[shewejff]

We had failures in our PG188 gearbox a few years ago that was used to direct drive an "arm". We broke off just about all of the teeth in the first planetary set.

What we essentially learned is that the driver was putting the arm up or down and keeping on driving the motor to keep there. Thus, if we have arms now, we put limit switches at both ends. The code is then set up so that if a limit switch is hit, the driver can't keep driving the arm against the hard stop.