Please help

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Iflyplanes
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Please help

Post by Iflyplanes » February 24th, 2019, 2:25 pm

Hi people of the forums! I have had a continuing problem with each glider I build; they all end up doing the same flipping motion after I attempt to launch them. I am not using a kit, but I used the plans for the plane from

http://www.amaflightschool.org/diy/how- ... e-olympiad

I need help, since the competition is next week. I would like to perfect this problem fast. Please help!

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Re: Please help

Post by waffletree » February 24th, 2019, 3:57 pm

Iflyplanes wrote:Hi people of the forums! I have had a continuing problem with each glider I build; they all end up doing the same flipping motion after I attempt to launch them. I am not using a kit, but I used the plans for the plane from

http://www.amaflightschool.org/diy/how- ... e-olympiad

I need help, since the competition is next week. I would like to perfect this problem fast. Please help!
when i started flying my glider, it would always flip backwards. if that's the case, just add small clumps of clay or putty to the nose of the glider to balance out the weight until it stops flipping. you only need to add a tiny bit at a time. you can start with an estimate by placing the middle of the glider's wing on your finger (so the fuselage is perpendicular to your finger), the add clay/putty based on that. then start testing it to get it even closer to what you want.
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Re: Please help

Post by bjt4888 » February 24th, 2019, 4:52 pm

I fly,

If by flipping, you mean rolling, I would suggest you inspect the wing and the stabilizer to be sure that there are no unintended warps or misalignment. 1 mm of warp or misalignment can make a big difference. Warps can be fixed by twisting the wood in the opposite direction while heating with your breath till you’ve warped in the opposite direction some. After sitting for a few hours, your twisting work will untwist some and hopefully you’ll have a flat surface. Misalignment can sometimes be fixed by breaking joints and rejoining correctly.

Or, if misalignments or warps are severe, it’s easier sometimes to just build a new glider using care (measure carefully, cut wood and joints with perfect alignment, draw parts templates using graph paper, etc.

If “flipping” means pitching nose up or nose down, then the fix is completely different.

Describe “flipping” in much more detail and we can provide better assistance.

Brian T

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Re: Please help

Post by Iflyplanes » February 24th, 2019, 5:07 pm

To Brain T:

When I say flipping I mean thet whenever I launch the plane, the nose pitches up, while the entire plane spins in a circular motion while remaining level. Without the rotations, I can fly the plane.

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Re: Please help

Post by bjt4888 » February 24th, 2019, 5:27 pm

Are you banking the airplane when launching?

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Re: Please help

Post by bjt4888 » February 24th, 2019, 5:57 pm

I am guessing that when you say “spinning in a circular path” you are referring to the helical flight path of the climb portion of the glider flight. Google “helical path/images”. A typical ELG climb flight path under low ceiling is 180 degree helical.

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Re: Please help

Post by Jdh3 » February 24th, 2019, 6:30 pm

Iflyplanes wrote:Hi people of the forums! I have had a continuing problem with each glider I build; they all end up doing the same flipping motion after I attempt to launch them. I am not using a kit, but I used the plans for the plane from

http://www.amaflightschool.org/diy/how- ... e-olympiad

I need help, since the competition is next week. I would like to perfect this problem fast. Please help!
Any chance you have a video you can post and link? It makes it much easier to see your problem.

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Re: Please help

Post by DatSciolyBoi » February 27th, 2019, 7:44 pm

You should put some ballast and put it on the tip of the nose, then adjust the center of gravity so that it is around the center of the airplane.
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Re: Please help

Post by Maxout » February 28th, 2019, 7:49 am

A video of the flight pattern would help a lot. Also, I've found that you can do 95% of the flight trimming by throwing the model horizontally by hand. A good hard, straight throw should cause the model to fly straight for a while, then gradually pitch up and turn to the right, slowing to glide speed. Don't worry about clay until you get that pattern. Clay is only for trimming the glide.

As an example, here's the trimming process I used for a plane that frankly was a bit of a pain to trim (still ended up being my second best performing 2018/19 ELG so far, coming within 1 second of my best time ever for that site):
https://www.youtube.com/watch?v=MuNag5fH_EI&t=5s
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