Last year we used worm gears to power our shoulder mechanism for the first part of the UTC regional. We removed the arm primarily because it unbalanced the robot.
We adapted the FP motors to go into the Bosch transmissions. On the output of the transmission we had a six point socket attached. The socket interfaced with a bolt that the worm was welded to. The worm assembly was setup with 4 bearings, 2 flange type radial and 2 thrust. The worm wheels were soid mounted to our shoulder shaft and the motors and transmissions were mounted to the arm. It worked well for moving the arm and locking it in place with no back drive, but alas few ever saw it work properly for many reasons.
Pete