$100 EDF Scratch Build Contest Flying Wing
#1

Hi Everyone
For the contest, I will be Scratch building a 70mm Flying wing, I never Hot wired a Wing before from Foam, so this will be a learning Experience for me, Wish me luck
The wing will have a 40" Wing Span, winglets at the tip, Spanning both on top and bottom of the wing, and a launch/Skid on the bottom in the middle, The Skid and Winglets should keep the bottom part of the EDF off the ground, as the EDF will be in the center line of the wing rather than just laying on top of the wing, I am making the Pattern for the wing so i can hot wire the foam, The wing will have about a 35 Degree Sweep, the power system will be a 2839-3000kv motor, 60 Amp ESC, 4 cell lipo, 2200 mah 30C, 70mm EDF, 5 Blade Fan, 2-9 gram high torque Turnigy Servos, the control surface will be made from Formed Balsa Aileron Stock, Thats the Idea anyway
Take care and have fun, Chellie




Last edited by CHELLIE; 10-09-2014 at 10:49 PM.
#4





#5

Made a paper pattern for the Formica template, this will be a symmetrical wing Cord, I Just Traced my Shoe Sole For the Pattern
LOL, Just Kidding, I got it off the net, and made it a little bigger and Thicker, as I want to bury the lipo and esc into the wing to keep it clean for Subsonic Flight 




#6

The wing will look like a cross between these 2 wing Styles, I belive one is a 45 degree sweep and the other is a 30 degree sweep Wing, my wing will have about a 35-37 degree sweep. I will have to use the TLAR method 


#7

My Foam Came in Yesterday, Sooooo I am going to Draw out the Wing on the Foam to see how it will Look, Hmmmmm Not to Shabby
Here are a couple of Pics, Now I just need to get my Hot wire set up, make the Formica pattern and Start Cutting Foam 



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#12

Well, I guess I better get Off My Big Behind and Start Building
My EDFs and BSI Glue came in the Mail about 30 mins ago
Off to Hot wire the foam wing Now, Wish me luck, as this will be a first for me to hot wire a foam wing
Take care, Chellie




#13

I Epoxied a paper pattern that I made to a piece of Formica, now I have to cut it out and sand it and drill a few holes in it, so i can stick some long nails in the pattern to hold it to the foam, the pattern will be my guide for the hot wire to cut the foam with, I watched some You Tube videos on how to hot wire cut wings, I think I can do it too
I am Not Afraid to try anyway 


#16

Here is the Formica pattern with holes drilled in it, Dang, That Formica is tough to sand, I cut it close to size, then sanded it, took 2 sheets of 100 grit sand paper to get it to shape and smooth and about 1 hour of sanding
its done anyway
will hot wire the Foam tomorrow after I go Flying
Take care, Chellie



Last edited by CHELLIE; 10-18-2014 at 11:10 AM.
#18

Chellie, I have no experience with foam cutting but I do understand how heat effects foam. I was wondering, Why formica for the templates? Why not some 1/8" Plywood? Some material easier to work with, shape and sand. That hot wire is going to go through that foam so fast it will barely brown a wood template let alone damage it. Or am I wrong or missing something?
#19

Chellie, I have no experience with foam cutting but I do understand how heat effects foam. I was wondering, Why formica for the templates? Why not some 1/8" Plywood? Some material easier to work with, shape and sand. That hot wire is going to go through that foam so fast it will barely brown a wood template let alone damage it. Or am I wrong or missing something?



The guy in the video is using a inside pattern Guide i am using a outside pattern guide.
[media]http://www.youtube.com/watch?v=R0ZCnR_g6ZU[/media]
#21

Yep formica wont melt and the wire slides smooth across it while cutting through foam . I have a old wire cutter made from a larger american flyer train transformer and it worked great . I would cut out a honey comb pattern in my pattern birds wings to make it lighter then cover the wing with thin balsa sheets . It did nothing for me to compete in pattern flying except make it lighter for vertical manuvers and keeping speed up going vertical back then was half the battle. Good luck on your build Chellie !
joe

#22

Thank you Joe
I have a Marx Train transformer, it works good on my smaller hot wire cutter, hope it is strong enough to do a wing cut, if not, I have an Adjustable 12V, 30 Amp motor speed controller, that I can hook up to a car battery to cut the wing out with, I think that should do it, if the Train transformer does not work,
DC MOTOR PWM SPEED CONTROL 30A MAX 12V / 24V 100 Hz


DC MOTOR PWM SPEED CONTROL 30A MAX 12V / 24V 100 Hz