Special-Purpose Servo Types and Sizes

Servo motor advantages and comparisons are already discussed now its time to discuss Special-Purpose Servo Types and Sizes.
While the standard-sized servo is the one most commonly used in both robotics and radio controlled models, other R/C servo types, styles, and sizes exist as well.

Quarter-scale (or large-scale) servos

 are about twice the size of standard servos and are significantly more powerful. Quarter-scale servos are designed to be used in large model airplanes, but they also make perfect power motors for a robot.

Mini-micro servos

 are about half the size (and smaller!) of standard servos and are designed to be used in tight spaces in a model airplane or car. They aren’t as strong as standard servos, however.

 

Sail winch servos 

are designed with maximum strength in mind, and are primarily intended to move the jib and mainsail sheets on a model sailboat.

 

Landing-gear retraction servos 

are made to retract the landing gear of medium- and large-sized model airplanes. The design of the landing gear often requires the servo to guarantee at least 170° degree rotation, if not more (i.e., up to and exceeding 360° of motion). It is not uncommon for retraction servos to have a slimmer profile than the standard variety because of the limited space on model airplanes.