Motor Angle and Thrust Vectoring Experiments

by franck | May 22, 2012 | (16) Posted in Just Fun

Can you guess what motor angle would make this plane fly best? Upthrust? Downthrust?

I could not figure it out so I added a thrust vectoring system to be able to experiment (and have some fun).

A close view of the thrust vectoring system is here:

Do you have any explanation for the result?


colorex on June 11, 2012
Great experiment!

Though I'm personally lost as to why you got the best results...
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spencer on June 4, 2012
Nice video. I would guess up thrust would put more air over the tail surfaces. That may help controlability. That's just my stab in the dark though.
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Nattyreeves on June 14, 2012
I think the reason that the plane pitches down on takeoff is because the motor is above the lifting surface. the wing creates drag making it slower than the motor which pushes itself down and towards the front, also this would make it harder for the plane to pitch up too because the plane would be pushing against its own motor. I've had trouble like this where i have mounted the motor above the lifting surface of a delta wing and it has plummeted to the ground. so I'm guessing that when you angle the motor to give a little upthrust it counters the effect of the motor wanting to push the plane down. cool plane BTW :)
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Jim Fox on July 20, 2012
I've always wondered why my Bixler and other pusher planes like it have so much downthrust angle to the motor. I notice the hairy few seconds during a hand-launch where the Bixler pitches down until it gets some speed. I was thinking of getting a new foam body set for my Bixler as it's getting pretty dinged up. Before I transfer all of the mechanical parts to a new foam body I think I'll try chopping the motor mount to give it some upthrust and see if it improves anything. I wonder if they angle the motor the way they do to get prop clearance.
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Flight4Life on June 11, 2012
Very nice video. I think the effect of vectoring changes depending on distance from the cg. As your prop was (probably) very close to it, the upthrust would be most useful pushing the air into the stabilizers. If your prop was all the way back (like on the Parkzone stryker), the vectoring experience should be different.
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stonekap on June 11, 2012
Really great video! Thanks for posting.
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Luka Carl on June 11, 2012
I always thougt so too. But why can we see an obious downthrust angle in pusher planes like bixler, easystar etc.
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sailorJohn on July 14, 2013
Wings look pretty flat without a great deal of lift , try a Ft or Armin wing with the test and post the results before I start my build ( tired of breaking props and bending shafts)
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Motor Angle and Thrust Vectoring Experiments