I have been doing a fair amount of scrapping CNC equipment, lately.

It works out great, typically just the ironplus copper wires pays me
back 2x what I pay for the machine, and then I am left with servo
motors, boards, hydraulic pumps, coolant pumps, etc to sell.

But, at the same time I feel that listing and saying things like "this
motor comes from an obsolete piece of CNC equipment that belonged to a
bankrupt company" does not let me get the highest value for the item.

Whiel I have no hope of being able to test boards, I do feel that I
could adequately test the motors.

So, what would constitute a good test of an AC servo motor like a red
cap Fanuc motor?

I see a few things.

1. Run it from a VFD and measure vibration
2. Somehow test the encoder.

Anything else?

I know that there are companies that buy those motors for $200 each,
refurbish and test them professionally (this involves change of
bearings, rebalancing etc) and sell for 2,000 each. I would like to be
able to do the same and can invest a few grand into scavenging proper
test setups.

Any comments?

i