Electirc Flying Wing..I NEED HELP!!!!!

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TheKid
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Electirc Flying Wing..I NEED HELP!!!!!

Post by TheKid »

This goes out to all the flying wing guys in combat, i need a little help with an electric flying wing that i made.
If you get Model Aviation, there was an article about them in the most recent issue of a wing made of egg crates.
I made mine with fan fold foam, but it looks the same.

Anyways, my problem is that when i go into a turn, the plane does this weird bouncing motion. It almost seems like it is stalling, but it dosen't snap out of the turns. I don't know much about wings so i was wondering if this is a problem with balance point or anything like that.

Any help would be nice.

PS, anyone with kids learning how to fly, it is actually a pretty sweet flying plane, for a first combat plane to practice with maybe. I started with a CD motor that puts out 22 oz of thrust at 11.1 V, but i now switched to a 34 oz thrust CD motor...So i hope that helps my bouncing turn problem, more power always helps right [:D][:D][:D]
slam
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Post by slam »

brian

too much power is just enough....

i saw that article. i don't have it in front of me (i threw it away) but i remember some of the planes that were shown.

first thing that comes to mind is the verticle stab. is it big enough and far enough back from the c.g. probably real easy to test by just taping an extension on the existing verticle.

the other thought i have is wing flex. i didn't read very carefully, did the wing have any stiffener? might be changing with the flex in the turn.

let us know what you find out.

they did look extremely easy to build and not bad to fly. i definately agree with the use of fanfold. the trays seem too much work. i like fanfold even though the "onion skin" is a bit of a pain to work with.

slam
TheKid
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Post by TheKid »

Yes slam, i do have a stiffener. In the first on i have a 2.5 inch wide balsa doubler glued to the bottom of the wing, in a turn the is no flexing, so i think its holding up right. the second one that i am almost done with has a carbon rod for a brace, i think that will be better and lighter.

Also, the stab is a good size, its about the size of a 2610 verticle. It stretches from the middle of the wing all the way to the back.

When my pit boy gets home i'll have him show me how to post pictures and i can show it off.

Once again, whats happening is that its lerching through the turns, and it also does that on landings.
Rabbit Leader
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Post by Rabbit Leader »

Pit boy???!!! Man, that's just so wrong...[:D]
Lee Liddle
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Post by Lee Liddle »

Brian, the wing is stalling and recovering, repeat, repeat. I would say that you are slightly nose heavy and have to use too much pitch control to get it to turn. If you move the cg back a little, you will need less elevon movement to get it to turn, and the wing won`t stall. When you have to move the elevons too much it causes the airflow to be screwed up on the back part of the wing, causing the oscillation.
TheKid
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Post by TheKid »

Thank you much lee, i suspected that was the problem.
From my experience with gliders the balance point of a flying wing has to be much further up the that of a conventional plane. Is there a general rule, like 30% or something like that?

Right now its 2 inches back (thats what the plans said, and it has a 10.5 inch root chord) So should it be more like 2.5" or even more then that?
Lee Liddle
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Post by Lee Liddle »

I`d say just move it a little. Try 2.125". If that`s better, try 2.25", but I doubt if you`ll want it any further back than that.
adamdb
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Post by adamdb »

For CG on flying wings I usually start with 15% and move back from there.
sgilkey
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Post by sgilkey »

guys, this little plane flies pretty sweet! Glides like a brick, though, which seems to reinforce the tail-heavy diagnosis. these would be a blast to combat with, i might have PBG Jr. build me one so I can kick his butt! PBG signing out.
RH
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Post by RH »

Hey pit boy, let's get on with the pic postin instructions so the kid can show us what he's got [:D]
TheKid
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Post by TheKid »

Ok, thhe PBG and i got the pictures uploaded. This is the first of the designs...it is exactly how the plans in MA say to make it, except that it has a full body to cover up the battery and such (less drag)
Image
This image illustrates the balsa spar, which slam asked if there was wing flex. This one does have a minor amount, but the second design has no wing flex due to the carbon spar
Image
And this is the one that i plan on finishing today, it has more sweep in the leading edge, slighhtly more aileron area, and the carbon rod.
Image
I plan on taking thhe 34oz thrust motor off thhe old one and putting it on the new plane to help benefit the stiffer wing. I think we own a high 20oz thrust motor for the old one, because we only have but one battery that can take the current draw of the bug motor.

this really is a fun plane to have around, it easily out performs the 3696, but then again it is light (i would guess like 13-15 oz) without the battery and it has a strong motor.
The motor is from Balsa products, its teh 2408-12 i think, it costs around 25 dollars, cheap knockoff esc, 1500 mah battery, and 2 blue arrow servos with a receiver, so it is a pretty inexpensize plane to feild as well, for anyone that wants something to mess around with. Its almost manueverable enough to fly in your front yard (like up and down the street) but i wouldn't chance it. A little league feild would be more then enough room
sgilkey
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Post by sgilkey »

Hey Dork, I just noticed you're landing on the ESC, can ya move that topside good buddy? PBG out.
Ben Morrow
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Post by Ben Morrow »

I don't care who ya are, now that's funny![:D][:D] Good one Scott...

Brain, Good looking planes keep the reports coming.[8]
Ben Morrow
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Post by Ben Morrow »

Brian,
What type glue are you using on these? If a person were to combat these little guys seems the damage might be light even if ya do mid-air. If ya do damage something (Plane)the cost sure wouldn't be much.

Looks like FUN!
TheKid
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Post by TheKid »

Well ben, on the first one i glued the balsa on with hot melt glue, but on the one with the carbon rod i used Polyurethane glue. The one with the rod was stiffer, but if you don't have rods laying around the balsa would work just fine.
They recommend 1/16 inch balsa for the spar, but i used 3/32.
Yeah, i think they would be a lot of fun to combat, they fly about as well as our Zagis, but it is much faster.

PS, for those that care, i weighed the second plane that i made and finished. The plane with gear weighed 6.8 oz. And then when you count that there is going to be 6.1 oz of battery (3 cell 2200 mah pack) it should be pretty light with 30+ oz of thrust
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