On my 1984 Faxac mill with Heidenhain controller and Infranor DC servo amplifiers theres a big inductors in series with the brushed DC motors.
They make a terrible squiling noise when I run the machine, I have tried to bypass them but then the motors run warmer and the sound generates from the motors instead (altough alot lower)
How can I make the machine silent?
Why is the inductor needed?
What value should new inductors have?
The drives are X: 15A\165V Y: 15A\165V Z: 30A\165V
Greatfull for help