[davidmadewood]

Hi,
I have been working on a 4x8 ez-router scorpion for some time now fixing some of the stupid stuff that was done by this company when built.

From factory they put all their vfds in the enclosure right next to all the stepper cables, and use a non shielded SO cable in the same cable-tray all the way to the spindle. All that to say, you can imagine this thing has some DEMONS and is erratic ha!

1 - One problem I see are the stepper cables coming into the enclosure are stripped really far back and the drain is run all the way to star, but that leaves about 1-3ft of exposed stepper wire going to the drives.

2 - I think im going to go for a chainflex 4/12 spindle cable from ingus. and use emc shield clamps at both ends. Do you think this would be a good option?

3 - Do you think i should move the vfd out of the enclosure?

4 - All of the control wires going to the drives seem to single unshielded runs, should i run ferrites on both ends of each wire and shrink wrap them on the cables? I imagine this could help...?

5 - The cables at the stepper motor end are just molex connectors, the drain is attatched and grounds out on the stepper, its this best practice? or should I be using a emc shield clamp on both ends of each stepper cable like the spindle?

Higher res photo of enclosure - https://ibb.co/8XXGzGT

Thanks everyone!



CNC INFO:

4x8
3kw HSD
3phase power coming in

[Al_The_Man]

The first thing thing you want to look at is equipotential bonding of the earth grounding system. search here for Siemens PDF on it.
If this is done effectively, then grounding both ends of any shielding can take place.,
As to the VFD location, I have used two VFD's in the same control cabinet on one system with no problems.
Ensure you have a star point ground where all shields and grounds are referenced to, including the service earth.

[davidmadewood]

Thanks Al, I have been reading the 2 Siemens pdfs you and MAC provided. Very helpful and crazy how many manufactures dont follow them...

One questions for equipotential bonding. because my gantry is technically floating on bearing blocks, would it be best practice to run a stranded ground through the cable track and bond it to the gantry and Z axis, and bring it back to star in the cabinet?

[Al_The_Man]

That is what is typically done in a case like that.

[Davidjamesi]

Got it, what about the shield on the spindle side? If i use am emc clamp or gland can that ground just go to the z axis plate or does it need to carry all the way back to star?

[Al_The_Man]

Ground it to the Z axis mounting should suffice.

[davidmadewood]

If i use a emc gland to the spindle making sure that it is conductive to the spindle body would I need to run a separate ground from spindle to z axis mounting?
I got this gland
https://www.digikey.com/en/products/...DYEAYQF0C%2BQA

[Al_The_Man]

A proper GND conductor is always better if possible.

[davidmadewood]

Are you referring to a shield emc clamp? like one form ICOTEK?

[Al_The_Man]

If this is not a HS spindle then as long as the spindle cables are twisted conductors and preferably also carry a GND conductor, some kind of shielding is also preferred, either the cable shield itself or ran in flex metallic conduit.
That has always been my practice.

[davidmadewood]

If this is not a HS spindle then as long as the spindle cables are twisted conductors and preferably also carry a GND conductor, some kind of shielding is also preferred, either the cable shield itself or ran in flex metallic conduit.
That has always been my practice.

It’s a 18k rpm hsd spindle. I’m cutting wood.

[CNCMAN172]

Do yourself a huge favor and get a shielded spindle cable or you will be chasing ghosts forever