After a summer of misguided progress (apparently 3D printing was a terrible idea) and a busy school year, I decided to rebuild the plane and finish my project for my final high school project. Below are link to a condensed version of the presentation I gave, a time-lapse video of the build process and a flight video. Feel free to message me for details of the process or build.
Presentation:
https://docs.google.com/presentation/d/1qH7Sh3f_3Re3_vYbHrYAd1oMooiMFaM3Qlp4VSF-jtU/edit?usp=sharing
Flight Video:
https://drive.google.com/file/d/0B01p2a45VFilTU9ZV0o4cHk0OHc/view?usp=sharing
Build Video:
https://drive.google.com/file/d/0B01p2a45VFilSDNVOEdFTVJvSm8/view?usp=sharing
Comments
Looked like you were close to getting it flying. Amazingly tough center section! Put the wings back on. It is worth another try.
I find that having an autopilot in aircraft(even if it is just manual flight control) with a ground station logging the telemetry helps a lot in debugging an airframe.
Lovely looking plane.
The issue on takeoff on the maiden flight looks like a classic tip-stall, where the air stalls on one wing only with the result as here. It is usually unrecoverable unless you have a lot of height. Tip stall is a problem that particularly affects high aspect ratio wings at low speeds, especially those with ailerons. If you freeze the video just before the crash, you can see the aileron hard down which is often where the condition starts, since the wing needs to work harder than it can sustain. Commonly a tendency to tipstall is addressed in the design by subtle changes to the wing including twisting the wing and changing the wing section along the span. Also using more up than down aileron can help as well as raising the speed of take off and more gradual climbout
Ouch I spit out my coffee seeing that crash video! Wasn't expecting it! 99.9% sure it's excessively tail heavy. Thanks for posting!
Loved your build video.
Looked like something went wrong with the aileron controls to me.
I noticed in the build video you tried a gas engine, what was that and why did you decide to go electric?
Not a bad looking design to me, but it looks like the CG is too far forward (Wing maybe could have been forward more relating to fuselage.)
I personally would have used a wing with a longer chord and possibly a slower, higher lift airfoil.
NACAA 4512 is a very good medium and low speed highly efficient cruising airfoil, lousy upside down, but very good characteristics and efficiency at a variety of speeds when upright.
For high school it was an incredible achievement, it would have been amazing at the college level.
Best Regards,
Gary