On Saturday, April 13, 2013 8:59:49 AM UTC-5, Ignoramus17560 wrote:
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

Short the power leads, and turn the motor.
If it turns with a "lump" then one of the magnets is demagnetized.
Smooth, but high torque resistance, is good.
Not likely if it was being ran in a machine up until the end.