RE: What surface do you put the strongest servo on when talking about 3D planes and 3D flying
Simple. In general the order is..
1) RUDDER
Longest chord, large area, and minimal counter-balance, which adds up to the worst mechanical advantage against the air.
2) Aileron
About same area as rudder on many 3D planes but narrower chord, better leverage against the air than rudder.
3) Elevator
Small area, smaller chord than rudder and usually counterbalanced.
That's my $.02