lerker100:
Thanks for the info on the drivetrain. That is very useful information. Was that with standard or high-strength shafts?
John_TYler:
If the motor shaft is geared or chained to an arm or the like, there is still a direct relationship between motor shaft rotation and final manipulator rotation. It is just a matter of scaling.
Yes, but that’s not the type of thing I was talking about. There are robots that use idler wheels connected to no motors for the purpose of telemetry. To boot, just this year we had robots using slip gear catapults. The position of such a catapult is not always related to what the motor is doing. Motorless encoders aren’t without their uses.
4 motor 4 omni wheel base using Standard shafts
Fair point. The idler wheels for telemetry is a great example.
Would a potentiometer work for a catapult? That would have the advantage of being an absolute position reference (so you don’t have to worry about initializing it).
Pots did work on catapults (our Y team used one all season), although I personally found a limit switch to work better (doesn’t add any friction, and works with a HS fulcrum without an adapter).
EDIT: we actually used the integrated encoder for almost all of last season and as long as it started in the right place we had no problems with it. The only reason we switched to a limit switch is that I got tired of turning the slipgear by hand.