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Author Topic: Ministick and microstick - trying to get back into indoor!  (Read 9262 times)
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Olbill
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« Reply #100 on: January 08, 2018, 12:23:46 PM »

3-4 in-oz might be appropriate for a Wakefield (not something I know anything about). In order for you to compare your torque with others then you need to calibrate your torque meter in real in-ounces. A normal A6 launch torque for my models in a low ceiling is around .1 in-oz - depending of course on the actual site configuration. In a high ceiling like the Kibbie Dome it might be .35 in-oz or more if I can get more torque in the motor without breaking it. So it sounds like the units on your meter are off by about a factor of ten.

As others have said if you don't care about comparisons with what other fliers do then you can use any units you want to. I think this is an especially bad idea for someone starting out. Why not take advantage of the knowledge that others are willing to share?
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Flyguy
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« Reply #101 on: January 08, 2018, 12:38:00 PM »

That was just a typo, forgot the period, haven't used the torque meter for eons and I forgot that a reading of '2.5' is .25 oz-in, also the zero was a little off and I have to remember how to reset it (it's a Geauga torque meter). But I just got started and was more focused on experimenting with different props, I'll start paying attention to the torque next time, need to get my 'indoor legs' back. Wrt what others are doing, I think I'm in the range of what I've seen reported, but I need some time to catch up on that, particularly since A6 is new to me (and I'm supposed to be reading stuff for my job, not for airplanes!)
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Flyguy
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« Reply #102 on: January 09, 2018, 01:52:48 PM »

Phew, finished a new mini for tomorrow's flying, first photo, and a second A6 so that I still have one to fly if the first one gets eaten! With the additional practice, I got the OS film on a little smoother, I also have a new prop with increased blade area for the mini, we'll see what that does, I like experimenting with different props. Will pay closer attention to the torque/motors this time!
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Olbill
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« Reply #103 on: January 09, 2018, 03:26:58 PM »

Another thing that will help your A6 is a flaring prop. The blades for an A6 are too stiff to do much bending so you pretty much have to make the spar do the flaring. You can get a little bit of flare in the blades by orienting the grain parallel to the spar and using the lightest and weakest wood you can find for the blades. The more blade area you have in front of the spar the more flare you can get. My blades are 100% ahead of the spar.

My prop spars are about .020" thick. One is bamboo and the other is bass. It may have just been luck but these first two props are the only ones I've ever needed in over 10 years of flying A6.
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Flyguy
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« Reply #104 on: January 09, 2018, 04:10:24 PM »

Thank you, that's interesting, I have some bamboo skewers that I can sand into a nice spar, I also have some bass, I'll give it a try! Is your spar .020 round/square?
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leop
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« Reply #105 on: January 09, 2018, 08:51:02 PM »

And try to find a sheet for the prop blades that is nearly pure a-grain.  The cross-grain stiffness of c-grain balsa is much more than for a-grain.  This helps the blades to flex and flare.  Also, less dense wood means less stiffness and more flare.  You can look on the net for pictures of the two grains.  Remember that every piece of balsa can show both grains on a surface.  It all depends on how the balsa is cut.

LeoP
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Olbill
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« Reply #106 on: January 09, 2018, 09:59:11 PM »

Thank you, that's interesting, I have some bamboo skewers that I can sand into a nice spar, I also have some bass, I'll give it a try! Is your spar .020 round/square?

My plan says the spar is .020" x 060". Where it attaches to the blades it tapers to the same thickness as the blades (1/32"). I actually use the same props for all ceiling heights with only pitch changes if needed. My motor size also doesn't vary very much for different ceiling heights.

If you'll research all the other A6 threads on HPA there is a lot of information available.
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Flyguy
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« Reply #107 on: January 09, 2018, 10:48:26 PM »

OK, I took a look at it, thanks, it looks like the shaft goes through the .020 part (?), I have some numbered drills and it shouldn't be a problem, but that might be tricky for beginners or some of our older modelers. I see there are some lengthy A6 threads that I haven't had a chance to read yet, right now I'm thrilled I can fly again and am simply focused on getting a few things built to fly for the next session.
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Olbill
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« Reply #108 on: January 10, 2018, 01:27:03 AM »

The prop is built in two identical pieces. The spar on each pice is about 3 1/8" long. The butt ends of the spars are overlapped so that the finished prop diameter is 6". The prop shaft is sandwiched between the two prop spars.

Here are pictures of my two props. The first picture is one blade from the prop with the bamboo spar. On this prop the spar goes all the way to the outside end of the blade.

The second picture is a view looking down the prop shaft of my prop with basswood spars. For this one I stopped the spar about halfway out on the blade to save weight.

The third picture is the two halves of the bass spar prop before they were joined.
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Re: Ministick and microstick - trying to get back into indoor!
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Flyguy
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« Reply #109 on: January 10, 2018, 03:51:26 PM »

Thank you very much for those details, very helpful, I'll give it a try. I have to say though that I have somewhat mixed feelings because it seems to be pushing the rules a bit, which were clearly intended to keep everything simple - a small prop, flat blades, 1/32" balsa, etc., but if it's legal it's legal.

I was able to keep all the planes below 35' today, but the girders start at 31' and I had some bad luck and ended up losing both my new ministick and my first A6, ouch, that's four planes lost in 3 flying sessions! I kept my new A6 safely below 30' so I got in some nice flights and am getting the feel of it, was able to start paying attention to props/torque/etc. Back to building, need some more planes for next week!
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OZPAF
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« Reply #110 on: January 10, 2018, 05:40:46 PM »

Boy that place is a real model eater Larry.  Smiley You fellows flying there may need to hire a "cherry picker' mobile hydraulic crane to retrieve models Smiley

John
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Olbill
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« Reply #111 on: January 10, 2018, 05:43:53 PM »

Thank you very much for those details, very helpful, I'll give it a try. I have to say though that I have somewhat mixed feelings because it seems to be pushing the rules a bit, which were clearly intended to keep everything simple - a small prop, flat blades, 1/32" balsa, etc., but if it's legal it's legal.

I was able to keep all the planes below 35' today, but the girders start at 31' and I had some bad luck and ended up losing both my new ministick and my first A6, ouch, that's four planes lost in 3 flying sessions! I kept my new A6 safely below 30' so I got in some nice flights and am getting the feel of it, was able to start paying attention to props/torque/etc. Back to building, need some more planes for next week!

There's nothing about my model that in any way violates or stretches the rules. Which of the items you listed do you think are questionable?
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Flyguy
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« Reply #112 on: January 10, 2018, 07:22:32 PM »

Given that the whole structure is 1/16" sq. balsa, rounded at the wingpost mounts, and ribs 1/16 by 1/32, I originally thought that this restriction held for the prop spar as well, though you're right, it simply says 'wood' (so I guess other types of wood could be used for the other structures as well). The prop is the biggest hurdle for many people - for ex., we have an older flyer who built a beautiful P18, I've been trying to convince him that he could easily build an A6, but he's worried about the prop, I showed him today that he could simply take 1/16" sq., round it, and glue on the flat blades, which is probably as simple as you can get for starters, so that was encouraging. Seems that limiting the prop size to 6", limiting blade thickness to 1/32" (would be easy to sand them), and limiting blades to be flat (easy to wrap them on a jar) were all intended to simplify the prop as much as possible, to level the field a little for beginners, doesn't seem that the props were intended to be flaring props (otherwise why not simply allow for thinner blade balsa or larger props?). Not criticizing anyone's plane, particularly yours Bill which is really really nice and a fantastic flyer, and I think the flaring bass/bamboo spar is a very clever and appealing idea that I want to try as well, so I'm simply noting that it doesn't appear to me to likely have been thought of and and in the original spirit of the event (to keep everything at the beginner's level). But maybe it was, with a different view from how I'm seeing it, I don't know. Not a problem, it's still a really fun event and that's all that counts!
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Flyguy
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« Reply #113 on: January 10, 2018, 07:32:40 PM »

Boy that place is a real model eater Larry.  Smiley You fellows flying there may need to hire a "cherry picker' mobile hydraulic crane to retrieve models Smiley

John

Tell me about it, I've only gone 3 times and already have 4 planes up there! Frustrating part about today is that I did a good job of keeping the height below 35' all day but the rafters curve and are lower in parts and I had bad luck and landed inside them with both my mini and A6. However, I had several flights after that with my new A6 where I dialed in 30' a little closer (fear is a good motivator) and so I had several nice rafter-free flights to end the day. I'm hoping to break the 'at least one lost plane per session' pattern next week, let's see. In the interim, I already started another A6 and will probably build another mini over the weekend as well! good thing they build fast
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mkirda
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« Reply #114 on: January 10, 2018, 10:22:14 PM »

Given that the whole structure is 1/16" sq. balsa, rounded at the wingpost mounts, and ribs 1/16 by 1/32, I originally thought that this restriction held for the prop spar as well, though you're right, it simply says 'wood' (so I guess other types of wood could be used for the other structures as well). The prop is the biggest hurdle for many people - for ex., we have an older flyer who built a beautiful P18, I've been trying to convince him that he could easily build an A6, but he's worried about the prop, I showed him today that he could simply take 1/16" sq., round it, and glue on the flat blades, which is probably as simple as you can get for starters, so that was encouraging. Seems that limiting the prop size to 6", limiting blade thickness to 1/32" (would be easy to sand them), and limiting blades to be flat (easy to wrap them on a jar) were all intended to simplify the prop as much as possible, to level the field a little for beginners, doesn't seem that the props were intended to be flaring props (otherwise why not simply allow for thinner blade balsa or larger props?). Not criticizing anyone's plane, particularly yours Bill which is really really nice and a fantastic flyer, and I think the flaring bass/bamboo spar is a very clever and appealing idea that I want to try as well, so I'm simply noting that it doesn't appear to me to likely have been thought of and and in the original spirit of the event (to keep everything at the beginner's level). But maybe it was, with a different view from how I'm seeing it, I don't know. Not a problem, it's still a really fun event and that's all that counts!

Flaring props can actually be really difficult to build well. Most of the time they tend to flair unequally when done with balsa alone.

The A6 prop Bill came up with - using readily available materials - makes this trivial. At least for A6.
The basswood spars flair equally.

The only difficult part is finding very light a-grain wood.
However a quick email to Nick Aikman and you can have some show up at your door in about two weeks.
I'd recommend something like 3.6#.

A6 props built this way are very simple to replicate as well. They are also more rugged than balsa ones. Even better for beginners.

Regards.
Mike Kirda
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Flyguy
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« Reply #115 on: January 11, 2018, 02:38:58 PM »

Thanks for that tip Mike, I'm really looking forward to trying out the prop, always nice to learn something new! I have some precious 4lb balsa (from Nick) that I can use, but I didn't even know something less than that was available, holy cow, I guess I'll do another order!

Should note though that I still think it starts to take it out of the 'beginner' category, but that's arguable and let's just leave it at A6 is fun! I also think this is why P30 is enormous fun and is popular - even beginners can make a competitive plane (of course the pros will still usually win because of their high flying knowledge and ability!).

The parents of the girl I helped with her SO last time asked where they could get all the materials. The great part is that you can get almost everything locally - I told them you can get 1/32 and 1/16 (and 1/8) sheet and strips at local art shops (and I've found sheets with indoor density sections at those stores), so there's the whole structure, you can get piano wire at music and art stores, lube and all the glues you need at hardware and drug stores, and some garbage bags work as nice covering, so they were thrilled about that. They asked about getting the tan rubber that came with the kit locally, and I told them that I don't think you can do that, but they can easily order it online, but they were still a little bummed about that part.
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adanjo
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« Reply #116 on: January 11, 2018, 09:00:50 PM »

My prop spars are about .020" thick. One is bamboo and the other is bass.

.020" is thinner than 1/16". Is it legal?
The original intention of A6 was a model that could be easily built by using thick wood only.

Aki
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dslusarc
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« Reply #117 on: January 11, 2018, 09:22:05 PM »

1/16 sq min does not apply to prop , motorstick or tailboom.

"24.4  All wing, stabilizer and rudder wood  including wing posts shall be 1/16” square
wood minimum, except ribs shall be 1/32” X 1/16” minimum. Posts may be rounded
in the area of the mounting tubes."

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ram
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« Reply #118 on: January 11, 2018, 09:25:15 PM »

24. A-6. For Event (222 )
24.1. General.
Except for the specific rules which apply directly to A-6, the rules for Free Flight Indoor Rubber, Hand Launched Stick model shall apply.
24.2.
The model shall be rubber powered and covered with paper or commercially available plastic; no microfilm allowed.
24.3.
The total maximum projected wing area shall be 30 square inches. There is no restriction on the stabilizer area.
24.4.
All wing, stabilizer and rudder wood including wing posts shall be 1/16” square wood minimum, except ribs shall be 1/32” X 1/16” minimum. Posts may be rounded in the area of the mounting tubes.
24.5.
The motor stick shall be from solid wood of 6” maximum length measured from the front thrust bearing face to the front of the rear hook.
24.6.
The propeller shall be 6” maximum diameter with flat blades from balsa no thinner than 1/32”.
24.7.
The minimum weight of the model shall be 1.2 grams without rubber motor.
24.8.
No special materials such as boron, carbon fiber or foam are to be used.
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Flyguy
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« Reply #119 on: January 13, 2018, 11:55:41 AM »

OK, I decided to try a bass spar prop. I always make all my prop spars in one piece, just my preference, so I did it that way. Bass is .032 in the center and it wasn't that difficult to pierce it with .012 wire. It's easy to go in dead center, the trick is coming out on the other side - I did four of them and one was no good, but the other three came out dead center so it's not too hard. After I got some raw spars with nice centered holes, I sanded them to about .020 at the tips, also sanded the 1/16 to about .050 and a slight taper. Then I inserted the wire and just hit it with a drop of CA, picture below. Actually came out lighter than my balsa props (but that might put me a little under 1.2 total) and I can feel that it can twist much easier than the balsa spar. I made two, one a little thinner than the other. Flew nice in a living room test, let's see what happens on Wednesday (flying session).
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leop
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« Reply #120 on: January 13, 2018, 05:39:35 PM »

Take a careful look that the pictures of Bill's props.  The grain runs parallel to the prop spar.  This allows for minimum stiffness in the blade and maximum blade flex.  This way there is more flare and more flare is usually better for lower sites.

The pictures for Flyguy's most recent prop show the grain of the blades at an angle to the prop spar.  This makes for stiffer blades.  The angle can be used to tune the flare but for lower sites, more flare is often better.  Of course, one can have so much flare that the prop does not work well even after the torque has decreased but, flying indoor is a "change what is needed" sport.

LeoP
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Flyguy
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« Reply #121 on: January 13, 2018, 06:18:12 PM »

I'm an old EzB flyer from the sixties and that's how I usually did the grain, force of habit. I also thought that all the flexing would be due to the spar, I didn't think that (relatively thick) 1/32" balsa would flex at all (and I ran out of 4lb, 4.5lb is the next lowest I have), but I'll give it a shot if you say it does, I have a third prop under way and I'll put the grain parallel this time, we'll see how that compares to the other two props on Wednesday.
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Flyguy
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« Reply #122 on: January 13, 2018, 09:58:16 PM »

OK, here's one with the grain parallel to the bass spar (this one is closer to .020 thick, and is .050 at the center and tapers towards the tips). will be interesting to compare.
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