spindle interferes with steppers

[Doktor]

Howdo,

I have had similar issues with my Yakasawa VFD driving a small 3/4HP 3-ph motor. The issue was caused by the EM crud being emitted from the mains wiring out of the VFD. To cure the fault, I used a mains EM/RFI filter similar to ebay 161015962556 - mounted directly at the terminals of the VFD with only a couple of inches of mains wiring. The other thing that helped was the use of shielded 4 core cable up to the motor, with the shield being grounded at the VFD end only.

I hope that helps!

regards,

Paul.

What if stepper cables were 4core shielded?
Would that help?
Would You need to use shielded cable for spindle as well?