Originally Posted by
Roelof
Get a set of small hairbands. They are a bit fuel proof and do work perfectly.
Be sure you have a smooth servo. Some standard plastic gear servo's are hard to turn by hand so a simple spring or rubber band will not work either.
A digital servo is
a lot smoother and easier to rotate without power than it is with a standard servo. Standard servos take a lot more rubber-bands/springs to overcome its resistance.
You can get decent digital servos for a very low price (depending what you look at) online from hobbyking.