Hip Pocket Builders' Forum

Indoor Free Flight Forum => EZB, 35cm, Ministick, AROG, Livingroom Flyers => Topic started by: Alan Cohen on March 30, 2010, 06:59:27 AM



Title: Minislick -Build-
Post by: Alan Cohen on March 30, 2010, 06:59:27 AM
It's time for a new ministick. I need a fresh one for Kent. Seems I say that every year. I think I have 4 stuck up in the lights there by now. So I'm clearing the building board, pulling out that old plan and rummaging through the balsa supply. I thought I'd post the build, highlighting a few of the main processes and techniques. I think there is a better copy of the plan in the Plan Gallery.


Title: Re: Minislick -Build-
Post by: lemuel on March 30, 2010, 07:27:05 AM
Cool, I hope to learn much from you on this build Alan. I have made a micro version of this model that I fly in my house. What sort of times have you had with previous versions of this model?

regards
Matthew


Title: Re: Minislick -Build-
Post by: Alan Cohen on March 30, 2010, 08:42:34 AM
I have a micro version as well. Mine is a 5" span. Flies just as well as its "big" brother.

The Minislick has done 15:30 at Lakehurst under a 200' ceiling where it was designed for. Most of my practice with this model was trying to get it to the ceiling there. Skinny rubber, lower pitch prop etc. Consequently, I have struggled under lower ceilings. I think I approached 12 minutes under a 50' ceiling at Kent. I need a lot more practice to match prop and rubber for lower ceilings. I am trying something different with this one to try and help: Previous versions have been very stable flyers with very quick recoveries when banging into the ceiling or fixtures. That is not a desirable trait for a ministick under a low ceiling. Ideally, you would like to model to climb not too aggressively to the ceiling, bounce once and do a tail slide all the way to the floor and then climb back up again. Of course I'm exaggerating, but you get the idea. A 20' drop effectively raises a 50' ceiling to 70'. A longer cruise and less climb is also necessary for low ceilings. All I need is a clone to go out and practice while I'm handling the rest of life.


Title: Re: Minislick -Build-
Post by: Alan Cohen on March 30, 2010, 08:50:24 AM
I always start with the motorstick for indoor models. I can't seem to find old my 3/32" prop blank wood, so I went to the pile for a fresh piece. I picked a very stiff piece of 6.5# wood and checked it for grain consistency. I cut off 6" and reweighed it. This blank is a little light at 6.2# density, but I'll go with it since it is very stiff. I do not like a ministick motorstick to bend at all under full load. It's hard enough getting a repeatable launch.

I first cut the .148" motorstick using the full LE of the 5% simplex template. For the tailboom (pic #4), the LE of the template is actually the rearmost part of the model and where the stab mounts. After cutting it is turned upside down. How much of the LE of the simplex airfoil is utilized will determine the amount of negative incidence on the stab. I normally slide the template over to the left 1-3/4". For this one I'm sliding over 2-1/4" for less negative incidence. I'm hoping for less decalage and less stability.

In the last pic you can see the general layout.


Title: Re: Minislick -Build-
Post by: Alan Cohen on March 30, 2010, 09:09:19 AM
This motorstick blank is a little thick at .108". I like it more around .094". I need to plane off a bit. I used to sand my indoor motorsticks to weight and dimension until I was scolded passionately. Now, only a razor plane touches them. OK, I do a tiny bit of cosmetic sanding, but don't tell.

The tailboom also needs to be tapered. Three stepped passes with the razor plane on both sides gets the job done. Weight before hooks is 160mg. Funny, I used to have these target weights burned into my brain. I seemed to have misplaced them ??? Looking back at my plan I see my fuselage all up weight was 185mg so I think I'm OK.

Now to cut a groove at the rear of the motorstick to accept the rear hook. Then a poke with some .010mw and then inserting the hook. I little Duco and plenty of time to completely dry before handling.

Off to make a pigtail bearing. Haven't done one of these is a while. This should be interesting!


Title: Re: Minislick -Build-
Post by: Art356A on March 30, 2010, 09:16:37 AM
Are you using two different weights for the front and back of the stick and scarfing them together? Or is that an optical illusion?

My last one came out only 40% heavier than yours, big improvement from the one before that. The highest ceiling in SoFla is 26' so our problems are different.

Art.


Title: Re: Minislick -Build-
Post by: Alan Cohen on March 30, 2010, 10:05:47 AM
Actually, I just had an epiphany, Art. I had been using the same 6.5+# wood for the motorstick and tailboom previously. I just made a management decision to go lighter on the boom. I think that might be where I'm getting my stability issues. With a heavy boom I would need more decalage to keep the nose up, yes? I think my previous versions were in the neighbor of 5-6* decalage. I'm trying for 3* on this one and lets see what happens. Gotta keep the tail light. I found a really primo piece of 4.5# wood and made a new boom and motorstick. I went taller on the MS to compensate for the lighter density. The old boom weighed 50mg, the new one is 40. The MS is the same. And it's still stiffer than I will need. Here's a pic of the first and second ones.


Title: Re: Minislick -Build-
Post by: Tmat on March 30, 2010, 12:17:58 PM
Nice stuff so far Alan.

Out of curiosity (and ignorance on my part), but what about reducing the stab area to reduce some of the Static Margin of Stability? You'd also get a lighter stab, less stress on the boom and lower overall drag.

Just thinking as I watch along with our build....

Tony


Title: Re: Minislick -Build-
Post by: Alan Cohen on March 30, 2010, 12:20:44 PM
Got the bearing done. It wasn't too bad after a few years of not making one. I made a video of the process and will post it when it's done simmering at YouTube.

Make a pigtail bearing video: http://www.youtube.com/watch?v=IAnm1gXUyx4

Here's a pic of slicing the motor stick and installing the bearing. You need a straight piece of .010mw in place to get the alignment close. I usually use no down thrust, but I'm putting in 1º this time. The glue holding the bearing in is easily loosened with MEK and the final adjustments will be made with the prop installed.

So far I'm a little light at 162mg.


Title: Re: Minislick -Build-
Post by: Alan Cohen on March 30, 2010, 01:37:52 PM
Nice stuff so far Alan.
Out of curiosity (and ignorance on my part), but what about reducing the stab area to reduce some of the Static Margin of Stability? You'd also get a lighter stab, less stress on the boom and lower overall drag.
Just thinking as I watch along with our build....

That's a very good question, Tony. There is something about indoor guys and larger stabs and them generating more lift. I never got it. I always felt that the lift came only from the wing and the stabilizer did just that... stabilize. That said I'll probably just build a lighter stab this time and keep the size the same. Mostly because I don't feel like making new forms. <Bling> A light just came on. I do have the forms for my micro stick. It would be interesting to see the effect. Don't take much to unglue one and slap on the other.

Here's the forms for building both the Minislick and Microslick. I'll definitely build the smaller stab and see what happens. If it turns out to be a winner, I'll give you half my winnings, Tony.

Wing wood dimensions as per plan. .030" wide x .040" high, c-grain on top. I first stripped the .040" dimension off a very stiff, 6-7# density sheet of 1/8" balsa and then restripped the same piece to the .030" dimension. I made several so I could pick out the best one (and have back ups if necessary). It will not be easy to bend even wet. No soaking required, just a brush full of water at the radiuses. It's important to maintain tension as the wing spar is bent around the radii to avoid kinking. Not that a kink would affect performance, it's just bad form. I use a magnet to gently pinch the spar against the form and then glide the magnet and spar together around the curve.

Double glued the ribs and added the pre-cut TE. Ribs are the same dimensions and the spars.


Title: Re: Minislick -Build-
Post by: Tmat on March 30, 2010, 05:30:48 PM
Cool!

So what are the forms made from Alan? They look like card stock. Is that right?

I was thinking something like a 20 to 25% smaller stab, the micro looks like it's half the area? Should be interesting.

Quick question: How do you make the wing posts round? Is there an easy method?

Tony
-waiting for the cheque from the winnings... ;D


Title: Re: Minislick -Build-
Post by: Alan Cohen on March 30, 2010, 05:36:39 PM
Cool!
So what are the forms made from Alan? They look like card stock. Is that right?

I was thinking something like a 20 to 25% smaller stab, the micro looks like it's half the area?
Should be interesting.

The forms are .040" thick styrene sheet. It gives a smoother edge than card stock or matt board...better to release the outline.

Wing outline is done. Dry weight looks good. I want 90mg covered.


Title: Re: Minislick -Build-
Post by: lemuel on March 30, 2010, 07:18:31 PM
Here is a Video of my micro minislick...

http://upload.youtube.com/my_videos_upload?feature=mhw4

regards
Matthew


Title: Re: Minislick -Build-
Post by: ram on March 30, 2010, 10:03:14 PM
Try this:

http://www.youtube.com/watch?v=xtwEeEfP37M

I like how you talk to your planes as they fly! I've noticed a lot of people do the same.

Rey


Title: Re: Minislick -Build-
Post by: Alan Cohen on March 31, 2010, 07:42:34 AM
Here is a Video of my micro minislick...

Most excellent Matt. Does yours have the same uncanny way of seeking the most hazardous places to land. Mine loves bicycle spokes. I built my micro more as a test of the design. Anything that can fly that well with a 5" span will certainly do better at 7".


Title: Re: Minislick -Build-
Post by: lemuel on March 31, 2010, 07:58:41 AM
As a matter of fact, we have a hole in our glass cabinet about 1" x 2" and it did manage to fly into that SOMEHOW???? We also have a picture rail in the lounge room that it lands on frequently. I must make one of your ministicks. I think I might go for a stupidly light version. Then I will have two!! Yay.

regards
matthew


Title: Re: Minislick -Build-
Post by: Alan Cohen on March 31, 2010, 11:30:29 AM
I think I might go for a stupidly light version. Then I will have two!! Yay.

Ministicks are overbuilt at 430mg. I built a "stupid light version" a while ago. It was 179mg sans rubber. It flew on a single strand of .009" rubber and looked like a tiny F1D in flight. It just floated around my LR. I will build another one day. I think we officially dubbed them T.U.M.S, or, The Ultimate Mini Stick.


Title: Re: Minislick -Build-
Post by: Olbill on March 31, 2010, 03:42:05 PM
With a heavy boom I would need more decalage to keep the nose up, yes? I think my previous versions were in the neighbor of 5-6* decalage. I'm trying for 3* on this one and lets see what happens.

Nope. Rearward CG uses less decalage. Rearward CG also reduces static stability. Plug the numbers into Bernie Hunt's spreadsheet if you want to see the effects without spending flying time doing it.


Title: Re: Minislick -Build-
Post by: Alan Cohen on March 31, 2010, 03:46:18 PM
Nope. Rearward CG uses less decalage. Rearward CG also reduces static stability. Plug the numbers into Bernie Hunt's spreadsheet if you want to see the effects without spending flying time doing it.

D'oh!!! Of course Bill. What the heck was I thinking? Obviously, not much! I knew there was a reason I used the same 6.9# wood for both motorstick and tailboom. It helped with that nice nose-up attitude. Now I need to make a new tailboom...basswood I'm thinkin'. ;)


Title: Re: Minislick -Build-
Post by: Tmat on March 31, 2010, 06:00:55 PM
Nope. Rearward CG uses less decalage. Rearward CG also reduces static stability.

Yep, I agree. What about just moving the wing forward to move the CG back?

Declage and CG are entwined as we all know.

Tony


Title: Re: Minislick -Build-
Post by: Alan Cohen on March 31, 2010, 06:33:36 PM
Yep, I agree. What about just moving the wing forward to move the CG back?

I currently mount the wing about 1/4" forward of where you see it on the plan. Can't go much farther without the prop hitting the the LE, especially with 3º left thrust.

This time I think I will go with as light a prop as possible. I've made them as low as 50mg. 70mg is the right number to keep it relatively sturdy. This should help move the CG rearward. I usually fly it with CG at the rear wing post. I'll shoot for 105-110% wing chord this time.

The good news is this one is coming in maybe 50mg light of the 430mg minimum. I can stick the ballast anywhere I want to play with the CG.


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 03, 2010, 09:34:25 AM
OK, I stole a little time this morning to cover the flying surfaces.

First, to build the sub-rudder, by far the most important part of this design, I use one end of the stab form to get the curve.

Then add the straight pieces.

Now for the covering. Pic 3 shows the equipment. I like to use a spongy foam surface to roll out some OS Film. Yes, you can use PPP or some of the heavier films equally well on a ministick, but since I am the procurer and guardian of the main roll of OS Film, why not use it. The foam serves to keep the film from moving around while handling. I simply roll out the length I need, place a lipgloss coated frame on top (lipgloss side down of course), cut it free from the roll with an electric cautery and turn it over. Because the lipgloss is not a permanent adhesive, it allows for manipulating the film to remove, or at least even out, the wrinkles. To tight is not good; the balsa outlines cannot handle tension. I normally crinkle the film to help with this, but to be honest, I haven't done this in so long, I just plain forgot.

After a nice even, semi-taught surface is achieved, the outlines are lightly misted with Super 77 spray adhesive and and gently placed on the film. I run a finger all around the outline ensure good adhesion because the worse thing that can happen is the film releasing from the outline after it is trimmed. There is just no getting it back on.

Now, the fun part. Cutting the outlines free from the frame. There is just no way around this, an electric cautery is the way to go. When I first started, I used a piece of .010 music wire, repeatedly heating it over a flame and cutting film. You can cut about an inch or two at a time this way, but the edges of the film get blackened and if you get greedy and go for that extra 1/4" around a corner and the wire cools...yank...you're starting over again.

All surfaces are now free and ready for dihedrals. Later...


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 03, 2010, 09:40:31 AM
278mg so far. Too light. With 70-75 target weight for the prop, plus tissue tubes, wing posts and a little more glue to hold everything together, I'm thinking I'll be around 375mg all done. That will leave me 55mg of ballast to help manipulate the CG a bit. More than I wanted, but better too light than too heavy.


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 03, 2010, 11:50:32 AM
I made a little video on covering with light mylar film. It might be still brewing at YouTube.

http://www.youtube.com/watch?v=wTLIsItvwJk


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 03, 2010, 07:30:43 PM
Time to do the dihedrals. First, a small slice about halfway through the LE and TEs just outside the dihedral ribs. Then crack each slice trying not to separate the spars. Dip an .010-.015 piece of wire into a small drop of full non-diluted aliphatic wood glue and slide it into the joint. Then prop up the wingtips making sure everything is flat, square and the wingspan does not exceed the prescribed 7". Let dry completely while cutting wingposts and preparing for the propeller. Lastly, run a saliva soaked paint brush just outside the dihedral rib to remove the slack in the wingtip film.

Everyone that sees these little beasties for the first time always asks, after the obligatory "where can I buy one?", "how long did it take to make it"? I answer, "a couple of days", "But it took a couple of years to learn how."


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 04, 2010, 08:27:42 AM
Wing posts and tissue tubes.

Wing posts are not the place to try and save weight on an indoor model. I have a plank of straight grained 3/32" wood I save just for this purpose. It's about 12# density and strips easily due to the straight grain. First I stripped off an .035" piece with my Tyson stripper and then stripped that one to about .065". The dimensions are not critical since they will be used as the mandrel for making the tissue tubes.

First we need to cut an .030" x .040" notch for the LE & TE wing glue joint. For a secure joint, you want as many surfaces of the post touching as many surfaces on the wing, in this case 3 including the rib. You would prefer the high part of the notch not poking into the covering. A test fit never hurts.


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 04, 2010, 08:30:31 AM
Now for the tissue tubes. You need two thin strips of tissue and a little Duco.

I first tack a piece of tissue to the wing post and let it dry a bit. Then coat the entire piece of tissue with a thin layer of Duco and begin wrapping. I wait a few seconds for the Duco to flash off before removing the tissue tube. If you wait too long you will be starting again as the tissue will become a permanent part of the post. This is a good time to attach the LE tube to the fuselage. Don't loose the second one.

Those with a keen eye will notice I sanded away some of the motorstick behind the rear of the pigtail bearing. You cannot have enough room for rubber when you're putting a 15" loop in less than a 5" space.


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 04, 2010, 08:44:10 AM
Now comes attaching the posts to the wing. I still have my original wing post jig from my very first Hobby Shopper EZB. It has been modified to accommodate ministick wingtips. I through away all those nasty red-headed pins years ago, but still have these two for this jig. I have no idea why?

You want the LE post to be 90º in both planes. This jig really helps. If you want to see how it's built, refer to the article at http://www.indoorduration.com. Then go to Articles/Hobby Shopper Construction Guide. In my opinion, this article is a labor of love and by far the greatest gift to this part of the hobby.

Anyway, a picture tells 1000 words. This is how to wing posts are installed.

The rear wing post is installed at a slight angle which, when inserted into the tissue tube, will create some washin on the left wing panel. I want about 1/16 of an inch at the left dihedral rib. The final adjustment always seems to have to be made with the wing mounted on the plane, but skewing the rear post helps get things started. I'm hoping one day I'll get lucky and have a "Fonzie in the mirror" moment.


Title: Re: Minislick -Build-
Post by: Olbill on April 04, 2010, 01:13:39 PM
One of the most interesting things about this build is that there is very close to nothing in Alan's techniques that are like mine. It's amazing how many different ways intelligent people can come up with to have the same or similar end result. And of course the value is that when you're watching someone else use totally different techniques there will also be those moments where you say "That's neat ! I never thought of doing it that way."


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 04, 2010, 03:03:28 PM
Glad you're enjoying the build Bill. I posted this build to show others that have not ventured into the indoor duration arena that there really is no mystery to it. I never thought that other indoor builders would find it the least bit interesting. I assumed everyone did things the right way my way ;)

For me it's less a virtue of intelligence as it is laziness. You know what they say, if you what to find the easiest way to do something, ask the laziest person.

Here's my high-tech stab alignment jig. A tiny amount of starboard tilt and an eyeball for squareness.


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 04, 2010, 08:55:28 PM
I threw an old prop on to see what it looks like in the air. It needs a tad more washin on the left wing to level the flight a bit more, but otherwise it looks great. Here's a video of its maiden voyage... you might have to wait a few minutes to get it in HD.

http://www.youtube.com/watch?v=sJmnkC1tTtQ

As I feared, after adjusting the incidence to where it needs to be to get a nice floaty flight profile, it looks like there is several degrees of decalage once again. You'll see on the video just how fast it snaps back after bumping something. Oh well. I'll try it again after I weight it with the new prop and see how much ballast it needs and where I could put it.


Title: Re: Minislick -Build-
Post by: Tmat on April 04, 2010, 09:18:33 PM
From the side view it looks to have a lot of declage (wing LE is very high) so the CG is likely too far forward. Can you make a lighter prop? Or heavier stab or boom? Or just add some ballast to the rear.

Sure flies nice though!

Tony


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 04, 2010, 09:39:12 PM
CG is 1/8" behind the rear wing post without rubber. With rubber probably right at the rear post. You can see in the pic that it's still tail heavy when trying to balance on the rear post. This prop is 94mg bringing the whole thing to 410. The new one will be 70mg leaving 40 for ballast.


Title: Re: Minislick -Build-
Post by: Olbill on April 04, 2010, 10:09:24 PM
Just fly the way Romash does at Kent - put a Lakehurst wind on it and let it bang the ceiling. Then you'll be happy with the quick recovery! (or you'll get hung like most everybody else does who tries this idea)


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 04, 2010, 10:31:01 PM
I wish I had Rob's good fortune. Me, well mine found the ceiling fan on its very first flight! That's all you need to know about my luck in this hobby.


Title: Re: Minislick -Build-
Post by: julio on April 04, 2010, 10:38:53 PM
Your Minislick build became into a great tutorial Alan. Thanks for sharing your techniques, pics and videos included!

Bravo!

Julio


Title: Re: Minislick -Build-
Post by: Olbill on April 05, 2010, 12:51:52 AM
I wish I had Rob's good fortune. Me, well mine found the ceiling fan on its very first flight! That's all you need to know about my luck in this hobby.

Last year I hung my F1L on a record attempt, ballooned it off, and then it hung again on one of the lights before I could catch it. Scratch #1 F1L! The backup ship wouldn't cut it in a desperation last flight. I'm planning on bringing 3 trimmed models this year to try again.


Title: Re: Minislick -Build-
Post by: Art356A on April 07, 2010, 10:02:57 AM
I know this was treated on a different thread, and to my mind no firm conclusion was drawn, but I still can't understand why you people build more and more fragile props and then add nosewieght. Isn't it more sensible to make the prop a bit more robust? Or move the wing back a tenth or two?

And don't tell me about gyroscopic forces building from a prop that weighs nothing and is turning maybe 100 RPM. If such forces existed, they'd only work to the betterment of the flight pattern (but they don't exist).

Got my rubber cutter. I love it, but can't get the Ron White line about the sunglasses and the 27 inch color TV out of my head.

Art.


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 07, 2010, 10:18:11 AM
The issue on this model is that the CG is too far forward resulting in excess incidence to achieve a good flight profile. The light prop in this case is to move the CG rearward. Ballast will be added to the tail, not the nose.

It is possible my insistence on getting the model to fly "on the step" might be misplaced. Normally, to achieve best flight times on indoor models you adjust the incidence so the model cruises just below the point where it begins to stall and 'porpoise'. This slows the prop down and achieves a very floaty flight pattern. It also results in a very aggressive climb on ministicks. Great for Lakehurst, not Kent. Maybe we try for a little less incidence. It might hurt the cruise and/or descent, but also might help keep it out of the ceiling lights.


Title: Re: Minislick -Build-
Post by: Olbill on April 07, 2010, 03:40:18 PM
I still can't understand why you people build more and more fragile props and then add noseweight. Isn't it more sensible to make the prop a bit more robust?

I'm not sure who you are referring to as "you people". In most cases involving indoor duration models the entire model including the prop is built to be as strong as possible and still be at or under the minimum weight. Building an overly fragile prop and then adding noseweight would be ridiculous. OTOH reducing the prop weight in order to redistribute the weight (as Alan has done) or strengthen some other part of the model is perfectly valid.


Title: Re: Minislick -Build-
Post by: Art356A on April 07, 2010, 06:24:01 PM
"You People"... I think I first heard the phrase used by Rush Limbaugh; I don't exactly remember the context but if Rush used it it can only be a Good Thing. It's been more recently used around here by a CFII to refer to those of us who've shown no interest in flying IFR.

I use it, in this case, to mean super experts for whom I have huge respect, and on whose every word I hang.

a.


Title: Re: Minislick -Build-
Post by: craig h on April 08, 2010, 10:13:18 AM
You indoor fliers amaze me how you can build these models and make them fly so well! I being an outdoor rubber model flyer has always wanted to try indoor flying. I assume on your video Alan that you had used a torque meter to wind...I wished you could show the whole process of getting your bird prepared to fly in steps.

For me that would be most interesting...seeing your stooge so I would know what was needed...your torque meter and how to load the motor onto your model. I would think most new comers would also benefit from the details of preparing the model.

Thank you for the fine thread and I hope to see more...

Thank You Alan.... Craig h


Title: Re: Minislick -Build-
Post by: Tmat on April 08, 2010, 12:19:16 PM
I'll second Craig's request. I think I know what's involved, but I'd like to see how Alan does it too. ;D

Tmat


Title: Re: Minislick -Build-
Post by: Olbill on April 08, 2010, 12:32:43 PM
Here's my winding setup. I'll start a new topic to explain further so Alan can describe his methods here.


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 08, 2010, 01:08:56 PM
I've seen a lot of indoor winding stooges and I don't think I've ever seen two alike. I use the Cezar Banks torque meter made from the same ole plans that have been kicking around forever. http://gallery.scioly.org/details.php?image_id=2019 This one is set up for EZB and ministick with a max torque of .2"oz. Tim Goldstein has a wire calculator on his indoorduration.com site under Utilities for calculating how thick and how long a piece of MW should be. He also has a dial generator there for printing the face.

My set up is in the first pic. I made a foot and a wire stop for my Wilder Winder. The stooge is just two pieces of aluminum c-channel c-clamped to the table with a foot receptacle on the end fashioned from misc aluminum angle and flat stock.

My motor handling methods are a bit unorthodox. I'll make a video later and post it.


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 08, 2010, 01:19:18 PM
You indoor fliers amaze me how you can build these models and make them fly so well! I being an outdoor rubber model flyer has always wanted to try indoor flying. I assume on your video Alan that you had used a torque meter to wind... I wished you could show the whole process of getting your bird prepared to fly in steps.

Actually, for that video, and anytime I'm just trim/fun flying, I put one end of the motor on the winder, the other in my mouth, but don't tell anybody.


Title: Re: Minislick -Build-
Post by: Tmat on April 09, 2010, 12:28:58 AM
Alan,

What is the wire contraption mounted on the bottom of the brass main tube on the outside? Is it some way to release the tension on the meter after winding? The drawing you linked to for Banks' torque meter design is a bit too small to zoom in and see clearly.

Tony


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 09, 2010, 12:40:57 AM
Yes, there is a wheel collar on the front of the dial which acts like a knob/handle and another one at the rear of the torque wire with a small machine screw inserted. When the release wire is "in" it engages the machine screw, stops the torque wire from turning and displays the torque reading. When you pull it out it spins freely allowing a quick unwind of the motor.


Title: Re: Minislick -Build-
Post by: Tmat on April 09, 2010, 12:50:35 AM
That's interesting. Can you tell me how or why/when this feature would be used?

Tony


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 09, 2010, 06:16:47 AM
Hum... when someone comes up and asks you "how/why/when this feature would be used" while you're winding and you lose count and need to start over would be one situation. Achieving 15 minutes with a ministick involves over 4000 turns. Easy to lose count.

Also, the stooge is a good place to break in a motor. Winding to 80-90% max torque and letting the motor sit for 5 minutes and then rewinding is a good practice.

The alternative to the release mechanism is letting your winder unwind. But that's just extra wear and tear that's not necessary.


Title: Re: Minislick -Build-
Post by: Tmat on April 09, 2010, 12:27:01 PM
I see, thank you Alan. But don't you have a counter on your Wilder Winder that I see?

Tony


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 10, 2010, 03:40:06 AM
Yes, there is a counter on the winder, but it only goes up to 500 and then starts over. When winding 4000 turns that's 8 times around... or was it seven. ;)

Here's a vid of the release mechanism in action. The first unwind is using the release wire. It's basically just a wire spinning in between two thrust bearings. Not as violent as it may sound. The front indicator wire is 180º from the stop screw in the rear so if offers a bit of offset to help balance the wire. It is better that letting the winder handle spin since the handle is not balanced and vibrates pretty badly. You can see and hear that in the second half of the video.

http://www.youtube.com/watch?v=QJiwWS8Qf4I

Also, some close-ups of the torque meter. It's hard to tell from the pics, but those are two brass nuts soldered onto the side of the main tube.


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 10, 2010, 03:44:12 AM
More close-ups...

The base allows swiveling in two dimensions. It's a little more of a pain to make, but definitely worth it since the meter will always be square to the winder/motor.


Title: Re: Minislick -Build-
Post by: Tmat on April 10, 2010, 08:29:14 AM
Thanks Alan.

The video shows that the torque release is less violent than a handle release of the winder.

Tony


Title: Re: Minislick -Build-
Post by: lemuel on April 10, 2010, 05:57:13 PM
Allan, you sell select balsa sticks on your website. Any chance of selling the sticks for one of you mini sticks? super light that is...

regards
Matthew


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 10, 2010, 07:30:55 PM
The video shows that the torque release is less violent than a handle release of the winder.

Can't be a really good thing for the winder.

Matt, I might be able to put together a kit for you. Wing and stab spars are the same. Motor stick and tailboom are the same. Rib stock is .032 c-grain. Prop wood is .015" c-grain. How about enough wood for 4 planes for $15 including shipping down unda?


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 10, 2010, 08:55:50 PM
.


Title: Re: Minislick -Build-
Post by: Alan Cohen on April 10, 2010, 11:10:32 PM
4 proper Minislicks - some assembly required... ;)


Title: Re: Minislick -Build-
Post by: lemuel on April 10, 2010, 11:12:46 PM
Check your email Alan.

regards
Matthew


Title: Re: Minislick -Build-
Post by: jmetcalf on June 19, 2011, 01:09:18 AM
I am interested in building a canard ministick... is there a plan available?   Can the chord of the main wing be an AVERAGE width of 2.5" ( ie tapering from say 3.0" to 2.0") or must it be no wider than 2.5"?


Title: Re: Minislick -Build-
Post by: Alan Cohen on June 19, 2011, 05:59:07 PM
No wider than 2.5".


Title: Re: Minislick -Build-
Post by: Maxout on June 19, 2011, 07:05:28 PM
I don't know of any canard ministick plans...something tells me that given the ministick rules, it would be a little difficult, mainly becaue of the 5" motorstick limitation. It can be done, just won't be competitive.

Like Alan said, the rules specify 2.5"...no exceptions.


Title: Re: Minislick -Build-
Post by: Olbill on June 19, 2011, 07:59:49 PM
Here's a lesson in how to stretch the meaning of rules.


Title: Re: Minislick -Build-
Post by: jmetcalf on June 19, 2011, 08:44:07 PM
Thanks Bill for 'circular' mini-stick photo... always interested in alternative solutions


Title: Re: Minislick -Build-
Post by: lemuel on June 19, 2011, 10:03:48 PM
How cool is that! How does it fly old bill?


Title: Re: Minislick -Build-
Post by: Olbill on June 19, 2011, 11:32:31 PM
I didn't see it fly but Jim Clem finished 12th in 2001 with a time of 9:15. I assume it was with this model. How he got it ruled legal I'll never understand.


Title: Re: Minislick -Build-
Post by: Alan Cohen on June 20, 2011, 06:55:01 AM
I didn't see it fly but Jim Clem finished 12th in 2001 with a time of 9:15. I assume it was with this model. How he got it ruled legal I'll never understand.

Maybe because he finished 12th. And maybe because he's Jim Clem. It would have been interesting to see what would have happened if he won.


Title: Re: Minislick -Build-
Post by: Olbill on June 20, 2011, 08:28:49 PM
Good points! Maybe one of us should build one for USIC next year and see what Dave says at check-in.


Title: Re: Minislick -Build-
Post by: Alan Cohen on June 21, 2011, 06:53:47 AM
Someone would have to stand by with the video camera for that one! Dave's face would be priceless.


Title: Re: Minislick -Build-
Post by: Bruce McCrory on September 25, 2011, 10:50:01 AM
I heard Jim's concept was rendered illegal. Exceeds 2.5" chord.  Ellipsing into a stab, rearward, might save the annular aspect of the flying surfaces.
--Bruce


Title: Re: Minislick -Build-
Post by: jmetcalf on September 26, 2011, 04:00:21 AM
Can you explain 'ellipsing into a stab' please Bruce?


Title: Re: Minislick -Build-
Post by: THB on September 27, 2011, 07:00:46 AM
Not sure about ellipsing...  but that circle wing stuff has been done before...   :)
http://discaircraft.greyfalcon.us/World%20Disc%20Development.htm
Tim


Title: Re: Minislick -Build-
Post by: Ron_P on September 28, 2011, 07:58:12 PM
WOW, this is the 1st time that I had the chance to see an indoor model built! It looks like you choose your wood from regular sheets of balsa, sort of like Larry Coslick wrote in one of his articles.


Title: Re: Minislick -Build-
Post by: crashcaley on December 18, 2011, 01:36:47 PM
Alan, Thanks for doing this thread in easy to use format.  I am learning a lot.  I especially like the how to on applying mylar covering in your viddie.  And thanks for showing that electric heat cutting tool in the viddie.  I've been trying my first indoor model, trying to use an xacto knife and double edged razors that pretty much just destroy the mylar.  That tool will be a good investment in case I have the chance to do more indoor flying after Tustin.  Caley


Title: Re: Minislick -Build-
Post by: Alan Cohen on December 18, 2011, 08:54:26 PM
It's definitely a test of patience building this small, but it's more just a big shift in building techniques.

Building indoor models is all about building tools and jigs in order to handle tiny wood sizes and awkward coverings. The good news is once you have the jigs and a little practice, you can just crank out new models relatively quickly. When I fly a ministick in public I inevitably get the question (right after "where can I buy one?): "How long did it take to make it?" My answer is "about a week, but it took two years to learn how."


Title: Re: Minislick -Build-
Post by: crashcaley on December 18, 2011, 09:04:43 PM
Alan,  I can understand the length of the learning curve.  I am at the beginning of that curve when it comes to indoor models, most of which fly terribly, probably because I have so much to learn first.  Just wished to thank you for having this thread.  It sure helped.  Caley
 


Title: Re: Minislick -Build-
Post by: Bruco on December 29, 2011, 06:13:23 AM
Thank you for this excellent thread ! I must say I am learning a lot!
My last ministick was enormously overweight, at about .5 grams. I will read all that again and try to make a better one. I would also be interested in a followup, about the flight trimming.

Best regards,

Bruno


Title: Re: Minislick -Build-
Post by: Tapio Linkosalo on December 29, 2011, 06:25:43 AM
Now that this thread is brought up again, I have a question on "Minislick" layout: why both tip dihedral on the tailplane and a separate rudder? The rudder area of the model seems quite large (compared to other indoor models)? Is this to help the initial trim/stability of the model (as many Ministicks are prone to wild aerobatics right after launch on high torque...)?



Title: Re: Minislick -Build-
Post by: Alan Cohen on December 29, 2011, 11:36:59 AM
Now that this thread is brought up again, I have a question on "Minislick" layout: why both tip dihedral on the tailplane and a separate rudder? The rudder area of the model seems quite large (compared to other indoor models)? Is this to help the initial trim/stability of the model (as many Ministicks are prone to wild aerobatics right after launch on high torque...)?

You got it, Tapio. Ministicks are prone to barrel rolls on launch due to the high torque of the motor and a 7" prop on a 7" wingspan model. It makes launching very unpredictable.

With the subrudder, the Minislick will not turn more than 90* under full winds. It will usually do 3-4 very quick circuits at a 90* bank, not climbing or decending, and then start to level off and climb. It's almost eerie how similar every launch looks.

The tip dihedrals on the stab are just for aesthetics. It looks silly to me with a flat rudder.


Title: Re: Minislick -Build-
Post by: Tapio Linkosalo on December 29, 2011, 12:48:47 PM
Hmm. Have you tried yours without the tip dihedral? I have a model (well, would need a new set of wings after the last time it got hanged real bad) that has similar dihedral on the wing as yours, flat tailplane and underhung rudder (although smaller than in your model). It is just as bad as any Ministick I've seen at the start. As a matter of fact, I learned that reducing the prop pitch will help the initial stability problems, but of course that is not too good for the flight times then, as finer prop needs a thinner and longer motor.



Title: Re: Minislick -Build-
Post by: Alan Cohen on December 29, 2011, 02:15:03 PM
I have not tried it without the tip dihedrals, but I have tried it with a smaller rudder. All I can say is the size of the rudder is critical. It took a few attempts enlarging the rudder to get the right launch profile.


Title: Re: Minislick -Build-
Post by: Tapio Linkosalo on December 29, 2011, 03:15:04 PM
OK! Will try a larger rudder (but without tailplane D/H) for the next upgrade of lifting surfaces!


Title: Re: Minislick -Build-
Post by: Alan Cohen on December 29, 2011, 04:50:04 PM
OK! Will try a larger rudder (but without tailplane D/H) for the next upgrade of lifting surfaces!
At your own risk. ;)


Title: Re: Minislick -Build-
Post by: Bruce McCrory on February 06, 2012, 07:49:30 PM
Prop/rubber combo's are important to minis. I remember running one on .018" Tan II and the prop accidentally set at 20-something inches of pitch. The experience queue'd me to rubber thinner than what (.025's and bigger) everyone was using at the time. The tiplets shrank and I was doing great--no heeby-geebies-with .021" when Romash showed Brown how to wind up a .022", 14-minute motor.

All that to say: The tail dragger could probably shrink. Maybe a smaller section of rubber? Burn, or stretch off a little energy first? I always did better time in a rapid repeat (more turns) when running 5/99. 3/02 was supposed to have more energy.

I am still of the group that thinks polyhedral kills lift, slowly or rapidly, depending on how much is used. However, a new mini I am doing will try substantial polyhedral. My tips were always falling apart. And, for such a small area, tiplets are probably too draggy.


Title: Re: Minislick -Build-
Post by: Maxout on February 07, 2012, 10:46:02 PM
I am still of the group that thinks polyhedral kills lift, slowly or rapidly, depending on how much is used. However, a new mini I am doing will try substantial polyhedral. My tips were always falling apart. And, for such a small area, tiplets are probably too draggy.

My best ministick wing uses tip dihedral with tip plates. My testing has ground to a halt in an attempt to preserve the model for official flying, but its last quarter motor flight was 3:07, never reaching even 15' at any point in that flight. If I were to let it climb, it had another 30+ seconds in that motor.


Title: Re: Minislick -Build-
Post by: Bruco on February 13, 2012, 05:26:26 PM

Alan,

Please, could you possibly explain how you build a light Ministick propeller ?

My best effort so far weighs 105 mg, which is very much better than my previous attempts (rather above 130), but still very far from the weighs you quote. I think I would not be the only one interested in the answer.

Bruno


Title: Re: Minislick -Build-
Post by: Tapio Linkosalo on February 14, 2012, 01:14:59 AM
I made my latest prop from excess scrap of F1D motor tube wood. Seems perfect stuff for the application for me.


Title: Re: Minislick -Build-
Post by: Alan Cohen on February 14, 2012, 10:03:06 AM
Please, could you possibly explain how you build a light Ministick propeller ?

My best effort so far weighs 105 mg, which is very much better than my previous attempts (rather above 130), but still very far from the weighs you quote. I think I would not be the only one interested in the answer.

My Mini's always flew better with light props. 72mg is the goal. .011 5# wood cut at a 30* angle and 5.5# density prop spars that taper from .055 x .062 to .025 x .025 with a .010 MW hook. I used to build them at 90mg, but 72 is better.


Title: Re: Minislick -Build-
Post by: Bruco on February 15, 2012, 11:48:06 AM

Thank you very much for the info!

Yes, I understand that the wood used here is substantially thinner and lighter than what I used until now (0.015 thick balsa for the blades..). However, with blades that thin, what about crash-resistance ?
I mean that, as I fly my ministick in my living-room, the plane is  banging the ceiling very much, and sometimes hitting walls. It does not seem too hard for the fuselage, wings, etc, but I have already broken some props.

On the other hand, as my plane is too heavy, I must use a thicker motor (at least that is what I do...), which is not too gentle with the props.

Is a light prop as the one described supposed to withstand that kind of abuse, or is lightness necessarily reserved for the large rooms ? or is there something else entirely ?

Bruno


Title: Re: Minislick -Build-
Post by: Alan Cohen on February 15, 2012, 01:21:34 PM
Thank you very much for the info!

Yes, I understand that the wood used here is substantially thinner and lighter than what I used until now (0.015 thick balsa for the blades..). However, with blades that thin, what about crash-resistance ?
I mean that, as I fly my ministick in my living-room, the plane is  banging the ceiling very much, and sometimes hitting walls. It does not seem too hard for the fuselage, wings, etc, but I have already broken some props.

On the other hand, as my plane is too heavy, I must use a thicker motor (at least that is what I do...), which is not too gentle with the props.

Is a light prop as the one described supposed to withstand that kind of abuse, or is lightness necessarily reserved for the large rooms ? or is there something else entirely ?

Ah...and there is lies the rub. One of the big keys to indoor models especially is getting everything in balance. There is no point have a 70mg prop if the rest of the model weighs 2g. The prop should be in proportion with the rest of the ship.

Here's the video of my current one that I made right after I built it. As you can see it just bounces off everything. I have never broken a prop during flight. I've broken several trying to extricate the prop from in between bicycle spokes, it's default landing spot.


http://www.youtube.com/watch?v=sJmnkC1tTtQ


Title: Re: Minislick -Build-
Post by: Bruco on February 15, 2012, 04:00:34 PM
Thank you.

I'll keep that in mind and give up extra light props for the time being until i am able to build the plane itself much lighter, and to use a thinner motor.
I noted that you use rubber which is less than 0.023 wide, while with 0.025 my plane has short flights and lands with many many turns left. (I thus normally use 0.030). But it is hard to know where to start. I was tempted by the prop as most of mine are so much heavier than yours that it seemed a good place to start saving weight.  Maybe I am going to try to add small improvements, starting with the covering of the flying surfaces. I guess the way to go is still quite long. I am going to continue following building threads. This one has plenty of very interesting info. Thanks.

Bruno


Title: Re: Minislick -Build-
Post by: _shadow_ on February 19, 2012, 12:05:41 AM
Hi Alan,

Im new to indoor free flight and I find this guide to be very useful especially to a complete newb like me.

Thanks.

Regards


Title: Re: Minislick -Build-
Post by: green-man on February 19, 2012, 03:10:47 AM
Hi Bruno,

Are you trying to learn on your own? It's quite hard to do that. There are one or two very good indoor duration flyers in France, do you know them? If not, send me a private email and I'll let you have their addresses.

Nick.


Title: Re: Minislick -Build-
Post by: sgping279 on November 29, 2012, 10:13:38 PM
Hi everyone,
Im a newbie from Singapore and I hope I could get some advice on trimming the Minislick. I tried building it and it came out to be 0.550g. How do you normally trim your ministicks? For my current one it seems that it is a little nose heavy, it climbs fairly fast and easy but when descending it seems that it does not have enough torque to keep up, stalls and drops significantly in height. Angle of incidence is already quite steep, what more could I adjust so that the descent would be gentler or the reason has got to do with the fact that it is overweight?

Thank You
 


Title: Re: Minislick -Build-
Post by: Bruco on January 17, 2013, 04:46:28 PM
Hi sgping279,

In my limited experience, this is the effect of overweight. Lighter is very much better!

Bruno


Title: Re: Minislick -Build-
Post by: albisko on February 01, 2013, 02:19:24 AM
any my LRS :)


Title: Re: Minislick -Build-
Post by: Alan Cohen on February 01, 2013, 10:48:31 AM
Hi everyone,
Im a newbie from Singapore and I hope I could get some advice on trimming the Minislick. I tried building it and it came out to be 0.550g. How do you normally trim your ministicks? For my current one it seems that it is a little nose heavy, it climbs fairly fast and easy but when descending it seems that it does not have enough torque to keep up, stalls and drops significantly in height. Angle of incidence is already quite steep, what more could I adjust so that the descent would be gentler or the reason has got to do with the fact that it is overweight.

You need to trim the incidence for the cruise, not the climb. If it is stalling after it is done climbing then you need less incidence. Lower the leading edge of the wing a bit at a time until it almost looks like it wants to stall under cruising power, but doesn't.


Title: Re: Minislick -Build-
Post by: lcordes on February 02, 2013, 03:10:14 PM
Alan, I just finished my 5th MiniSlick and am still overweight at 450mg.  My problem is in the prop, which (the best one) weighs 132mg.  I'm using tissue tube hub with plug-in prop spars and don't have any idea how to make a single piece prop spar and glue the blades to it.  Are there any videos that you know of which might give me some guidance on this?

LeRoy


Title: Re: Minislick -Build-
Post by: dslusarc on February 04, 2013, 01:20:30 AM
Here is my new Ministick. 400mg as seen in photo. I need to add a little weight.

Don


Title: Re: Minislick -Build-
Post by: albisko on February 04, 2013, 05:20:12 AM
very nice!

we have national category (little bit large LRS) N50 (new fifty cent)
span 11" and other restrictions


Title: Re: Minislick -Build-
Post by: adanjo on February 04, 2013, 09:01:22 AM
LeRoy san,
Your prop is not very heavy.
I am using tissue tubes for all of my indoor props except A-6. Adjustable pitch and re-bakable blades are  big pros.
My ministick props weigh 112 to 130mg.
If you want to make it lighter, you should use lighter and/or thinner wood for the blades.

Don san,
Your wing post seems very thin. How about using 5mg for the posts?

Good flying, Aki


Title: Re: Minislick -Build-
Post by: Alan Cohen on February 04, 2013, 09:43:26 AM
Alan, I just finished my 5th MiniSlick and am still overweight at 450mg.  My problem is in the prop, which (the best one) weighs 132mg.  I'm using tissue tube hub with plug-in prop spars and don't have any idea how to make a single piece prop spar and glue the blades to it.  Are there any videos that you know of which might give me some guidance on this?

LeRoy

I just paged through the build and can't see where I built the prop. I must have had a few laying around.

I just moved and everything is in boxes so I can't add to the thread right now. I can tell you my standard prop weighs 90mg. I've made 70mg props and they work better...less incidence required to get the nose up.

My prop spars are 5.5# density: .062x.062 tapered to .020x.020. Two 3.5" square tapers attached at the prop shaft by a scarf joint. No tissue tubes.


Title: Re: Minislick -Build-
Post by: dslusarc on February 04, 2013, 11:21:10 AM
Don san,
Your wing post seems very thin. How about using 5mg for the posts?

Aki,

The wing post are .035 x .050 6.5 pound wood. What size do you use?   

Since I just built a prop here is some info I had on my prop. Blades are from .010" sheet 4# density and I used 5.6# wood for the spar that is .060" round tapered to ~.030" round. .010" music wire shaft. The blades were 60 mg for the pair and the complete prop is 92mg. It was formed on a 3.15" diameter jar at 18 degree angle and is set to 17" pitch.

Don



Title: Re: Minislick -Build-
Post by: adanjo on February 05, 2013, 12:33:39 AM
Aki,

The wing post are .035 x .050 6.5 pound wood. What size do you use?   

Oh, they are thicker than I had guessed watching your photo.
My posts are 1.2mm =0.047" dia, almost the same cross section as yours, and about 35 to 40mm long.
No wood density data, maybe 7-8 lbs.
Here in Japan, we will hold a Ministick contest for the International Postal Contest on 28 March at a 9m ceiling gym.
Enjoy ministick, Aki


Title: Re: Minislick -Build-
Post by: lcordes on February 05, 2013, 12:30:08 PM
Thanks a lot guys.  I guess I have to dig up some 0.010" sheet for the blades and taper the spars more.  If I could get down to 90 or 100 mg I would need to add weight too.  For the life of me I still can't figure how you drill a prop spar and fasten it to the blades at the proper angles for the pitch without having the spars already mounted on the blades.  Maybe next one, but I will try making a lighter prop and see how I do.

LeRoy


Title: Re: Minislick -Build-
Post by: Alan Cohen on February 05, 2013, 01:33:20 PM
Thanks a lot guys.  I guess I have to dig up some 0.010" sheet for the blades and taper the spars more.  If I could get down to 90 or 100 mg I would need to add weight too.  For the life of me I still can't figure how you drill a prop spar and fasten it to the blades at the proper angles for the pitch without having the spars already mounted on the blades.  Maybe next one, but I will try making a lighter prop and see how I do.

I pierce the prop spar with the sharpened prop shaft while it is still straight and then bend it to a 90* angle with pliers while it's still in the spar. I then pull the bend flush with the front of the spar and when it looks good I hit it with a drop of CA. Then I'll spin if afterwards to make sure its's true and make adjustments as needed. It's only .015 wire. The hard part is bending the rubber hook after the spar is glued, but I've kind of gotten used to doing it that way.


Title: Re: Minislick -Build-
Post by: ykleetx on February 05, 2013, 02:57:34 PM
LeRoy, the Hobby Shop EZB article describes how props are made this way.  Check it out


Title: Re: Minislick -Build-
Post by: Olbill on February 05, 2013, 10:33:13 PM
Or you can stay with 2 piece props which is the smarter way.<G>


Title: Re: Minislick -Build-
Post by: lcordes on February 09, 2013, 06:55:52 PM
2 piece props are certainly the easier way but will have to check out the EZB article per Kangs suggestion, haven't seen it since I started in indoor when I thought that it was way too much work for me then.


Title: Re: Minislick -Build-
Post by: ykleetx on February 09, 2013, 07:50:02 PM
LeRoy,

As others have pointed out, your prop isn't heavy.  If you are comfortable with a two-piece prop joined together with a tissue tube, I would stick with it.  Certainly, take a look at the Hobby Shop EZB article to see if it can teach you something worthwhile.

Recently, Don posted two photos of how he attaches the prop blade to the prop spar, and they are revealing:

http://www.hippocketaeronautics.com/hpa_forum/index.php/topic,13367.msg99715.html#msg99715

The photos are in replies #54 and #56
(http://www.hippocketaeronautics.com/hpa_forum/index.php?action=dlattach;topic=13367.0;attach=88361;image)(http://www.hippocketaeronautics.com/hpa_forum/index.php?action=dlattach;topic=13367.0;attach=88365;image)

I do the 2-piece method.


Title: Re: Minislick -Build-
Post by: Getnold74 on March 13, 2013, 01:44:26 PM
Re: Message #24

Your photo showing the removal of the film slack after putting in the dihedral shows using a saliva moistened brush. Are you overlapping the film back on its self and the saliva is the adhesive?

I am not having any luck at all with this procedure. I am a newbie and my first attempt at using this procedure has not been successful. Any tips?

Can you provide the mfg and brush number?

Thanks.

Everett


Title: Re: Minislick -Build-
Post by: Tapio Linkosalo on March 13, 2013, 02:00:08 PM
The trick is to use sufficient liquid; if you cannot spit enough (hehe!), try some solvent. I often simply add some acetone from the nose-bottle used to loosen glue joints. On light models the capillary and then air pressure is enough to keep the film folded, on heavier models I add a tiny amount of contact cement to the fluid. With deliberate amounts of fluid the film just folds onto itself; just like magic!



Title: Re: Minislick -Build-
Post by: Getnold74 on March 15, 2013, 05:41:20 AM
Thanks.

Will try again.


Title: Re: Minislick -Build-
Post by: Alan Cohen on March 15, 2013, 04:48:54 PM
The proper paint brush makes it easier. Use a tapered brush like the one at the top of this pic. This allows enough saliva to fill the brush and travel the distance across the chord. And the taper will actually draw the film together as it passes over the slack.

If your saliva isn't sticky enough, sip a little orange juice before you lick the brush.



Title: Re: Minislick -Build-
Post by: lcordes on March 28, 2013, 04:51:47 PM
Alan - regarding prop forming - I see Don S. uses a 3.15" diameter form.  What do you recommend for form Diameter?


Title: Re: Minislick -Build-
Post by: Alan Cohen on March 29, 2013, 09:03:56 AM
I've never use cylinder forms. I use prop blocks, 10" pitch IIRC.


Title: Re: Minislick -Build-
Post by: ram on April 05, 2013, 10:40:37 AM
Don san,
Your wing post seems very thin. How about using 5mg for the posts?

Aki,

The wing post are .035 x .050 6.5 pound wood. What size do you use?   

Since I just built a prop here is some info I had on my prop. Blades are from .010" sheet 4# density and I used 5.6# wood for the spar that is .060" round tapered to ~.030" round. .010" music wire shaft. The blades were 60 mg for the pair and the complete prop is 92mg. It was formed on a 3.15" diameter jar at 18 degree angle and is set to 17" pitch.

Don



Don,

Is your prop pitch really 17" and full flaring?  Mine is 12" pitch with the spar about .25" from TE of blade.  I haven't had a chance to fly it yet, so don't know how it will work.  Is yours typical?  I may need to make a new prop.

Rey


Title: Re: Minislick -Build-
Post by: lcordes on April 06, 2013, 10:46:56 AM
Don, your .010 blades - are they one piece or glued up like Easy B blades ?

LeRoy


Title: Re: Minislick -Build-
Post by: JoseMiguel on December 08, 2014, 05:25:34 PM
Hello Alan. I am new to the forum. Very good all your interventions, and very instructive.
The plan indicates minislick rubber section 0.0225 ". This thickness is 0.057 millimeters. Is this information correct?