Question: I need to operate a servo motor in a vacuum, what are some considerations?
Answer: In a word? Outgassing. You might think that proper motor sizing is a big issue, it always is, however if you can't conform to the other process requirements, there is no point to attempting to size the motor. The biggest issue for any given motor selection to be run in a given vacuum for a specific process is the outgassing requirement, or rather, the avoidance of materials that would affect the process being performed and/or the life of the motor.