does elevator or rudder need more servo power?

[Bob Chiang]

Hi all,

I'm finishing up an electric glider, and happen to have two different servos available. Should I use the more powerful one for the rudder or elevator?

[Ollie]

The rudder needs more torque than the elevator. Compared torque of chord, area and max deflection. If the ground loop grags on the rudder, the servo gears can be over loaded.

[green66]

Should I use the more powerful one for the rudder or elevator? I assume that doesn't imply that the less powerful servo is a "cheapie" or suspect unit. Unless your plane doesn't have ailerons, i.e. it uses rudder alone for turning, the elevator will be the most critical function since pitch control generally can't be compensated as well as failure of a rudder or aileron servo. In short, don't put a servo that you have any doubt about, with respect to either its reliability or torque capability, on the elevator.

[Bob Chiang]

Thanks for the replys.

Green66: The model has only rudder, elevator, and throttle controls ( see this thread for the model http://tinyurl.com/56t86 ). The servos I have are a Hitec HS-55, and a GWS Pico standard. In my experience, they are both reliable so I'll plan to install the HS-55 on the rudder.

-Bob