OK, make sure that the rotary switch is in the "0" position.
Set the current to 3.6A and then power up.
Then move SW4 on and off twice to get the driver to tune to the motor specs.
Once this is done it should work ok.
Make sure the signal cables are not close to any power cables.
When you power the driers up, did the inverter for the spindle power up? if so disconnect it.



Quote Originally Posted by Shinobiwan View Post
Thanks for the help.

The stepper cables are shielded and ground at the control box end.

I'll try changing the current to what you suggest. The motors still made the same noise with the default setting of 1A before I changed it to 3.93A so no damage done to the motors.

Will play around some more this afternoon based on whst you've suggested.