Consensus here seems to be wiring I think. I will check the USB/PSU Jumper,
I replaced KK with CP1-10 provide spindle control , but the latter packed in so went back to KK (may have overlooked the jumper at that stage.)

I think it is maybe worth a rewire anyway. I used 0.5 throughout and while I guess it is probably OK for the signal wiring I did wonder whether to beef it for the motor wiring ( PSU seems to be giving steady +42 V as far as you can tell on a digital Multimeter)
I dont think the couplings are the problem It seems to happen randomly on all axes

Looking at the table arrangement what settings would you guys choose for the driver currents?


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I will go back over wiring and grounding of shielding, I will also put a seperate 5v to the board and then Come back .
If it is with good news then fine , If it is not good then maybe I should start a new thread as I think Doddy suggested .