ORIGINAL: Quorneng
Servo are a pet issue of mine.
Why do people use such big ones!
It is quite common to use a servo with a torque rating that could easily lift the whole weight of the plane.
I doubt if a full size 3D aerobatic pilot could lift even a tenth of the planes weight with one arm!
Even a fully loaded B29 (120,000 lbs) still only had one man arm power but to be fair it was considered hard work to fly.
On this basis even a 10lb 150mph plane should not actually <u>need</u> more than micro servos.
I am not for one minute suggesting such a dramatic step but with a bit of sound engineering and aerodynamics it is perfectly possible to use smaller servos which can easily be installed close its surface, thus improving mechanical efficiency and saving weight. There are also advantages in reduced current draw, lighter servo cables, smaller batteries etc.
Rant over!
Full size A/C with mechanical control linkage often use various methods to reduce the force needed to move the control surfaces.
(Tabs that move, offset hinge points, parts of the control surface ahead of the hinge point and so forth.)
Such things are less common on models. Control surfaces are also often oversized on models.