The one I have now (Mini 1104) has pretty much all the capabilities of a regular laptop except for the 10" screen. It fits in the top of my toolbox and the battery lasts thru a whole day of flying.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on August 10, 2012, 01:19:58 AM
Another newb question....

Why do we need to know the RPM? What does it tell?

Thanks in advance!

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: mkirda on August 10, 2012, 10:30:02 AM
RPMs will give you an indication of how long a maximum flight could potentially be.
i.e. 1000 turns @ 100 RPM average = ten minutes.

With a given plane you can go thinner, pack more turns, use less pitch (higher rpm) and try for peak time.
Alternatively you could go thicker, less turns, more pitch (less RPMs) and see if it gets you higher times.
At a certain point it is all about total power, torque and propeller efficiencies for a given height ceiling.
At least in this newbie's limited understanding.

Regards.
Mike Kirda


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on August 10, 2012, 10:59:04 AM
Mike has it right. If you read my last posts in the F1L section you can see how important rpm is to reaching a goal time.

For F1D's or any other class using VP hubs the rpm's are normally taken at a number of points during the flight to gauge the rate of change of the VP. This is usually done with a stroke watch. With a stroke watch you set the watch to time a certain number of revolutions of the prop (strokes). In my case I usually use 10 revolutions which is the default setting. So you start the clock and then stop the clock on the 10th revolution. The watch calculates the rpm for you.

The stroke watch can be used on non-VP models as well since the rpm will be changing as the torque goes down. For my events about the only one where I can count the revolutions is F1M. For the others the prop is turning too fast for me to keep count and I just rely on the average rpm.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on August 16, 2012, 09:27:28 AM
Idle thoughts about winder and torquemeter hooks.

The hooks we normally see are shaped kind of like prop hooks (3/4 circle or the like) despite the fact that they deal with a very different set of challenges.

On a plane, the motor runs slack and sometimes falls off the hook, causing a CG shift which wrecks the glide. Or, the motor bunches up around the prop hook wreaking all sorts of mischief, for which we've devised the reverse-S and the Czech hook and variations.

None of this applies to winders or torque meters. Seem to me that the most effective hook shape here is a simple 110º-120º bend, with the resultant tang pointing upwards on the torquemeter and the braked/locked winder. You can remove the o-ring, Crockett hook, or what-have-you easily without breaking either your wrist or the model.

On my winders, I use a simple U-shape with the hook running back parallel to the shaft about 1/4", then bend the shaft back slightly so the pocket of the hook is lined up with the shaft axis. It's easy to slip the motor off it, but it won't come off on its own.

a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on August 18, 2012, 11:56:59 AM
I recently acquired a Wilder winder and have decided to use it instead of my Geauga winder. There were 4 problems with this plan - replacing the Wilder torque meter with a plain hook, no mounting foot, no brake and no counter on the Wilder. I've solved all of them except the brake. If anyone has any ideas about that I'd love to hear them.

One of the goals of the mods was to have them removable so that any future owner might be able to restore the winder to close to original condition.

Here are some pictures of the modifications. I found a pedometer at the grocery store for $8 and bought a reed switch at Radio Shack for about $4. I soldered wires from the reed switch to the terminals in the pedometer where the swinging weight had been located. The reed switch came with a housing that made it too big to mount under the crank. After removing the housing it was still too big so I mounted it crosswise on the winder case and glued the pedometer on top of it. This was pretty ugly so I cut a piece of plastic from the unused part of the pedometer case to cover up most of the reed switch and to strengthen the whole assembly. A small magnet on the crank closes the reed switch as it goes by and triggers the pedometer.

The mounting foot was cut from some aluminum channel and fits the mounting bracket on my winding setup. I made it to attach to one of the original case bolts. This required a slightly longer bolt but I had that on hand.

The most expensive part of the changes was replacing the Wilder torque meter that came on the winder. I bought a new shaft coupler and made a winding hook for it. The coupler cost $14 with postage.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on August 18, 2012, 01:56:05 PM
Idle thoughts about winder and torquemeter hooks.

The hooks we normally see are shaped kind of like prop hooks (3/4 circle or the like) despite the fact that they deal with a very different set of challenges.

On a plane, the motor runs slack and sometimes falls off the hook, causing a CG shift which wrecks the glide. Or, the motor bunches up around the prop hook wreaking all sorts of mischief, for which we've devised the reverse-S and the Czech hook and variations.

None of this applies to winders or torque meters. Seem to me that the most effective hook shape here is a simple 110º-120º bend, with the resultant tang pointing upwards on the torquemeter and the braked/locked winder. You can remove the o-ring, Crockett hook, or what-have-you easily without breaking either your wrist or the model.

On my winders, I use a simple U-shape with the hook running back parallel to the shaft about 1/4", then bend the shaft back slightly so the pocket of the hook is lined up with the shaft axis. It's easy to slip the motor off it, but it won't come off on its own.

a.

Art
Next time you post something like this could you do it a little sooner - like before I make a mistake? I made a round hook for my Wilder which I'm not sure I'm going to like.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on August 18, 2012, 02:07:21 PM
Art wrote to me about this sometime back and I made the mod to the hooks on all my winders soon after!  ;D

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: jakepF1D on August 20, 2012, 05:34:37 PM
I've solved all of them except the brake. If anyone has any ideas about that I'd love to hear them.

Bill,

I have what I think is a pretty nice solution for the brake on my Wilder winder.  I use a small plastic spur gear that has the same ID as the shaft coupler's OD.  It also happens to use the same size set screw so I used a long enough set screw to hold the spur gear in place while also locking the shaft.  I attached a piece of 1/32" music wire to the upper screw on the winder that is bent in such a way that light pressure allows the winder to turn freely.  If I let go of the music wire it will grab the spur gear.  The beauty of this setup is that it will allow me to continue winding hands off because it ratchets, but it won't allow the motor to unwind.  I've had fully wound LPP motors on it with no problems.

It's hard to describe completely so I'll post pictures of my winder later tonight.

Jake


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on August 20, 2012, 09:06:37 PM
Thanks Jake
That sound like a pretty easy solution. I've made a brake from a wedge of rubber that slides under the output shaft and holds it by friction. I'm going to try it this weekend. If I don't like it I'll be looking at what you've suggested.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: jakepF1D on August 21, 2012, 02:33:39 AM
Here are a few pictures of my setup.  I'm not sure where I got the gear, but it shouldn't be too hard to find one that will work.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on August 21, 2012, 07:18:43 AM
That looks good Jake. That's a really slick looking mounting foot. Is that from Wilder or did you make it?

Here is my rubber brake that I cobbled up when I should have been working. It's attached to the mounting bracket with 2 screws thru a slot in the bottom of the plate. Pushing it to the left (right in the picture) lets the shaft turn freely. Pushing it to the right locks the shaft by friction. The torque from a wound motor pulls the wedge shaped block tighter under the shaft (theoretically - I haven't tested it with a motor yet). Of course one drawback is that I need my table for the system to work, but I drive to most competitions anyway.

The winder looks "upside down" b/c I need for the output shaft to line up with my digital torque meter.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on August 21, 2012, 10:08:21 AM
I was thinking about a ratcheting stop, but couldn't figure out anything that wouldn't affect the motor feedback.

Bill, do you feed your counter with crank or hook turns? Most converted pedometers or calculators can't handle hook speed, which can run to 60Hz, although nobody ever actually winds that fast.

Shadow and I discussed the possibility of remoting the torquemeter readout to the winder. I was thinking of a light cable running a little longer than you ever stretch the motor out (wireless would be preposterous). He felt that the voltage drop would mess up the readings. I'm not very electronical, so I'm not qualified to render an opinion on that.

A.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: jakepF1D on August 21, 2012, 11:29:06 AM
Bill, I made the foot from some angle aluminum.  I cut it to a shape that centers the output shaft on my winding stooge.

Art, I only use the ratchet feature on mine when I'm adding the last few turns.  It works really well for that.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Pit on August 21, 2012, 11:35:19 AM
You're already hobbled with a low voltage, so any wire running more than three feet would have to be quite hefty.  A thin wire (electronically) acts like a choke, so you want the thickest practical x-section for...don't know the max distance for stretched indoor motors.

There ARE tables that list cable/wire resistance and voltage drop/x-distance.  Shadow might know where to look.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on August 21, 2012, 11:37:06 AM
Wireless is not preposterous. In fact it's super cool! 8) ;D

Tony
-come on Art, you know you want to ...


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: jakepF1D on August 21, 2012, 12:02:56 PM
Shadow and I discussed the possibility of remoting the torquemeter readout to the winder.

I'm not sure I understand why this would have any value.  Torque readings will fluctuate wildly during winding based on how far you have the motor stretched.  I don't pay any attention to torque until after I've hooked my winder base into my stooge where the proper hook to hook distance is achieved.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on August 21, 2012, 01:13:59 PM

Bill, do you feed your counter with crank or hook turns? Most converted pedometers or calculators can't handle hook speed, which can run to 60Hz, although nobody ever actually winds that fast.


I measure crank turns. I think in crank turns also and all my data is in crank turns.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on August 22, 2012, 08:32:27 PM
Wireless is not preposterous. In fact it's super cool! 8) ;D

Tony
-come on Art, you know you want to ...

Yeah, I think if it could be made wireless, it will be totally cool....however the cost would be unjustifiable. I have used the digital torque meter and the LCD is bright and it's easily read, even from 10-12 ft away.

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Dave Andreski on October 18, 2012, 10:16:14 AM
You're welcome!
Glad you've found a new perspective.
Dave Andreski


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: rogermorrell on October 18, 2012, 11:54:43 AM
While not indoor .... for whatever it's worth Rene Limberger did a very custom winder counter and torque meter that displays wirelessly on to an i-phone [naturally because it's Rene] for Igor Zilberg, a German F1B flyer. Zilberg had extra requirements with respect to other F1B flyer because he has some models with very long, for F1B, motor runs. I think he uses a 10 to 1 winder. There was an issue of counting fast enough.

Roger Morrell


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on October 18, 2012, 12:36:32 PM
I hear about that Roger. Very cool. But how does one look at the results on an Iphone while one is furiously winding? Was the Iphone mounted to the winder? Or to the stooge?

Tony
-inquiring minds.... ;)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: rogermorrell on October 18, 2012, 03:16:26 PM
Rene just built it - not sure where Igor put it, probably on the winder .  - Wait for the Magic Modelsport one, we are going for a heads up display or maybe audio output  ,.... :-). 

BTW I think he was going to use it for some kind of motor testing too.  What surprised me was that Rene said there was some difficulty in counting the turns.  I'm not sure why, it was partly to do with the 10:1 that Zilberg uses so is different from any other F1B flyer.  I have built an anenometer for Hot Magic Mk2 that counts quit high rpms so it should not be a major problem. Probably need to use Hall effect switches.

The Torque part is on my to do list.  The Malkhaysians made a stooge torgue meter for winding tube similar to the ones made years ago by Bob Wilder except they used a digital scale to show the reading. It works OK but is hard to read and the scale turns it self off at inconvenient moments.  Grandson Wes has one but we need to practice more with it. I think Rene used a load cell with a precision rotary encoder to measure the torque.  I was thinking of a large , bright LED readout that could be read from a distance while winding. Failing that it would put a radio driven readout on the winder.  I have done soem radio stuff like that already.  I would not do an i-phone because of the commerical difficulties in working with Apple.



Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on October 18, 2012, 03:33:33 PM
FWIW, the counter I use will take 10K Hz, and the $4 reed switch 60K Hz according to the manufacturers. That last sounds a little outlandish to me, but it's also irrelevant. So Hall effect sensor technology might not be necessary.

a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on November 03, 2012, 11:06:42 PM
Digital Torque Meter inside Chain Gang Winder - Concept / Theory

Guys,

This is an idea (credit to my flying buddies who contributed to the concept), please study the pictures....here is how it should work.

To wind rubber, the plunger (black bolt) is pushed, this moves the torque arm disengaging it from the output shaft. To get the torque reading after the wind or in between, letting go of the plunger engages the torque arm to the output shaft. The torque arm will then press against the load cell (black colored block at the bottom of the winder). The LCD read out can be fastened to the top of the counter. The torque arm here doubles as breaks.

If the counter's rotor is longer, this can be used as a torque arm too!

To get this working properly, there are a few things that needs to be ironed out but I'd like to hear comments.

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on November 05, 2012, 03:01:22 AM
For indoor winding, I like to torque meter that can be read all the time, so that I can follow the torque while winding in the final turns. As a matter of fact, I would like to have such unit for outdoor (F1B) winding too, there I currently have the twisting-piano-wire -torque meter between the winder and the rubber, so that I need to stop winding to read the torque. I have been thinking (for years!) if the torque could be read somehow from e.g. sideways load on the prop shaft, but obviously there are considerable complications with the sideways loads during the winding. Anyway, somehow the torque is affecting the sideloads on the winder shaft bearings, right?

 


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on November 05, 2012, 03:52:26 AM
I rely on the number of counts to bring the rubber to its max instead of torque and use torque for launch.  Is using the torque to determine the max winds rubber better than using counts? does it matter? (I'm still learning)

With the way the concept winder is done, there is no way in getting continous reading of the torque.

Also, is the torque reading on the winder really needed? Worth the extra effort/cost? Any real advantage over the one the table?


Regards




Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: jakepF1D on November 05, 2012, 12:22:10 PM
I have two goals in mind when I'm winding; torque and turns.  In my mind torque is completely irrelevant until the motor is at the proper hook to hook distance.  When the motor is stretched you can change the torque reading dramatically just by moving in and out.  So for me I focus on turns until I clip my winder to my stooge.  That's when I achieve proper hook to hook distance and I begin paying attention to torque.  I've never felt like knowing the torque midway through a wind had any value.  That's just my opinion and others may disagree.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on November 05, 2012, 02:14:23 PM
Shadow, we have to pay attention to people like Tapio and Jake, because they know, and we don't. At least I don't. Not yet, anyway.

Right now, here's my thinking. I've thinned the winder down to a hair under 1.1", enabling me to use stock hardware rather than make my own thru bolts. This looks like it adds another bay to the unit, which adds another frame, six more spacers, a new configuration hook shaft, and probably juggling the hookshaft bushings. And having to shop-build all the screws again. Nothing insurmountable, but is it worth the effort and expense?

It's like the autosubtract I'm working on. No idea what it would cost once it's finally working reliably, and would it be worth it to anyone? I'm starting to doubt it.

 art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: PeeTee on November 05, 2012, 02:58:35 PM
Quote
I like to torque meter that can be read all the time, so that I can follow the torque while winding in the final turns. As a matter of fact, I would like to have such unit for outdoor (F1B) winding too

Tapio

A couple of years ago at Poitou, I saw what appears to be a torque meter built into the stooge, but wasn't able to speak with the owner to find out how it operated. I did take a couple of photos though which may give you food for thought. I assume it's based on a spring or coiled wire as per the Eastern European winders, but I'm sure you can figure something out.

Sorry for going outdoors on the indoor topic ;)

Cheers

Peter


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tmat on November 05, 2012, 03:40:53 PM
Bob White and Walt Ghio used to have stooged mounted torque meters used when winding their Wakefields. I recently saw Evgeny Gorban with a stooge mounted torque meter and even more recently Carrol Allen. Now that almost all F1B flyers wing outside of the model (except Tapio!) using the ubiquitous half tube system, a stooge mounted torque meter is quite practical I think. In fact I'd much rather have the torque meter mounted on the stooge than on the winder, even if I didn't have to stop the winder to look at the torque (as I do now). I would not even look at the winder until I was right at the end of the winding process.

Tmat
-ok back to indoor winders/torque meters  ;D


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: duration on November 05, 2012, 05:07:56 PM
At the 2011 US Nats, Sevak Malkhasyan was using an interesting stooge-mounted torque meter. The half-tube locked into a pivoting fitting mounted on the stooge. An arm projected out and was connected via a short cable to a digital pull scale. Only problem might be difficulty in reading due to glare on the scale. I think I have a photo somewhere and will try to dig it up.

Related to all this, I have finally figured out a way to carry all the ground support equipment for F1B/F1G.  It's a tactical short double gun case from Drago Gear. Item # 12-301BL. I ordered it from cheaperthendirt.com, about $80.

The case measures about 12 x 36 inches and has a large divided center compartment designed to carry two short rifles, or, in my case, two stooges, winder, thermister pole, etc. There are large pockets on one side and shoulder straps on the other. This is mil.spec swat team gear made from ballistic nylon, so it should hold up. I got mine in black to match my model box cover. But they also have a tan color. Should better the the assorted cardboard boxes and mailing tubes I have been using.

Louis


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: duration on November 05, 2012, 05:34:41 PM
Here is the photo of the Malkhasyan stooge-mounted torque meter. The half tube attaches to the turned aluminum cylinder at top, held in place with a pin. The cylinder is free to rotate under torque (probably ball bearings involved). As it rotates it plus the strap attached to the digital pull scale. A cable at the other end of the pull scale is attached to the stooge by a cable. This is the cable that is normally used to apply load to scale.

Perhaps it could be scaled down for indoor use.

Louis


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on November 05, 2012, 07:08:57 PM
Elegantly simple.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on November 05, 2012, 07:16:00 PM
I have two goals in mind when I'm winding; torque and turns.  In my mind torque is completely irrelevant until the motor is at the proper hook to hook distance.  When the motor is stretched you can change the torque reading dramatically just by moving in and out.  So for me I focus on turns until I clip my winder to my stooge.  That's when I achieve proper hook to hook distance and I begin paying attention to torque.  I've never felt like knowing the torque midway through a wind had any value.  That's just my opinion and others may disagree.

I agree with Jake - at least about 95%. I start worrying about torque when I'm approaching the end of winding. Several people have commented that they can't read the FliteTork meter when the motor is stretched out. I'm not sure what information they're looking for. When Kang was a "beginner" he told me I always watched my torque meter while winding. I told him it was just a habit. The only thing useful about doing that is that it might keep someone from asking you a question while you're winding.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on November 05, 2012, 08:56:10 PM
This looks like it adds another bay to the unit, which adds another frame, six more spacers, a new configuration hook shaft, and probably juggling the hookshaft bushings. And having to shop-build all the screws again. Nothing insurmountable, but is it worth the effort and expense?
 art.

Actually, the setup can be installed outside on the left side of the winder, the load cell can be placed on the shoe of the winder, but the parts will be exposed however the process of disengaging the torque arm is made easy by placing it outside and since the torque arm works as a brake, it's doing 2 jobs at the same time.

I have ordered the smallest 100g scale that I can get from goodluckbuy.com, I'll 'retro' fit the bits on to the stock CGW and post pictures / video for comments.

As to whether it's worth or not....well, it depends on the users on what they want and what they are will to pay for such convenience!

The autosubract is a very usefull convenience which I don't mind paying for...as it helps to concentrate in winding instead of remembering to flip a switch if in case you forget it really messes up the counting especially if you are trying to get to the launch torque by backing off and up winding a few times!

Regards




Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on November 05, 2012, 09:20:27 PM
On a seperate note, I recently got a mechanical counter which subtracts when reversed, seems to be the right size....will be fun trying to install this in a winder.

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Tapio Linkosalo on November 06, 2012, 02:37:12 AM
Now that almost all F1B flyers wing outside of the model (except Tapio!) using the ubiquitous half tube system, a stooge mounted torque meter is quite practical I think.

Yeah, I'm working in that direction, already have a half tube and some back bobbins. However, decided to try to system on a P-30 first, and have found inserting the back bobbin in a reliable way not so easy... have gotten the full-wound motor on my hands on a couple of occasions. This is ok with P-30, but would be quite scary for F1B, so I still have some reservations on the system...

But agreed, a stooge-attached torque meter would be practical when winding the motor outside the model. Less so, if the meter would measure how the wind is rocking the model....


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on November 06, 2012, 01:59:53 PM
On a seperate note, I recently got a mechanical counter which subtracts when reversed, seems to be the right size....will be fun trying to install this in a winder.

Regards

Where'd you get that ???? Does it click over or is it nice and smooth? If it's smooth it can save me a ton of time and money.

Art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on November 06, 2012, 08:58:31 PM
Art,

I bought it from ebay, US seller...the counter is made in England. I'll post more picture soon. It turns smooth, doesn't click and resets nicely.

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: ykleetx on November 08, 2012, 06:55:47 PM
I have two goals in mind when I'm winding; torque and turns.  In my mind torque is completely irrelevant until the motor is at the proper hook to hook distance.  When the motor is stretched you can change the torque reading dramatically just by moving in and out.  So for me I focus on turns until I clip my winder to my stooge.  That's when I achieve proper hook to hook distance and I begin paying attention to torque.  I've never felt like knowing the torque midway through a wind had any value.  That's just my opinion and others may disagree.

I agree with Jake - at least about 95%. I start worrying about torque when I'm approaching the end of winding. Several people have commented that they can't read the FliteTork meter when the motor is stretched out. I'm not sure what information they're looking for. When Kang was a "beginner" he told me I always watched my torque meter while winding. I told him it was just a habit. The only thing useful about doing that is that it might keep someone from asking you a question while you're winding.

Stan Chilton wrote a well known article on how he winds.  He looks at torque pretty much the whole time while he winds.  His article is here:

http://www.indoorduration.com/INAVWinding.htm

I don't wind this way, but I look at torque during the second half of winding.  I pay close attention after reaching 50% of peak torque, when the motor length is still stretched to about 1.5 to 2X.

-Kang



Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: ram on February 19, 2013, 12:16:41 PM
Spent a few hours this weekend putting together some field equipment. It uses Arts winder and Olbill's torque meter. Wasn't sure how long a hook to hook distance I needed. I made it extra long, just in case.

 Rey


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: tross on February 19, 2013, 12:23:14 PM
Wow! :)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: ram on February 19, 2013, 03:59:04 PM
Thanks, tross!

As a followup, what information should I include in a flight log?  I did a few searches and didn't locate what I was looking for. I did see where Olbill mentioned using a netbook.  I'm planning on flying primarily the non-scale events. ...if that makes a difference.   So far I've built a parlormite and an EZB for practice.  Both are paper covered.  Next up is a LPP covered in film.


Rey


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on February 19, 2013, 07:52:51 PM
Here 'tis.

http://www.indoorspecialties.com/index1.html

Click "articles" on the left, and the flight log is the last selection.

Requires rather more discipline required than I can muster, and as a wise man once said, indoor is all about recordkeeping.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on February 19, 2013, 09:58:38 PM
As a followup, what information should I include in a flight log?
Rey

Here is a screen shot of my Excel spreadsheet. The calculations for max turns and max torque are below:

Formula for max turns (Wtmax):

=45.67*H70*SQRT(1/G70/J70)/20

H70 is the motor length
G70 is the number of strand in the motor
J70 is the grams/inch for each strand
20 is the gear ratio for the winder

Formula for max torgue (Qmax)

=((I70/H70)/0.11)^1.5

I70 is the motor weight
H70 is the motor length

(couldn't resist copying a good one!)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: ram on February 20, 2013, 09:54:16 AM
Thanks Art and Olbill!

Is there any benefit to adding temperature and time of day to the logs?

Oh, and what is prop type on Olbill's spreadsheet?

Rey


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on February 20, 2013, 10:47:03 AM
The prop type is just any kind of identifying nomenclature that makes sense to you. At USIC 2007 I had 2 F1L's - #1 and #2. I also had 2 props - #1 and #2. So 1/1 meant prop 1 on model 1.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: ram on February 20, 2013, 11:45:05 AM
The prop type is just any kind of identifying nomenclature that makes sense to you. At USIC 2007 I had 2 F1L's - #1 and #2. I also had 2 props - #1 and #2. So 1/1 meant prop 1 on model 1.

That makes sense.

What does your motor weight include?  Lube, sleeves, o-rings, etc.? Or, is it a recorded weight before you've lubed and tied?

Rey


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on February 20, 2013, 01:59:34 PM
Kang has given me a bunch of grief about this but my weight is for a ready to use motor with o-rings, lube and sleeves (for some events). It would be more accurate to use the bare rubber weight. I may start doing it that way in the future.

Another somewhat controversial thing is what rubber length you use for the calculation. A new, never wound motor will give one set of numbers. So should you go by that set of numbers for all future uses of that motor? I don't think so but that is just my opinion. The more the motor has been wound and the timing of those windings will make a used motor longer than it was when new. John Kagan has said that in his opinion a broken-in motor is just a motor that is longer than it was when first made. I agree with this thinking. I'm not sure that it is 100% correct but I think that it is at least close to the truth. So now, unless I am extremely rushed (or just lazy) I will plug in the actual motor length before I wind.

I use a netbook computer b/c it fits in my tool box and it runs all Windows programs - the chief one of interest being Excel. The recent ultrabook computers with 11.1" screens might also be good and compact but are pricey. A tablet that runs Excel without problems might also be a good choice. There's nothing secret or complicated about my Excel program so I would be happy to share it with anyone who needed it.

Another point is that all my flight data is stored in a Dropbox folder. Anytime I add to one of the files it is automatically updated for all my computers and my phone and so is available wherever I might be.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: ram on February 22, 2013, 01:35:14 PM
Thanks, Bill.  Great information for me.  I'm going to try weighing without o-rings and sleeves.  It will be interesting to see how it affects the max torque calculation's accuracy in your spreadsheet.

Rey


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on March 02, 2013, 11:37:45 AM
Further thoughts on hook shape...

I went back and reread #238 on page 10, and saw that where I had recommended a simple 110º bend for a torquemeter hook, I had also written something about using it on a winder, as well. But I never actually did it until a couple of days ago. It's really easy to use compared to a normal hook. The foto shows it in the up position, but if there's any tension on the motor at all, it doesn't need to be. With the prong pointing up it's easier to unload, though.

I think I'll make all the winders like this from now on. I'll leave the shaft a little long, in case the user wants to reshape the hook into a more traditional style. Some guys are old and set in their ways and lock themselves into counterproductive traditions. But folks like that are unlikely to buy a modern winder anyway.

a.  


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: applehoney on March 02, 2013, 07:48:37 PM
>Some guys are old and set in their ways and lock themselves into counterproductive traditions.

Eh?  What ... ?  Who  ??!    Nah ....   not me.


Well, maybe ....


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: spacerod on March 02, 2013, 09:24:39 PM
Art
 Great idea . I think I'll convert my winder and torque meter. I always have trouble
getting a wound motor off the round hooks.

Charlie Coeyman


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on March 03, 2013, 11:04:58 PM
Not to be a wet blanket but I have a little problem with the hook as pictured. On a torque meter it wouldn't be a problem but on a winder I would want to make sure that the o-ring was seated in line with the shaft of the winder to keep from having a lot of vibration during winding.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on March 04, 2013, 12:29:10 AM
Nah, it don't happen. I was thinking of that too, so I paid a lot of attention to it while winding, and I couldn't provoke anything like that. Maybe with a big heavy motor stretched out far and wound really fast, so it would whip and flail around. Nobody winds like that, do they?

Remember also, that this winder is a very old one. It has an .063 shaft with an .032 hook cobbled onto it. If there's going to be any runout that would cause vibration, it would happen on this one. The current winders have an .032 shaft all the way out (usually 1.5") and they're so flexible that they'd be self-aligning.

a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on March 04, 2013, 12:26:32 PM
It happens to me frequently if I don't get the o-ring on the hook straight.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on March 04, 2013, 12:28:49 PM
Here's a little lab work, using a current model winder. First, I took out the slight bend in the shaft that lines up the pocket of the hook with the shaft axis and bent it back the wrong way a little. Now we have the condition Bill was describing, but with many times the runout that we'd ever see in my original 110º straight-prong hook.

The second pic is at full blast released windback. 1000 turns in a couple of seconds. Now we can see how the centrifugal force from the whipping motor pulls the hook further off center. I can't see this as a valid problem for us, as the maximum speed we can wind with a 1-20 winder is 60 turns per second at the hook, and that's really cranking up a storm. At that speed, things are truly hopping around, but none of it is from the tiny bit of runout at the hook. What I thought might be a self-centering action from motor tension doesn't happen with a 1 1/2" hook shaft length. Oh, well, maybe with another inch or so it might. I don't think it matters.

The new winders are 25 grams lighter, all of it off the counter module, so they would be more sensitive to any vibration generated near the front end, as the mass to damp it has been reduced. But I can't feel vibes at anything like normal winding speeds, and normal for me is faster than normal for guys like Bill. Rotational vibration has many factors feeding it, the biggie being shaft speed, and we just don't reach those speeds in normal usage.

Still, the hook shape will be an option, and can always be changed by the user.

a.



 


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: _shadow_ on March 14, 2013, 03:21:23 AM
This is the shape of the hook on my CGW done after advise from Art356A.

Regards


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Ding on March 18, 2013, 09:18:05 PM
I always wondered about this thought.  Would the dynamic torque be the same from either end of the motor both for winding and for energy release? Hmm!!  :-\


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on March 18, 2013, 11:47:55 PM
Yes.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on March 18, 2013, 11:55:05 PM
The motor is just a mindless column of twist, held captive on both ends. It doesn't know which end is attached to the prop and which to the airframe. It'll unload into the hook of least resistance. If you hooked one up to a torquemeter on both ends the readings would match.

IMHO

a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Ding on March 19, 2013, 02:22:53 AM
I dunno but when I wind with the torque meter at the other end opposite the winding end the pointer is never steady. Doesn't that indicate some degree of variation?  Am of the belief that if the pointer waddles one way the other end might waddle the other way but not necessarily at the same time.  Could it be that the torsion in the MW is not also behaving linearly?
But I agree that on the average the torque by the rubber motor should normalize smoothly.  Hence a smooth RPM.
Ding :D


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: MikeM on July 21, 2013, 12:24:46 PM
DISREGARD....i found this thread by Google search and didn't realize it was in the indoor section.........i'll post where it needs to be.



probably a common sense question here, but i am not one to be different other than i am making my own stooge with materials on hand.

in the picture i drew an arrow from ground to bottom of stooge (no this one is not mine)...........is there a correct height or common height?

and what is it?
(http://images.rcuniverse.com/forum/upfiles/325061/Sq47133.jpg)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: FLYACE1946 on July 23, 2013, 02:16:41 PM
 the base is up the pole around 35 inches. I am 5 feet 8 and 35 inches seems just fine.

Hope this helps.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on April 08, 2014, 12:39:33 PM
Ascent of the Chain Gang.

There aren't many of us, maybe 30 or 40, but we're elite.

Joshua Finn picked up the AMA Record F1D Category I record on Feb 22, with a 28:17 flight.

Kang Lee is the 2014 World Champ by a 50 second margin at Slonic, Romania. 


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Bredehoft on April 13, 2014, 12:40:15 PM
Here are two torque meters I made to fit onto my venerable Wilder 10:1 winder. 

--george

(http://volareproducts.com/wp-content/uploads/TorqueMeters.jpg)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: aramS on August 22, 2014, 04:05:36 PM
Looking for a 120 inch-oz. Wilder torque meter. If you happen to have one gathering dust on a shelf or in the attic, it's an opportunity to find it a new home.
Also, someone has started replicating them, but my leads went cold.
Thanks,
Aram


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: mkirda on August 23, 2014, 08:44:42 AM
Looking for a 120 inch-oz. Wilder torque meter. If you happen to have one gathering dust on a shelf or in the attic, it's an opportunity to find it a new home.
Also, someone has started replicating them, but my leads went cold.
Thanks,
Aram

Dennis Tyson started making ones very similar to these.
I asked him to make me one to 120 in-oz too. He hasn't shipped it yet.

Regards.
Mike Kirda


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Bredehoft on August 23, 2014, 09:11:41 AM
Aram,

I talked to Dennis Tyson last night and gave him your number.  He said he will call you.

--george


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: aramS on August 24, 2014, 11:38:16 AM
George and Mike,
Thanks for your help. Dennis got back to me and said he will be making a new torque meter that will measure up to 140 inch oz. perfect for F1Bs.
Aram


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: USch on December 08, 2014, 12:37:01 PM
Thanks folks  ;D ;D ;D
After an evening reading 13 pages about electronic torque meters I gathered enough info's to build my own winding stooge with incorporated torque meter.
Another happy reader !!! Will post pic's as soon as possible,

Urs


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: rick121x on December 08, 2014, 04:59:12 PM
I dunno but when I wind with the torque meter at the other end opposite the winding end the pointer is never steady. Doesn't that indicate some degree of variation?  Am of the belief that if the pointer waddles one way the other end might waddle the other way but not necessarily at the same time.  Could it be that the torsion in the MW is not also behaving linearly?
But I agree that on the average the torque by the rubber motor should normalize smoothly.  Hence a smooth RPM.
Ding :D

When I first started with torque meters at the tail end of the motor, I too had the "waddling" pointer syndrome. I found that the waddle had to do with the apex of the rubber hook being not on center-line with the torque tube or on center-line with the bearing axis on a electronic scale setup. Once I took care of that alignment, no more "waddling". My gage and/or meter readings are smooth as silk.  

These days I use a gram scale exclusively.

And my winder fits nicely to the winder frame, so that I can view motor torque relaxation, with unwinding, with time, or with massage of the knots. http://www.hippocketaeronautics.com/hpa_forum/index.php?topic=13705.msg100636#msg100636 (http://www.hippocketaeronautics.com/hpa_forum/index.php?topic=13705.msg100636#msg100636)

Richard Ranney


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: USch on December 11, 2014, 04:53:35 PM
Here my work of the last week. The mechanics of the torque-balance is build into a U shaped bracket and a ground shaft runs in 2 ballbearings. Actually I made a fork to hold the model at the rear peg...but... trying the setup at home I realized that even a very small disalignment between the model and the shaft affects the output reading heavily. So actually it is of no real use other than having just a rough idee what happens. Different if used to measure only the rubber attached to the balance with a hook instead of the fork. I can get repeatable results. The alignment is always guaranteed, at least if the hook is well centered to the shaft.
I build a small 4 pin connector into the display housing to separate the mechanics from the display.
So winding the rubber already installed in the model needs some further thinking. The model would need to be precisely guided to hold aligned with the torque-meter, especially at the point of the rear peg!

Question: exist a way to determine what max. torque can deliver say 1mm2 of rubber, of course there is a difference between a batch and another. But just to have a starting point. Or due I have to destroy some motors to know the final torque?

Urs


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: glue_finger on January 13, 2015, 09:09:39 AM
Question: exist a way to determine what max. torque can deliver say 1mm2 of rubber, of course there is a difference between a batch and another. But just to have a starting point. Or due I have to destroy some motors to know the final torque?

Urs

I did see something about an excel sheet somewhere.  I'll see if I can dig it up.  

Wow, USch, that is a pretty cool gizmo!  I think I understand what you mean about misalignments.  Even with normal torque wrenches, extensions or anything that causes the transmission of force to be less than straight and center makes a difference.  

I have started making the kind of digital meter that rick made.  The problem with that, which you are apparently trying to solve, is that it's a little bit of a process for full fuse models...  Remove the motor, wind to torque spec, reinstall motor...  that last step is proving the most troublesome for me.  I made a stuffing stick, but sometimes there is little room to get the rear peg through the tightly bunched rear loops, so I miss and the whole thing unwinds back there.  ;D  Perhaps I need to start using rear hooks?  I'm afraid of what might happen to the model if a metal hook gets loose in there.   :o

It would be nice to have a meter in-line between the winder and the motor, so that the motor can stay in the model.  

EDIT TO ADD: 

Here are some discussions of formulae to figure your breaking points.

http://www.rcgroups.com/forums/showthread.php?t=2273277&page=2

http://www.pensacolafreeflight.org/page5/assets/RubberMotorGettingMax.pdf


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Pit on January 13, 2015, 09:31:31 AM
Neat set-up, Urs!  How is the accuracy affected with the wheels of the RIVETS resting on the table?  Or is the fuselage bottom resting on a fulcrum?


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: flydean1 on January 13, 2015, 09:47:10 AM
USch,
Your setup, while a handful on a fuselage model, should work well when winding outside the fuselage using a half-tube arrangement like Coupe, Wakefield, Open Rubber type models.

Alternatively, a winding tube made of sturdy aluminum which could take the strain of a wound motor, could be held by a yoke or cradle to keep it precisely aligned with the holding fixture.  A relatively large diameter rear tube could be slipped inside to be engaged by a smaller diameter cross tube.  This tube-in-a-tube method also resists rubber bunching at the rear of the model.

You are on track to eventual success.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: USch on January 13, 2015, 10:20:05 AM
glue_finger,
the excel I found later in the plan gallery made by frash, it gives you max. turns and torque. For us european a little nasty but very helpful to have a starting point. I tryed to convert everthing into cm and g, but thats not my business.

Pit,
the wheels were the first stalling point. I put a polistirene block under the belly so the fuselage could rock and roll around on it. But the fuselage will never stay aligned with the torque-meters shaft and this alters heavely the output.

flydean1,
the Rivets has an inbuild error (as I wrote somwhere else even the big's can make errors). The rear peg is to far aft. That gives a lot of trouble when changing motor with different weights and does not allow to wind outside the model. I had to build my own burst tube to reach the peg without hampering the formers. Moving the peg one bay further would solve the problem, but there are the letterings and who wants to destroy them  >:(
But you make me hope that I have not to throw away everything  ;D

On the next P'nut I have a lot of details to improve  ;)

Urs


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: glue_finger on January 14, 2015, 01:12:28 AM
Made a really field expedient type  :D analogue torque meter just to get a hands on feel for the concept.  I think the wire is .032", about 8 3/4" length.  The masking tape pointer only deflected about 20o before a single strand failure occurred in the 4 strand 3/32" motor.  Guess it would need a longer piece or thinner piece to deflect more.  Would a longer piece of the same gauge deflect more?  Anyway, the wire is held static to one end of the tube with rubber tape.  The foam dial is glued on with Elmers.   ;D  The good feature in my view is it could just hook between the prop hook and the winder and give a reading without removing the motor.  I guess you would want a blast tube in that case.  It would be necessary to stop winding and take frequent readings when it's getting close to failure since the dial spins while winding.  That should not be too hard to remember.  I'm starting to get a feel for when these small motors are about to blow out anyway, so it won't be too off-putting.  

Also shown is the torque arm and bearing for the digital scale type meter.  It's still waiting for a nice piece of lumber to call home.

Baby steps.  






Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: glue_finger on February 08, 2015, 09:26:44 PM
More work on the digital and analogue meters.  I used an equation to relate torque, angle theta, wire length and diameter.  I made a wire twist meter to try to show one inch ounce at 270 degrees deflection.  Then I coupled it to my digital meter in development, and torque of about one inch ounce shows on the twist meter when the arm on the digital meter is about one inch long.  So far, so good.  Next, I destroyed two 1/8" two strand motors.  One broke at a little less than 1 inch ounce and one a little more according to the wire twist meter.  

Does anyone know if that is approximately correct?  Would a two strand 1/8" motor break at about one inch ounce of torque?  


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on February 08, 2015, 11:38:27 PM
A 1/8" motor made from Tan 2 rubber should take close to 2 in-oz. From Tan SS it should take considerably more.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: glue_finger on February 09, 2015, 12:07:10 AM
Wow, so way off then.  This is Tan SS.  One loop broke at about 1.4 in oz, according to the digital readout, that was the highest.  Is it possible that a .020 wire hook is cutting the wire ahead of schedule? 


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: rick121x on February 09, 2015, 11:00:03 AM
Just a thought: Have you calibrated your torque meter with a known weight at a specific distance?

Richard Ranney


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: glue_finger on February 10, 2015, 12:27:04 AM
I just did, since you suggested it.  Seems like the next logical step.  Who knows how much measurement error and experimental error is involved?  Anyway, I think it is closer to calibrated now than it was.  After hanging some weights from the rig shown, then setting the digital meter from the twist meter, the slider on the torque arm of the digital meter is about 31/32" from center of the pivot shaft.  I used lead weights in .25 oz increments to hang off of the wire twist meter at 1 inch from center to calibrate. 

I now find that the 1/8 motor bursts at about 1.8 in oz as measured on both meters.  They agree pretty well. 

These are new motors, not broken in at all.  Not sure if that would have them bursting a bit early? 



Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: glue_finger on February 12, 2015, 11:44:06 AM
I think this must be pretty straight now...  There is another equation to describe a wire torsion meter that includes coefficients for ranges of wire diameter.  When tallied by this equation, the physical pendant weight calibration matched to within 2 degrees of the theoretical angle of deflection.  I measured 240o deflection at 1 in oz and then calculated 238o.  This also matches with the readout of the digital meter with arm length at 31/32".  So, two physical methods in agreement with a calculated value.  I bet this is reasonably close  :)

Here is the source for that equation...  http://www.gryffinaero.com/models/ffpages/tools/torque/torquetech.html#calib (http://www.gryffinaero.com/models/ffpages/tools/torque/torquetech.html#calib)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on March 12, 2015, 10:39:34 AM
A question for the Chain Gang: Does anyone use the subtract count switch when doing a windback? I incorporated it because the counter has a subtract capability, so the switch makes it accessible. I'm thinking now that most fliers count back by zeroing the counter at peak winds and then getting a down count. If that's the case, then the toggle switch is just a distraction and can be dispensed with. I hope.

art.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: ykleetx on March 12, 2015, 11:41:50 AM
Art,

I never use the subtract function.  Thanks.

-Kang


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: tstone on July 13, 2016, 05:31:44 PM
I must have missed it but does anyone have a link to wire size & dial face for making an 0-.1 oz indoor torque meter?


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Rossclements on December 30, 2016, 11:32:36 AM
Is there a set wire length from the 90 degree bend to the scale its self? I have decided its time to make a torque meter, but I would like to use a standard scale as I fly everything from mini sticks to planes using 3/32 rubber and would like to not have to make 3 different torque meters. I am going to an event late January to fly primarily A-6, I made a flight earlier that broke the junior cat 1 national record without a torque meter and want one to get more consistent times as I am going to the same place to try and make some official flights.


thanks!
Ross


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: tstone on December 30, 2016, 12:02:45 PM
Is there a set wire length from the 90 degree bend to the scale its self? I have decided its time to make a torque meter, but I would like to use a standard scale as I fly everything from mini sticks to planes using 3/32 rubber and would like to not have to make 3 different torque meters. I am going to an event late January to fly primarily A-6, I made a flight earlier that broke the junior cat 1 national record without a torque meter and want one to get more consistent times as I am going to the same place to try and make some official flights.


thanks!
Ross

Ray Harlans' torqur meter will suit you fine, here is the link.
http://www.indoorspecialties.com/index1.html


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Rossclements on December 30, 2016, 01:29:46 PM
Is it the one for Write stuff? I have looked at that but the tourque range seems a little high, it seems like it is for 1/8th and 3/32, the a-6 uses something like .34 thousandths.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on December 30, 2016, 01:38:45 PM
You can buy a FliteTork digital meter from Mike Kirda at propblocks.com (email at [email protected]). Many are being used around the country for all classes of indoor models.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Rossclements on December 30, 2016, 04:40:13 PM
I have looked at those but it is a out of my budget, right now all of my money is going toward a rubber stripper.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Hepcat on December 31, 2016, 12:37:41 PM
Ross,
-As I say in the first paragraph you don't have to read all I have written below but one attached graph will tell you what wire size is needed for what torque and the table will tell you how long the wire must be.  A picture of one of my own torque meters is attached to reply #15 on this thread and costs virtually nothing.  The electronic torque meters are not necessarily better. The twisted wire type with a large dial are often easier to read when winding.
I have drawn up a couple of graphs (attached below) that I hope will be of help to people interested in making torque meters.  First, for those enquiring minds that need to know, I will give some background with a nod towards mathematics – you don’t have to nod back, the graphs work without any mathematical fiddling so if you want you can jump straight to the paragraph headed HOW TO SELECT A TORQUE WIRE.

The torsion formula for round bars looks like this:

T/J = 2f/d = GA/L

It is in three parts separated by equal signs and any two parts can be used together.  T is torque in inch.lb, J is called the polar moment of inertia but is simply calculated from the wire diameter so J=pi.d^4/32, f is the stress in lb/sq.in, d is the wire diameter in inches, G is known as the Modulus of Rigidity, a characteristic of the material, measured in lb/sq.in, A is the amount the bar is twisted in radians, L is the length of the wire in inches.

Dealing first with the material characteristics, I think a maximum stress of 50 tons, 112,000 lb/sq.in is sensible for wires of this type and size and that is what I have used for the graphs. (Note, some torque wire calculators on the Internet do not even consider stress which makes them useless.)  I have used a figure of 11,500,000 lb/sq.in for G, the Modulus of Rigidity, again well established for this type of wire.

I recommend that you use one full turn as the maximum deflexion, this gives the best scale for accurate reading.  This may not be so important for outdoor work where the main consideration is the maximum torque in the motor but for Indoor flying where maximum turns are not always used, where overwinding and backing off to a torque is usual and where it is often useful in testing to know the landing torque then accurate torque figures are good.  Accuracy is good for rubber testing as well.  The graphs are based on one full turn and there is no worry about overstressing the wire because the stress is calculated at one full turn.  (Although not of major importance the fact that one full turn in radians is equal to 2 pi is a convenience!)  Nearly forgot!  The graphs assume one full turn.

To produce the table I took the  2f/d = GA/L  part of the equation, used the figures mentioned above for f and G, did some rearranging and came up with the following interesting equation:
L = 323d  i.e. the working length of the wire should be 323 times the wire diameter in all cases for one full turn.
To produce the graphs (they are both the same, just a different range of sizes) I used the T/J = 2f/d part of the equation and slipped in a 16 to change the in.lb of torque into in.oz.  Rearranging gave the following:
T = 352,000d^3  i.e. the torque at one full turn is 352,000 times the wire diameter cubed. 

HOW TO SELECT A TORQUE WIRE
All you have to do is decide the maximum torque you want to measure, find it on the left hand scale of one of the graphs, run across to the graph line and then down to the wire diameter.  Look on the table and find the necessary active wire length for that diameter.

Addendum
If you really do want to save a little length on the torque meter at the expense of the simplicity of a full scale reading being at max safe torque then you can do it with the graphs, probably as quick as on a special calculator and certainly with more clarity as to what is happening.  An example should make things clear.  Assume you want the meter to handle 3 in.oz  maximum torque.  The graph will suggest 0.021 diameter wire, and the length table will give a wire length of 6.78 inches.  To use a shorter wire choose a larger diameter, say 0.024 diameter, this will take a torque of 4.85 at Full Scale Deflexion at a wire length of 7.75 inches.  Now you only want this new wire to take 3in.oz of torque which is only 62% of the 4.85 in.oz which would occur at the full 360 degree twist.  So the 3 in.oz figure will appear at 62% of 360 which is 223 degrees on the dial and the thick wire will only need to be 62% of the 7.75 inches which is 4.8 inches long.

John


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Ex Member on December 31, 2016, 01:12:53 PM
Very well explained John.

Just jumping in here to add to your explaination with a couple of pieces of advice.  1) The torque equation has extreme sensitivity to wire diameter, due to the diameter to the power of 4th term to derive the polar moment of area.  So you must measure the actual wire diameter as accurately as you can - huge errors in measurment can occur otherwise.  Use a micrometer if you can hold of one.  2) The modulus of rigidity is sometimes called the "shear modulus" which may be helpful when googling for values...  3) All of John's equations will also work with SI units too if you are anywhere other than the states (and maybe are a bit younger  ;) ;D)

Andrew



Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: mkirda on December 31, 2016, 01:19:53 PM

Just jumping in here to add to your explaination with a couple of pieces of advice.  1) The torque equation has extreme sensitivity to wire diameter, due to the diameter to the power of 4th term to derive the polar moment of area.  So you must measure the actual wire diameter as accurately as you can - huge errors in measurment can occur otherwise.  Use a micrometer if you can hold of one.

 Very good advice here as some word sold is actually undersized. I.e. 0.008" may be only 0.0075"

Regards.
Mike Kirda


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on December 31, 2016, 01:41:20 PM
Two points:

1. However you make a meter it is always advisable to calibrate it and use a dial face based on your calibration.

2. Using the largest dial face you can stand and using a wire length that will allow winding more than one full turn can give you a meter that can be used for multiple classes. Even using this plan I had 2 meters before I went to a digital meter. LPP and F1M launch torques can be over 1 in-oz. A6 can be from .1 to .4. EZB can be less than .1.

And a final word - when flying A6 at Kent or any other site where ceiling contact is a real bad idea I've often had to measure my launch torque to 3 decimal places to get to the ceiling and not get hung.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Hepcat on December 31, 2016, 02:38:08 PM
Mike Andrew and Bill,
Thank you very much for the additional comments. It was very remiss of me not to mention them.  I think a lot of us are engineers and are so familiar with tolerances and other oddities of life it does not always occur to us to dot the i's and cross the t's, particularly as a reply gets longer and longer. Thanks again.
John


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Art356A on December 31, 2016, 03:22:05 PM
The digital torquemeter was invented as a zero cost device (using a $10 scale that all indoor builders already had) for calibrating the homebuilt disc/wire meters. Then it was found that the calibration device, though crudely made, could be used by itself as a meter. The concept was picked up by some real engineers and machinists, whose brains and fabrication skills far exceeded those of the inventor, and now we have the meters that are available for sale.

The original meter, slightly upgraded, is still in use by the inventor. It's pictured on page 2 of this thread, reply 27.

As an aside, have the music wire alloys never changed? Does today's .020 wire have the exact same twist resistance as the .020 wire from 50 years ago when some of these calculations were made? A lot of builders feel that the bending resistance isn't the same.

a.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Rossclements on December 31, 2016, 03:54:49 PM
Hi all,
Thanks for all of the useful advice! Aardvark_bill kindly has sent me a torque meter that can go up to 1 oz. inch, this should work well for a-6. I think I will make some other wire meters and then make an electronic meter an see which one I like best.
Hepcat, Thanks for the table. I have never seen the table, thanks!
What torque ranges would mini stick, f1l, f1d, and penny plane use?

Thanks for all of the help!

Ross


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: mkirda on December 31, 2016, 04:08:59 PM
Hi all,
Thanks for all of the useful advice! Aardvark_bill kindly has sent me a torque meter that can go up to 1 oz. inch, this should work well for a-6. I think I will make some other wire meters and then make an electronic meter an see which one I like best.
Hepcat, Thanks for the table. I have never seen the table, thanks!
What torque ranges would mini stick, f1l, f1d, and penny plane use?

Thanks for all of the help!

Ross


F1D and F1L use similar rubber sizes and torque ranges to a max of around .5 in-oz on F1D.
Depends a lot on the loop length. F1L might be slightly less, .4 or so.

LPP can be over 1 in-oz. I've gone that high before.

Mini stick uses very thin rubber, so the max torque might be .1-.2.

Check out one of Fred Rash's rubber spreadsheets.

Regards.
Mike Kirda



Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: leop on December 31, 2016, 05:01:58 PM
As John mentioned above, currently G for music wire (ASTM A228 specifications) is given as 11.5 Mpsi.  But this value is for the wire just after the final cold draw for size.  If the wire is cold worked any more, even by coiling it, the value for G decreases.  The dislocations caused by the cold working (other than by pure tension drawing), allow the grains to slide more easily past each other.  This lowers the shear modulus, G.  For the music wire I use, after breaking in the torque meter (by twisting back and forth to +-80% full torque - about 100 times), the value of G I measure is 10.3-10.5 Mpsi.  In further use, after about a year or so, my wire torque meters need to be redialed as the G decreases to about 10 Mpsi.  In my experience, this value stay constant (at least until the wire breaks).  This lessening of G occurs in all the music wire I use: Precision Brand, K&S, and guitar strings.

I initially dial my wire based torque meters using a G of 10.3 Mpsi.  After six months to a year, I need to recalibrate, print out a new dial face, and redial for a finally time.  I also calculate my own initial wire lengths (5.15" of 0.0.015" wire for a 1.0 oz-in meter and 5.20" of 0.016" wire for a 1.4 oz-in meter using a G of 10.3 Mpsi). 

I suggest erring on the short side for the wire length.  If redialing is hard, the torque twist coefficient can be lowered for a built wire torque meter by slightly sanding a portion of the wire to reduce the diameter (I have used a small piece of wet/dry carborundum paper stuck on a toothpick to get into the tube of the meter).  Be careful as just one swipe or two will make a noticeable change in the twist coefficient.

Jeff Hood once had a utilities website that would calculate wire lengths and produce dial face image files.  Unfortunately, that site no longer exists.  Jeff started a new website but as yet, only the wire length calculator works.  However, Jeff's calculator uses a G of 12 Mpsi.  One can still use Jeff's output by multiplying the output length by 10.3/12 (or whatever G one wants to use instead of 10.3).  Jeff's current wire length calculator is at:

http://indoor-utils.jhood.com.s3-website-us-east-1.amazonaws.com/#/tmeter

LP


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Ex Member on December 31, 2016, 06:03:44 PM
As far as I know the value of G doesn't change with cold work, I was always taught that it rather more depends on the alloy and doesn't really change to the extent you are saying.  You can alter sorts of things by working a material, hardness, tensile strength, ductility etc but the significant manipulation of the shear or Young's modulus is not possible.  The Young's modulus (stiffness) always stays in a pretty tight range for a particular alloy, for instance all aluminium alloys pretty much stay in the range of 68-70 Gpa, and steels 200-210 Gpa...  brass alloys tend to wander more due to a much larger range of the percentage of the alloying materials (copper and zinc) that re used for various grades...

However I repeat this is what I was taught, other opinions and facts welcome  ;D ;D

Andrew


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on December 31, 2016, 07:30:08 PM
I can make a dial face for anyone that needs one. All I need are the diameter of the face and the torque at 360 degrees rotation.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on December 31, 2016, 11:11:13 PM
Here are some samples from a pdf converted to jpeg.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on December 31, 2016, 11:18:10 PM
I don't recommend making a dial face based on a calculated value for the torque at 360 degrees. I would strongly suggest measuring to get that value. That removes all the guesswork about wire torsional strength and also for any inaccuracies in building the meter.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: dslusarc on January 01, 2017, 10:53:11 PM
Here is a 3D printed digital one I am making from the files created and posted on Facebook by Dmytro Silin. I have been using torsion wire meters for ~30 years now. The first ones were ones I made, but these four which I typically use were made by Tim Goldstein some years ago. Each one has a different wire size for a different torque range. I have never calibrated these and see no real reason to have them precisely calibrated as all that matters to me is the relative torque from flight to flight using the same meter. The torque values printed on the dial are calculated on the measured wire diameter and length of the wire. Its close enough for me. But like Bill said, a printed dial based on a measured/calibrated number would be more accurate.

Don


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on January 19, 2017, 06:55:54 PM
Here are some samples from a pdf converted to jpeg.

I guess I should point out that there's no charge for making a dial face. Probably won't matter since no one has ever asked for one.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Landed on January 21, 2018, 07:21:04 AM
Her is my winder/torque meter in one.
Sorry this is for out door


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Dan Snow on October 11, 2018, 08:51:53 AM
Being brand new in this hobby, and on a fixed income, I need to be creative sometimes when it comes to gathering up all the non-flying stuff required to get these models in the air. I built Paul Bradley's winding stooge and re-purposed a couple of shop tools rather than buying new ones.

But I needed a winder. I don't plan to fly big high power endurance models so I didn't need something like the $99.50 Sidewinder or, heaven forbid, the $400 F1G!!  Talk about sticker shock!! But at the same time I wasn't thrilled with spending $20-$30 for a plastic winder with nylon gears. So I started looking at winders made from hand drills.  I had one from my Dad, but unfortunately I believe it was looks when some low-life's stole a tool bag out of my truck.  Went on Amazon and started looking and eventually settled on one from China for $25. Cast frame, double pinion gears decent fit and finish.
I could have spent less but I do want it to last, and of course I could have spent a lot more, but it's gonna be a uni-task tool so I didn't need to waste money on it.

When it arrived, I checked it out, seemed to work okay. It has a slight hitch in its giddy-up at one spot on the main gear, possibly a slight deformation of the teeth in that area but not enough to be an issue. I then drilled a hole in the shaft, bent the hook out of .090" steel wire, inserted it through the hole, then applied about a dozen wraps of .030" copper wire which I then soldered to the shaft to lock the hook in place.

Tah-Dah! I now have a winder! The ratio is 4.25:1 which while not spectacular is decent. I was planning to mount a counter to it, but when I got out the counter it clicked twice and broke. Rats.
At some point I will get another and mount it but for now I think I can remember that 100 cranks will give me 425 winds.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: calgoddard on October 11, 2018, 12:23:09 PM
Dan -

I am impressed by your diligence and ingenuity.

I have a couple of comments about your winder that might prove helpful.

It is hard to tell the size of your winder, but it looks big enough to wind a 16 x 1/8-inch rubber motor like one would use in a Gollywock.  When you wind, you will need to step out and stretch the rubber motor.  So you need a D-shaped handle to securely hold the winder as the pulling force will be substantial.  See the attached picture of my Merrill winder which has this type of handle.

Also, the .090-inch hook is a little too robust.  I don't think it will fit through the hole in a medium size Crockett hook. You will need to use a Crockett hook or a similar hook on the front end of a multi-strand rubber motor in order to be able to remove the rubber motor from the winder and connect it to the prop shaft hook. I would go with a .062-inch music wire hook on your winder.  

Build a torque meter using the plan from Herb Kothe.  It will cost less than $5 in parts.  Wind to torque.

Use a blast tube.  This has been covered elsewhere, probably in my thread about building the Korda C Tractor under the Old Time Rubber topic.

BTW, I bought my used Merrill winder for $35 a few years ago.  I think it has about the same ratio as your winder. It came with a mechanical counter already installed. The counter is the little black box. I later added the cylindrical torque meter mounted on the end of my Merrill winder.  It was purchased for about $100 from Volare products. The Kothe torque meter is a separate tool that will work fine, but its use involves added steps in the winding process.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Pit on October 11, 2018, 01:43:41 PM
Torque meters are the cat's meow with rubber winding.  I've been wanting to build a Kothe style meter for my smaller models, but I can only get wire in metric sizes.  All the info I've found relates to imperial.

Cal...
I plan on ordering one of George's meters for Christmas if the shipping and/or the Customs fees don't go thru the roof.  Have you given yours a wring-out and how do you like it?

Pete


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: calgoddard on October 11, 2018, 02:25:33 PM
Pit -

I think the plan for the Kothe torque meter has a formula for figuring out the length of the music wire segment to use. Therefore precision in the diameter of the wire is not critical.  For indoor models, I believe a 6-inch segment of .020" music wire would work nicely.  There are many ways to calibrate a homemade torque meter.

The Volare torque meter is an example of excellent engineering and fine craftsmanship.  It is very reasonably priced.  I have used my Morrill winder equipped with a Volare torque meter regularly over the past few years and it performs very nicely.

I would prefer that the Volare torque meter have a finer resolution.  For example, 2 on the meter is about 20 inch-ounces of torque. I rarely need to wind past 30-inch ounces of torque.  I don't fly Wakefields.  The meter goes from 0 to 10.  However, there are clearly readable line markings on the indicator drum between the digits.  My recollection is that they are in tenths.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: USch on October 11, 2018, 03:30:22 PM
Just what I found in my pc, a pdf from Ken Rice. The formula can be used to determine the deflection from any diameter and lenght of wire.

Calibrating a Torque Meter by Ken Rice
From: "Batsheet" via: Okie Free Flight Flyers
Most of the torque meter construction articles that I've seen call for calibrating the finished instrument by comparing it to a known-accurate torque meter, or by using a system of measured weights and moment arms. Neither of these is easy to do with any precision. Fortunately, there is a standard engineering formula for calculating the angular deflection of a solid shaft that works nicely for determining the dial marking instead. The simple formula is:
a = (C * T * L) / (D^4 * G)
The formula shows how many degrees that a shaft will twist, given the diameter and length of the shaft, and the amount of twisting force. The parameters for this formula are described below in both US and standard units (standard in parentheses):
a = angle of pointer deflection in degrees (degrees)
C = constant: 36.5 (584)
T = torque in inch-ounces (newton-millimeters)
L = length of the music wire torsional element in inches (millimeters)
D = diameter of the music wire torsional element in inches (millimeters)
G = torsional Modulus of Elasticity for music wire in lb/sq in (newton/sq mm)
Wire Size   G
less than .032 (.81)   12,000,000 (82 740)
.011-.062 (.84-1.6)   11,850,000 (81 700)
.063-.125 (1.6-3.2)   11,750,000 (81 010)
.126-.250 (3.2-6.4)   11,600,000 (79 980)


hope that helps, Pit

Urs


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Pit on October 11, 2018, 05:37:22 PM
Thanks guys!
Urs... now that I see that article I remember saving it (Duh!).  It didn't make the migration to the new confuser which is why I couldn't "find" it.

Pete


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Dan Snow on October 11, 2018, 10:10:05 PM
Dan -

I am impressed by your diligence and ingenuity.

I have a couple of comments about your winder that might prove helpful.

It is hard to tell the size of your winder, but it looks big enough to wind a 16 x 1/8-inch rubber motor like one would use in a Gollywock.  When you wind, you will need to step out and stretch the rubber motor.  So you need a D-shaped handle to securely hold the winder as the pulling force will be substantial.  See the attached picture of my Merrill winder which has this type of handle.

Also, the .090-inch hook is a little too robust.  I don't think it will fit through the hole in a medium size Crockett hook. You will need to use a Crockett hook or a similar hook on the front end of a multi-strand rubber motor in order to be able to remove the rubber motor from the winder and connect it to the prop shaft hook. I would go with a .062-inch music wire hook on your winder.  

Build a torque meter using the plan from Herb Kothe.  It will cost less than $5 in parts.  Wind to torque.

I took your advice and made a new hook out of .060 music wire. I have heard of the Crockett hook, might have even seen a picture of one, but clueless as to how they are used!
Remember, the Beaver is likely the largest model I will fly, so I don't expect to be trying to wind any throw you over the pickup truck strength motors.  I am planning to do something to increase my grip on the winder, just not sure what yet.  The handle is plastic and appears to be somehow welded/riveted to the frame.

I've been having a lot of fun building, guess it's time to start learning about motors, torque, and that sort of thing. I won't be competing, just flying for fun. Scale is my thing, and it's pretty much non-existent around here.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Dan Snow on October 29, 2018, 09:59:03 AM
Second step taken in converting a hand drill into a winder.  I cannot determine exactly how they attached the plastic handle to the drill frame so I'm leaving it in place and using it for now. At some point if I find the right size aluminum straps I will cut the plastic handle off and fabricate a handle similar to the one shown by calgoddard.

For now I have drilled through and inserted a 5/8" dowel, then locked the dowel in place with a #6 wood screw. This should be sufficient since I don't expect to be winding any 1/4" multi strand monster motors! :)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: USch on October 29, 2018, 02:02:30 PM
Dan, if you dont know how the handle is fixed, drill a 2mm hole through handle (metal sleeve) and drill body and insert a piece of 2mm wire. See the foto with the arrow.
These drills are build to be in compression between drill body and handle during use. Instead you/we use them in traction. So the handle could eventually slip off with a damaged model as a result.

Urs


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Dan Snow on October 29, 2018, 03:33:02 PM
You mean like this? :)  Good idea, Thank You.

A couple wraps of electrical tape will protect tender digits from the ends of the evil wire!! ::)

I figure it will show signs of loosening before it lets go, at which point I stop using it until I make the replacement handle. Currently the biggest motor I'll be winding is 4 17" strandsof 3/32"


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: USch on October 29, 2018, 03:59:07 PM
Well, could be done more pulite  ;)
Maybe with two self tapping screws with round heads ???

Urs


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: flydean1 on October 29, 2018, 09:30:51 PM
My first "real" winder was a cheap Stanley hand drill with wooden handle that threaded into the main body.  Had only one pinion as well.  Handle shaped like a broomstick.  Came apart on the first decent motor, 4 loops of 1/4 inch.  Model not damaged.  Spent the next 2 weeks lurking around flea markets and garage sales to find a drill with two pinions and a decent metal frame.  Made a proper handle but had to pin the whole thing together as the stretching force caused the main shaft to disengage from the pinions.

Went to a much bigger drill.  It was last used by my grandson to wind his P30.  He was quite small for his age so I made a strap out of an old pistol belt attached to the handle.  He would climb into the harness and lean back.  Did pretty well watching the torque meter while winding.  Had some long flights with that one.  Still have the winder but now use a proper Sidewinder.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Pit on October 29, 2018, 09:54:26 PM
The drill that I converted also has only one pinion and a screw on handle.  The pinion on mine was pinned to the shaft.  I also made up a winding gizmo in lieu of the chuck, that is also pinned to the shaft.  Has no problems with 25-30gram SENATOR motors, but I haven't had a chance to try it on a Coupe or F1b motor yet.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Dan Snow on December 29, 2018, 08:32:45 AM
While wandering around YouTube I came across an interesting video regarding winders.
this fellow had a winder that instead of a hook, had two loops of soft looking straps that hooked over the prop blades and allowed winding without disconnecting the motor from the prop shaft. I realize this wouldn't work on some of the delicate props of indoor, No-Cal and such type models, but for larger models with sturdier built and plastic props it seemed like an easier, quicker way to wind 'er up.

Has anyone here tried this technique?


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: tom arnold on December 29, 2018, 10:51:07 AM
Yes, and the best I can say about it is: awkward.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Indoorflyer on December 29, 2018, 10:56:42 AM
Having a blast tube and torque meter are more important to me than "easier and quicker."


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Dan Snow on December 29, 2018, 10:58:31 AM
Awkward is what I was thinking as well. By quicker and easier I was referring to not having to unhook the motor from the prop shaft and reattach it after winding. Trying to get the two loops off the prop without dropping the winder or damaging the model looks like it would need some practice.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: flydean1 on December 29, 2018, 04:31:51 PM
Yes, and in addition, makes it impossible to use a winding tube.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Dan Snow on December 29, 2018, 08:16:06 PM
This is the video I found that shows the floppy straps around the prop.

https://www.youtube.com/watch?v=7Anwy6p6pi8 (https://www.youtube.com/watch?v=7Anwy6p6pi8)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Dan Snow on January 05, 2019, 07:17:17 PM
Can someone here show me where I went astray?

I built a torque meter per instructions found in a video by one Doyle Blevins. I used .015" wire and bent it up, sandxiched it between two cards, covered the ends with heat shrink tubing and bent the hooks into the ends. all per instructions. Then to test it I hooked it up to a 4" 3/32 wide rubber band and after putting maybe 150 turns I discovered that I had twisted the pointer almost 300 degrees!!

That ain't gonna be of much use when I go to wind a real motor, so I must have screwed up somewhere.
Here's a link to Mr Blevins video. https://www.youtube.com/watch?v=kDoMzyeIzWA (https://www.youtube.com/watch?v=kDoMzyeIzWA)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: mescal1 on January 05, 2019, 08:21:06 PM
I'm pretty sure that your wire size is too small for a short 3/32" motor.  That torque meter would really only be used on an indoor model.  If you are planning on flying something a littler heavier (such as the plan on his video) you should probably move up to 0.063 (1/16") wire size and try again.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: mescal1 on January 05, 2019, 08:28:49 PM
Here's a link to a torque meter by the great Herb Kothe!   http://www.flyingacesclub.com/PFFT/TorqueMeterKothe.pdf 


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: flydean1 on January 05, 2019, 09:39:32 PM
Looked at the video.  I have no idea where he is coming from.  Never heard of him but I am hardly an indoor expert.  Maybe someone else knows him.  He must fly only very light indoor models.  His meter might handle .060 Tan SS max.

Build the Kothe meter.  Use the math formula to determine the wire size.  The illustrated 50 oz-in shown will handle anything up to a Gollywork.  You might want to aim for around 20 if flying smaller Rubber Scale models.  The meter I use for P30 is 11 oz-in.

For the tube, I used an aluminum arrow shaft.  Archery supply stores have them and they are not too expensive.  I got mine from the trash bin behind a sporting supply store for free.  A large Peck Polymers thrust button was a perfect fin in each end.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Dan Snow on January 05, 2019, 09:54:25 PM
That's what happens when you don't know the right questions to ask! :)  I heard nothing on the video about it being for indoor.  So now I have a meter if I ever am delusional enough to try and build an ultra fragile indoor flying thingy! :) :) :)

Will look into building a Kothe meter.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: ram on January 05, 2019, 10:51:18 PM
Doyle has attended the indoor NATS several times, AND, this is the INDOOR FF Forum after all so not surprised at the size of the meter.

Rey


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Bredehoft on January 05, 2019, 10:59:27 PM
Yeah, using Kothe's formula, it looks like that video would produce a torque meter good for about 1 in-oz for 360 degrees.  While that is not how I made my torque meters, it looks like it is good, in principle and should work just fine - for small indoor models.

--george


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Dan Snow on January 06, 2019, 07:58:15 AM
Not being good at higher math anymore, I have tried running Kothes simplified formula through my calculator and I am noot getting the right results. When I try his formula of
Angle=(.00000332)(80)(15.9)/(.063)(.063)(.063)(.063)  instead of getting 267 I get 1.064

What am I doing wrong?


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Bredehoft on January 06, 2019, 08:36:54 AM
You forgot your order of operations (MDAS - My Dear Aunt Sally - Multiply Divide Add Subtract)

You need to group the numbers properly:

Multiply these (.00000332)(80)(15.9)  and set that number aside .00422304

then

Multiply these (.063)(.063)(.063)(.063)  and set that number aside  .000015752961

Then divide the first by the second

.00422304/.000015752961 = 268.079...

If you notice, in his formula on the page, he has brackets where you did not - those are very important.  WITH them, you can just punch the brackets, numbers, and symbols into your calculator.   Without them, you get the wrong answer.

On additional comment (and maybe you were just testing your math) - that formula with those numbers will give you a 80 in-oz torque meter.  That is a very heavy piece of equipment, suitable for BIG rubber ships.  If you are going to fly things say P-30 and smaller, use the numbers at the bottom for 20 in-oz - or maybe 40 if you want some Old Time Rubber ships.

--george


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Dan Snow on January 08, 2019, 07:24:40 PM
If/when I get around to making another torque meter it will be the 20 oz/in one. I was just running through his calculation to see if I got the same result. Well, I got the same result, Twice! But it was the wrong result! Thanks for putting it in simple terms even I could understand! :)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Dan Snow on February 10, 2019, 06:04:35 AM
Okay all you Experts out there, I need some guidance here.  I have started gathering all the bits needed to make a 20 in/oz version of Kothe's torque meter, and would like to know how critical is the diameter of the aluminum tube? The aluminum arrow shaft I found has an OD of .344" rather than .312"

Anyway, the part that has me a bit flummoxed is the connection of the wire/alum. tube/brass cap. If I'm reading the construction notes correctly, after forming the hook at the winders end, I solder a pointer, slide on the alum. tube and then solder the cap onto the wire at the specified distance for the meter I'm making.

Hold on a minute here. As I look at the instructions, they tell me that to make a meter for 20 in/oz I need a length of 19.8 INCHES between pointer and cap of .047" wire. Then I need to ADD 12-14" of wire past that if I want to use a blast tube on my models! Add in 2-4 more inches from the pointer to the winder end hook and I'm looking at 3 Freakin' Feet!  That can't be right, can it? I can see this thing getting bent all to heck just moving it around, going to and from the field, plus very awkward to use solo. 

So is there any reason why I can't make the distance shorter? If I'm doing the math correctly, ( a very BIG if ), if I use a distance of .047" wire a deflection of 109 degrees is 20 in/oz, correct?

Okay, sorry about the digression there, back to the original question: If the distance between cap and pointer is critical, what is the best sequence to follow to get it assembled so you dont either melt the epoxy or char the dial face when soldering things together?  I suppose I could cut a slot into the dial face to slide it over the wire, while sliding the support for the dial face onto the aluminum tube before inserting the wire, which gets bent up After inserting it into the tube.................

Deep Breath!!! Okay, I'll stop now.   All silliness aside, how critical is it to keep epoxy out of the tube at the cap end?  and as an extra thought, if I was to make a removable extension to hook between the meterand the rubber, would that throw the calculations out the window?


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Bredehoft on February 10, 2019, 09:50:10 AM
ok, trying to answer in no particular order.

the critical dimensions for the torque meter are between where the indicator is attached (soldered) and where the tube is anchored to the wire.  These are the two reference points - the indicator is obviously attached to the wire and the dial is attached to the tube - which is attached to the wire.  The meter measures the angular twist of the wire between those two reference points.  So, it is critical that you are able to securely attach BOTH points and relatively accurately.  Note that what is important in measuring torque is your RELATIVE torque to past and future measurements.  You can do fine with a meter that is not EXACT to external references (such as an accurate in-oz scale) as long as YOU know where you are on YOUR meter.  The only issue that comes about if your meter is off calibration is that when someone says "I wind to 5 in-oz", 5 on their meter may not be exactly where 5 is on your meter.

Any length of wire beyond the two reference points will not affect the needle indicator.  Some people do make the external wire long enough to use with a blast tube.  This simply cuts down on pieces of equipment they use during winding as it combines the blast tube wire and the torque meter into one.  This is not necessary, if you are prepared to use two pieces of equipment.

The diameter of the tube DOES NOT MATTER, as long as the wire does not bind inside the tube.

My calculations for 0.047 wire and 109 degrees of rotation at 20 in-oz is a length of wire 8.01" long.  I made a spreadsheet based on Kothe's formula and it has wire diameter across the top and torque down the side and I input the desired deflection.  Your 19.8" of 0.047" wire at 20 in-oz produces a deflection of 270 degrees.

-george







Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: MKelly on February 10, 2019, 12:57:23 PM
Dan,

A few thoughts from an inexperienced torque meter user - I've made a grand total of one torque meter and have used it for the last two years, so take this for what it's worth.  George has covered the mechanics of the meter very well, not much I can add to that.

20 oz-in is a lot of torque.  I made mine to read to 12 oz-in and have only used it over 6 oz-in when winding motors to destruction on a test bench.  For small models like your Hemiptere, Chipmunk etc you'll probably never wind to over 4 oz-in.  I found that for my models under 20" span I'm usually winding to 2-3 oz-in, and my 12 oz-in torque meter is too high-range for that.  Winding it the low-end of the meter makes it difficult (for me at least) to have confidence that I'm winding to a repeatable performance point from flight to flight.  I'm going to build another meter scaled for 6 oz-in max torque to use for these smaller models.

Take a look at the models you plan to use the meter on and measure the length between hook and peg.  My models are all under 27" span, with hook-peg lengths between 6-10 inches.  I've standardized on roughly 11"x3/4" diameter blast tube for my larger models and 8"x5/8" diameter for my smaller models.  With that knowledge you can decide whether to extend the torque meter wire (outside the critical length George described) towards the model long enough to allow you to pull the blast tube up over the torque meter or to make an extension wire with hooks on either end that will let you pull out the blast tube.  I've been using an extension wire as follows:

1. Hook the extension wire to the motor
2. Slide the blast tube over the extension wire and rubber into the model and hook it to the rear peg
3. Remove the extension wire
4. Hook the motor to the torque meter
5. Wind
6. Disconnect the torque meter and hook on the extension wire
7. Unhook the blast tube and slide it out over the extension wire
8. Disconnect the extension wire from the rubber
9. Hook the rubber onto the noseblock and insert the noseblock in model
10. Go fly!

As you can see, you can eliminate some steps if you've built the extension into your torque meter - that's what I plan to do on my next meter.

I had some problems with the wire breaking loose from the fitting holding it to the tube at the model end of the meter.  This is probably mostly due to my poor soldering skills.  To remedy this I filed a notch in the fitting, bent the wire to slide into the notch, then formed the hook from there (see picture).  This made the solder joint much stronger, hasn't broken since.

One other thought:  on my first meter I used a ring of 1/2" ply as the dial face.  This was a mistake, as the mass of all that ply causes the meter to whip around while winding.  The rubber dances around with the meter, shaking the model in the stooge.  The meter also oscillates a lot during winding so you have to stop cranking and let it settle down to get even a rough idea of what torque you're at.  For the next meter I'm going to use some thin light plywood for the face - something just strong enough to avoid damage in the flight box.

Anyway, there's lots of folks here that know a lot more than I do, but I hope this helps you a bit.

Mike



Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Dan Snow on February 10, 2019, 02:09:56 PM
Thanks for the info  George and Mike.

I picked 20 in/oz as a starting point because I will be building primarily in the 16+ wingspan. Below that things get a mite too tiny and delicate for these old fumble fingers.

I measured the planes I have and the average peg to hook is in the 7-8" range. My Otter, 22" and the upcoming Chieftain 26" will be longer at 8.5' and 9.5" respectively. two

I have enough bits to make 2 meters so might make 2 different ones.

George, any chance of getting a copy of your chart?  I have some .047 and some .031 wire.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Dan Snow on February 11, 2019, 07:13:33 AM
I went back and went over the instructions again and I think I have things figured out.

So I'm planning to build one with  6 " of .031" wire that will give 12 in/oz at 258.8 degrees.  If I do the calculations correctly that should give the following:
4 in/oz = 86.3 deg
6 in/oz = 129.4 deg
8 in/oz = 172.6 deg
10 in/oz = 215.7 deg


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Dan Snow on March 07, 2019, 01:31:45 PM
I haven't started making the torque meter yet for many reasons, life stuff, interruptions etc etc.  And I still have questions. For the mathematically impaired is there a source one could go to to look up say, recommended torque for given motor?

Ideally is there somewhere I can see a chart that recommends torque "X" for "Y" strands of "Z" rubber?


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: RalphS on March 07, 2019, 02:07:26 PM
Dan,  I recommend the late John Barker's (Hepcat on this site) PROP PICKER Excel spreadsheet.  I don't know if John left a copy on here but I could send it through to you if you PM me.  I know that John used to refine his lovely mathmatical solutions from time to time and I know that my copy is a very early version.  Jon (Yak52 on this site) may have a later version so it may be worth asking him.

John also produced some simple solutions for torque meter wire selection, wire length for home produced torque meters.

Ralph


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: frash on March 07, 2019, 02:16:33 PM

Turns, Torque Calculator for Super Sport Rubber (Revised 2014-10-05) (frash)
Tips, Tools and other Helpful Stuff

Date added: 10.05.2014 19:00


Home / Miscellaneous / Tips, Tools and other Helpful Stuff

If you are willing to work in grams for weight and inches for length, this one in the plans section may work for you.

Fred Rash


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: applehoney on March 07, 2019, 03:36:31 PM
Dan,   I see little purpose in such a chart trying to provide firm torque values for various strands of rubber, the properties of which can vary from batch to batch - even from ends of same batch -  and whether the motor is new or used ... and how much used.    Furthermore, meters do not necessarily agree with each other so the only reading that matters is that shewn by your unit.  One meter can serve for most all outdoor models ...  a more delicate version for indoor use.

In my experience the sole practical purpose of the essential torque meter is for consistency in the flying ability of a model.   When such is fully trimmed to maximum performance upon its chosen strands and weight and the torque duly noted then the model may be flown with any similar motors wound to that value, regardless of any energy variances between such, with confidence that its power pattern will be consistent.  Motors should be made to weight, not length.

After acquiring a meter, many years ago, I soon dispensed with a counter after I noticed how the number of turns varied between several apparently similar motors wound to same torque; or the same wound for a second time.

Keep notes of the full-trim torque reading for every model you fly so that you can reference same when one is aired after a lengthy period of disuse, confident it will fly as before.  Assuming no warps crept in meantime, of course  :)


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Olbill on March 07, 2019, 04:53:10 PM
Dan,   I see little purpose in such a chart trying to provide firm torque values for various strands of rubber, the properties of which can vary from batch to batch - even from ends of same batch -  and whether the motor is new or used ... and how much used.    Furthermore, meters do not necessarily agree with each other so the only reading that matters is that shewn by your unit.  One meter can serve for most all outdoor models ...  a more delicate version for indoor use.

In my experience the sole practical purpose of the essential torque meter is for consistency in the flying ability of a model.   When such is fully trimmed to maximum performance upon its chosen strands and weight and the torque duly noted then the model may be flown with any similar motors wound to that value, regardless of any energy variances between such, with confidence that its power pattern will be consistent.  Motors should be made to weight, not length.

After acquiring a meter, many years ago, I soon dispensed with a counter after I noticed how the number of turns varied between several apparently similar motors wound to same torque; or the same wound for a second time.

Keep notes of the full-trim torque reading for every model you fly so that you can reference same when one is aired after a lengthy period of disuse, confident it will fly as before.  Assuming no warps crept in meantime, of course  :)

I wish these last few messages could be moved to a more appropriate topic. This topic is for indoor flying and I would disagree with nearly all of the points in the above reply if they were applied to indoor flying. A beginning indoor flyer trying to learn about choosing and winding motors would be totally misled if he tried to apply these points to competitive indoor flying.


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: applehoney on March 07, 2019, 07:29:49 PM
Bill, I now see that when you commenced this thread it was posted to 'Indoor Discussions', as shown in small print at the top of the page for any who choose to seek such subject. However, there's nothing in the heading description to indicate that it's dedicated to that sole purpose  and, in the subsequent nine years (all but a month) it's obvious that content has segued into more general discussion on meters, etc. from its early pages and, as is evident, the title attracts flyers from all rubber flying pursuits

I understand that Indoor and Outdoor F/F require very different skills and techniques. I note that you disagree with most of my post in what appeared to be a general subject but would be interested to hear in what way that might be so.   After all, rubber is rubber and whether utilised for either flying purpose it has the same basic variances; however, I readily concede that  the relatively thin strandage and minimal lengths required of Indoor motors probably reduces such effect to a minimum compared to the amount of material required by outdoor motors.

I do contend that meters are not identical and that the only inch/ounce readings one should rely upon are those from one's own scale; also that a meter is the only guide to gaining similar initial energy availability from varied motors for consistent climb performance patterns once a model has been trimmed for maximum performance,

I feel these aspects apply equally to both Indoor and Outdoor flying but would be very happy, without ranquor, to learn if this is not so in some ways. I admit that I do not fly Indoor in any form but my  thoughts are directed by personal observations regarding same as Team Manager at three World Championships

Regards  - Jim




 .


Title: Re: Winders, winding stooge, torque meters, winding methods
Post by: Dan Snow on March 07, 2019, 09:24:15 PM
Sorry guys, didn't mean to start an inter-discipline kerfuffle here. In defense when a while back I did a search for winders and torque meters this thread came up and I didn't catch that it was indoor related.

Look at it from my point of view.  While I have many years experience flying radio controlled models, 99.9% of my rubber powered model experience began last August. The language and terminology regarding rubber motors is completely foreign and unintelligible to me. I have an idea of the power and usefulness of say a .35 engine versus a .60 engine, that sort of thing.  But looking at a model and determining it needs so much rubber, of such and such a size wound to such and such a torque? Not a clue.

I've tried to suss things out from Don Ross's book, and wandered through different threads here, but so far the light bulb hasn't gone on.  That's why I asked the question. I'm just a retired guy trying to learn a new hobby in a location that has very few participants so I don't have someone I can get together with over coffee and talk about rubber models and learn.