September 29, 2008

Why does my electric RC plane have a downward angle on the prop?

When viewed from the side "wings level" the prop is about 20 degrees down faceing. It flys just fine [wings level] and the manual says that the down angel is correct (I guess I'm not the first person to think it was damaged in shipment ), but it doesn't give any reason why.

Just wondering.
Thanks
Shawn
It flys level (or almost level) the angle of attack is no where near as steep as the down thrusting prop angle.

Thumbs up to Marvin! Model aircraft have the engine mounted with negative angle to help control the angle of attack. Almost all RC aircraft are WAY overpowered compared to a real aircraft of that type. It would be almost impossible to keep the plane from climbing, even with full down elevator, if the engine mount wasn't pitched down during installation.
You would need to re-rig your elevator to compensate for the thrust angle, and doing that would increase drag and slow your plane down.

If you don't believe me, reinstall the engine mount so that the propeller is vertical and try to fly it.

Also, RC engines are often mounted at an angle to the right, to help overcome torque and 'p' factor, which I won't go into…

Here's a link: http://www.rcaerobats.net/thrust_angles.htm

Filed under Electric RC by Ray

Spread the Word!

Permalink Print Comment

Comments on Why does my electric RC plane have a downward angle on the prop? »

September 18, 2008

Myshuno383 @ 8:17 pm

probably to make the wind flow correctly over the wings to give it lift.
References :

Mike M @ 8:18 pm

Sounds like it's just the particular design of the prop.
References :

Marvin: aka "The Man" @ 8:18 pm

Because the tail hangs low during flight and this gives the wings an upward tilt. The prop is aligned to this flying angle. 20 degrees seems a bit excessive. It's probably not that steep.
References :

September 19, 2008

threesheave @ 6:12 am

Thumbs up to Marvin! Model aircraft have the engine mounted with negative angle to help control the angle of attack. Almost all RC aircraft are WAY overpowered compared to a real aircraft of that type. It would be almost impossible to keep the plane from climbing, even with full down elevator, if the engine mount wasn't pitched down during installation.
You would need to re-rig your elevator to compensate for the thrust angle, and doing that would increase drag and slow your plane down.

If you don't believe me, reinstall the engine mount so that the propeller is vertical and try to fly it.

Also, RC engines are often mounted at an angle to the right, to help overcome torque and 'p' factor, which I won't go into…

Here's a link: http://www.rcaerobats.net/thrust_angles.htm
References :

Leave a Comment