Thread: Discussion Skywalker 168cm FPV plane
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Old Jun 09, 2011, 07:08 PM
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Originally Posted by cmanley_nl View Post
I'm pretty sure I can move the CoG back and solve the problem that way but then I'll create another problem and that is that the Skywalker will no longer automatically pull itself out of a dive. Based on the dive tests I did I like the CoG where it is. I think lowering the angle of the motor will be the solution.
Lowering the angle of the motor will make the problem worse, not better, as you're
putting the thrust line even further from both the center of mass, and the
largest producer of drag, the main wing. The thrust line on a high mounted pusher is tipped up,
specifically to reduce that effect.

I have my CG a little behind 30mm behind the servo wire slot, and my SW is almost
dead neutral on and off the throttle, at any speed. The only time it pitches over
a little is if I'm low and slow, and try to go to full throttle really quickly.

If you don't have a throttle->down elevator mix (not an uncommon mix) then
your symptoms, as described, are indicating a tail heavy plane (CG too far back).

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