Thanks... and my research into this subject indicates that you are correct...,

HOWEVER.... as I have learned from studying this ... the mechanical advantage of the system is another factor... for instance:

with a one inch servo arm and a two inch control surface horn, there is a 2 to 1 mechanical advantage... therefore, the force applied to the control arm would be doubled..., e.g., a 1 inch servo arm with a 160 oz-in servo torque and a 2 inch control horn would result in a force of 320 oz-in on the control surface....

Granted this 2 inch control horn would reduce the degrees of control surface to half of the servo arm movement... e.g., if the servo arm moves 60 degrees (30 degrees in each direction from center) then the control surface's movement would be limited to 30 degees (15 degrees in either direction from neutral)....

My overall point in my trying to understand the physics of these systems is that ... I think the hobbist buys too much servo power... spurred on by the "merchandising" of the servo manufactures...

For instance... if on a specific plane, the builder wants 160 oz-in torque on an elevator half and that 15 degrees of throw in either direction from neutral is acceptable... then basically a wide variety of servos, servo arms, and control horn lengths are available.

Two choices might be:

Choice A: 160 oz-in servo; 1 inch servo arm; 1 inch control horn ... servo cost (approximately) = $100

Choice B: 80 oz-in servo; 1 inch servo arm; 2 inch control horn ... servo cost (approximately) = $40

I think most giant scale builders/pilots would opt for Choice A... thinking the 160 oz-in servo is the best.... and spend $60 more and not get any more benefit in torque at the control surface.... BOTH CHOICES PRODUCE 160 oz-in of torque on the control surface...

What happens also is that builders/pilots put these big torque servos on and with longer servo arms (1.25 inches) and shorter control horms (or move the control horn linkage closer to the control surface) to get the "big" surface throws.... then use the ATV (or end point adjustment) feature of their transmitters to reduce the surface throw to what is required... essentially spending perhaps hundreds of $$$ for excess servo strength... in an airplane....

.... am I right .... ?

Larry