Well, Spoke to soon! Although the motor tuning appears to be better and it certainly still sounds better. I have had the same problem come back. The stalling and the engraving being out of line by about 10mm as though the motor stalled again (complete with grinding noise!)

I turned the power off and swapped over the X and Y axis connectors at the 'blue' controller breakout box. Looking to see if the fault would swap over the the X axis (My fault has always shown on the Y axis so far)

Lo and behold I rotate my workpiece by 90 degrees and power up and run the machine again. The error appears again exactly the same (but without any really noticeable grinding on the machines X axis. Apart from the engraved text appearing backwards the error is in the same place on the workpiece. This I think tells me that the problem is in my Y axis driver board? Plus my Z axis (at approx the same time as the initial Y axis error reappeared seemed to plunge deeper by about 2mm after/ same time as the Y axis stalled. Inside the breakout box the driver boards are separate.

Am I right in thinking that it can only be a crappy control box (mixed with maybe crappy unscreened -and not star earthed either..)

I'm now looking at replacing the existing chinese cable in the 6040 router with screened cable is this the best thing to do and any links to the best 4 core stuff to buy for the job please?

Also I am going to need to replace the break out box. What is the best and easiest stepper controller solution in the UK. Balancing cost and quality. I would stick with the stepper motors I have for now but probably need to upgrade this crappy control box.

Would really like to hear your suggestions guys.. :-)

Thanks again Andy