4' x 4' x 8" Router Build

[JonnyFive]

Yea and do the same with the control/comms wire to/from the vfd, except connect that earth to your main star ground in/at the cabinet end.

No ground loops etc...

You mean the wires going to DCM / FOR / ACM / VI on the VFD?

[Lee Roberts]

You mean the wires going to DCM / FOR / ACM / VI on the VFD?

No, sorry I meant to say shielding not earth, but yes the shielding for that group of wires, not the connections themselves...

So I'm talking about the control wire you would also install so that the main cnc controller can control your VFD from software.

Also, I think you should choose Doddy's advice and mine on this one and definitely connect Pin 4, it costs nothing to do and I too would rather sleep well at night knowing your/my spindle housing is properly wired to be safe in a fault condition.

Earth/ground is there for safty first and should be used as intended, using it for noise drain should be considered as a secondary bonus feature in this application in my opinion.

Noise issues can be isolated and remedied, restarting your heart isn't as easy to do...