The Dreaded X axis stepper error using UC400ETH and UCCNC !!!

[dachopper]

Ok First from what you have said are you sure that you have a good earth into your shop (is it actually connected)?

Where are the pictures?

It is beneficial to wire steppers with 4 core screened cable with the control box end of the screen connected to the star point.

Personally I would keep the vfd mains wiring on its own socket.
If you have grounded the screen on the spindle cable at the vfd end. then don't connect the screen at the other end.

Have you grounded the machine frame? to the star point. (the purpose of the star point is to avoid ground loops)

I take it that the electricity supplier give you an earth connection and that you are not using an earth rod in the ground.

Hi clive....

So this is what I'm at now.

I checked all the stepper motor shielded cables, made sure they were insulated at the stepper motor end and touching nothing, then at the control box end they all go to the star point.

The VFD spindle/Z axis block is now earthed direct to the star point. ( No other frame earth, just the one on the Z block )

The VFD cable shield is earthed separately onto the same star block, and it's insulated at spindle end ( not touching the spindle )

The other AC appliances ( VFD + Wood chip motor + 2 x pumps ) are all earthed at the same star point where applicable.

On the earth side - I'm using the house common earth..... how can I test if this is faulty?


I was a little concerned about the cable shielding pushing an AC signal back into the stepper motor shielding, but it seems to be going ok, 40 minutes into a cut now