PMDX Forum

General Category => SmartBOB controllers and dedicated accessories => Topic started by: bwolfe on July 24, 2018, 11:43:37 PM

Title: Should I ground my motor to PMDX-133 Ground?
Post by: bwolfe on July 24, 2018, 11:43:37 PM

I have PMDX-133 mother boards,  Gecko G203V drivers, NEMA 34 stepper motors from CNC Router Parts and their shielded cable assemblies & bulkhead connectors.

Should I connect the ground wires from the bulkhead connectors to the ground pins on the PMDX-133 output connectors?

I’m asking because I’ve seen discussions here about ground loops if both ends of a shield are tied to ground.  I’m pretty sure the motor is grounded to the shield...

Title: Re: Should I ground my motor to PMDX-133 Ground?
Post by: bwolfe on July 25, 2018, 06:17:02 PM

I see people have read this.  Can someone comment?  Thank you.

Title: Re: Should I ground my motor to PMDX-133 Ground?
Post by: Steve Stallings on July 25, 2018, 07:16:24 PM

Ground loop issues usually matter for input signals, but not for things
like stepper motors or spindles. Noise radiation from these cables
to other parts of the system can matter, especially for spindles
driven from a VFD.

Noise issues are funny, and there is no one right answer. If you are
not having issues with the stepper wiring causing false signals on
one of your inputs, and if you do have a safety ground to the metal
parts of the machine where the motors are mounted, the I would
tend to not connect the ground from the stepper motor cable.

Title: Re: Should I ground my motor to PMDX-133 Ground?
Post by: bwolfe on July 26, 2018, 08:51:14 AM

Thank you Steve.