So many choices for servos. How do you know whats best for your plane>?
Most planes have their recommendations for servos, but sometimes these
recommendations may be over kill and not clear on the torque and speed.

Is there a formula>? Some chart that explains which servo to use where>??

I have many planes , from hi wing trainers to large warbirds.
As you know. outfitting these planes with servos can get very expensive.
And I would like to minimize that expense.
So I only want to use the servo that is necessary and not overkill it with $$$.

Thanks for your input.
(GK) PAIN!

I am not aware of a written guide as to what servo to use for what application. Most manufactures list on the kit or ARF servo suggestions. If the plane is designed for 3 D or is getting into the bigger size planes, you will need to get bigger and better servo's. If your war birds are over the normal 60 size plane, I would upgrade all my flying surface servos. Good Luck, Dave

Ditto, if you're flying 40 - 60-size sport planes, Standard servos are plenty

Back when I was building SPADs, they had a formula for torque requirements depending on the square inch of the control surface times a predetermined number. I can't remember what the numbers are but I think it was something like 1 for trainers, 1.5 for sport planes and 2 for 3d planes. So if you had one servo for the elevator and the total size of the control surface 40 square inches then you would need 40 ozs for a trainer 80 ozs for a 3d model. But that was a SPAD with a grand total of $200 invested, not $2000! It would be nice to know how the manufacturers determine what servos a plane needs.