What Size and Strength for Servos ?

[jmelzer]

I am doing an electric conversion project and got to wondering what servos I should use. The plane is a 60 sized sport model. AUW should be about 6.5 pounds. The plans of course call for standard size servos. I would like to use the lighter and smaller servos that I have available, and mount them closer to the elevator and rudder.
Now the question: Is there a rule of thumb regarding servo size and strength and the corresponding control surface size? Perhaps a torque vs. area relationship?
Best, Jay

[astroboy]

Try this one:

http://www.multiplexrc.com/calcservo.htm

--and allow for friction, binding, and some extra for safety.


Jeff

[jmelzer]

Very helpful.
Thanks, Jay

[gkamysz]

Do consider gear strength if needed. Small servos make plenty of torque but shock loads can be a problem.

Greg