Thread: Build Log MSComposite Swift II
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Old Sep 27, 2011, 03:44 AM
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Firepower
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North Brisbane, Australia
Joined Mar 2010
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Quote:
Originally Posted by TooSLow2Care View Post
Firepower,
Good Call on making sure i have my thrust angle set up properly before mounting the motor plate.

i'm actually waiting for my motor to arrive in the mail... but in the mean time we can talk physics and P-Factor just for giggles and so i can see what effect if any is has on a Northrop Grumman inspired Fuselage-less aircraft.

In pusher prop applications, sighting from the tail forward along the fuselage, and the propeller spinning counter-clockwise. The torque effect is up and to the right (toward 1:30 on a clock face), but the motor and torque are AFT of the CG, so the effect to the nose of the airframe is down and to the left (toward 7:30). To compensate for that, the motor thrust line must be compensated up and to the right of the nose (again, when viewed from the tail forward along the fuselage).

So a projected vector of the motor’s shaft will pass up, over your left shoulder for a counter-clockwise pusher setup.

And a projected vector of the motor’s shaft will pass up, over your right shoulder for a clockwise pusher setup.

I generally use about 2deg offset lateral thrust & about the same or less to angle the motor in the vertical component.

cheers,
Brian
Too much information. Just joking. I'll put it simple.

Firstly normal people (just joking again) have the prop going the other way. Looking from the back the prop turns clockwise. So in the attached photo the prop is turning clockwise from the rear but I have turned the motor MUCH more than it is suppose to be just so that the angle can be seen easily. I guess the same applies to a normal pylon plane and a flying wing.

I just glued the mount down flat on the wing and hoped the manufacturer got the angle up and down correct. For gluing the mount use THICK THICK THICK CA. My motor angle from left to right is perfectly straight and it does not seem to be a problem. With my fast motor I can go slow close to the ground and put on full power and it goes perfectly straight which is great.
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Last edited by Firepower; Sep 27, 2011 at 06:21 AM.
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