Twin Boom Scratchbuild v2

by Jeffrey Saelee | May 10, 2012 | (6) Posted in Projects

Twin boom scratchbuild with Dollar Tree foam (depapered), AX2306 2000kv motor, 1300mAh 3S, 40A ESC (way overkill, but it's all i had lol).  At first it failed because of instability, weakness of foam, and of course, pilot error....but when I had it tweaked out, it flew like a dream....it was my 2nd scratchbuild, after my original twin boom http://www.youtube.com/watch?v=iIK_2fsfzdQ

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COMMENTS

Jake Wells on May 11, 2012
Way to go Jeremy! For only being in this a year and a half you're doing some cool stuff. Thanks for posting!
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Jake Wells on May 11, 2012
Opps sorry I ment Jeffery.
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Jeffrey Saelee on May 21, 2012
LoL, Thanks!
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V_Smith on May 12, 2012
Wow! Good job with the build! Have you thought about putting spares in the wings? It might help get rid of the wing load.
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Jeffrey Saelee on May 21, 2012
Thanks, yeah I added a carbon spar after the first few failed flights (oh hey, FFFF :D)
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azgar on May 12, 2012
I love this "hands up" move thy do when You pull up.
I have had one of theese "flexible wing" planes myself.
I think You could cover lover surface of the wing with Scotch tape.
But right thing to do is a profiled wing.
It's easy if You make lower skin, upper skin glued together on leading and trialing edges and a vertical foam longeron to make space between skins.
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Jeffrey Saelee on May 21, 2012
Basically a KFm-3 airfoil right?
I used a KFm-2...
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azgar on June 16, 2012
No, I meant like a real airfoil.
The top skin bends to a curve. Bottom skin bends a bit too, but it's not that relevant.
Try two strips of paper, 4" and 5" wide, for instance. Then glue the long sides together. The longer strip will bend into arch. If You'd put a vertical strip or two inside, You'd be able to fix a curvature.
The same thing can be done with foam too.
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Jeffrey Saelee on June 26, 2012
Oh Okay :D
And there's ExAir's Armin wing, too :D
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azgar on June 26, 2012
Indeed!
I was trying to remember the name but...
The only difference is in Armin wing the longeron is horizontal multilayer. I've made two vertical walls.
IMHO it's the same or little better on rigidity and a little less weight. And more control on resulting airfoil.
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Jeffrey Saelee on June 26, 2012
OK, Yeah I see :D
Genius XD
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schraut5 on May 10, 2012
Cool design! But your wings are way too weak. You should add a few layers of that foam you use to the wings to help stiffen them up, then I bet this plane would be perfect
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Jeffrey Saelee on May 21, 2012
Yeah, I did add a carbon rod after the first few flights...although it wasn't as stable. But a few more tweaks and it was flying like a dream!
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adrian.virnig on May 10, 2012
it looks like there is still an insane ammount of wing flex when just flying straight and level... i would advise using a carbon spar accross the wings just to keep them more level.
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Jeffrey Saelee on May 21, 2012
Yeah....I added a carbon fiber rod after a few flights, and it greatly reduced the flex--but made it not quite as stable....but I got it to work, and it flew great until its demise by nosediving into the ground at 75% throttle after I lost sight of it for a couple seconds behind a silo :D
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HigherFlyer420 on May 10, 2012
Looks like a great start, but it seems as though the wings are far too flimsy. As im sure you already know, a carbon spar would really help the loss of energy through twist and flex. :) Keep it up!
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Jeffrey Saelee on May 21, 2012
Yeah....After the first few flights I added a carbon fiber rod and it definitely helped--although it wasn't as stable.
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coffeebean56 on December 5, 2012
Try leaving the paper on.

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Jeffrey Saelee on December 5, 2012
Yeah i'm gonna try that if i do another Dollar tree foam build....:D
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Twin Boom Scratchbuild v2