I know what servos do, and what they are supposed to be used for (claw arms etc.). However, in actually building a robot I haven’t found a practical use where a servo would work better than a regular 393 motor. We have a lot of servos laying around and I was wondering if I could find a use for them. My question is this: Have any of you guys used a servo on a VRC competition robot,
and where and why? Motors seem to do everything I need done on my VRC robot, so why are servos a thing?

Years ago, I used a servo to shift a 2-speed transmission.

Well a more fair comparison would be a servo to an old 3 wire motor. Which has identical torque and speed.

You would choose a servo if you only ever wanted 180 degrees of rotation and wanted good control on it. Anything to activate a mechanism, pull pin etc would be an easy example

Servos are great for accurate positioning with automatic hold. The Vex servos don’t have a lot of torque, but they work well for precise gripper mechanisms. None of our games have needed that directly, but it doesn’t mean they won’t. Shifting transmissions is a good use of a servo, and they’re particularly useful when you have to shift precisely to more than the two positions @Rick TYler mentioned. We’ve used a servo to slide the driven wheel across a friction drive plate. (Here’s a famous example: In our robotics application, the parts were much smaller. The servo lets you hit the same position accurately, so you get accurate “gear” ratios.

Depending on the direction of the forces involved, a gripper may not need a lot of strength in the direction the motor/servo applies it. Maybe the direction is perpendicular to that. Imagine, for example, having a spatula you want to swing sideways under something, while the vertical is supported by structure (and a lift other than the swinging bit). Now you get to choose if you use a heavier motor in addition to sensors to make sure it rotates to the right position or using a single, lighter servo and not using up sensor space.