Hi,

I hope I am OK asking this as I don't think its a Mach3 issue more (I think) a earth/emi issue but could really use some help.  I purchased a Chinese 3020 and after a VERY steep learning curve I am now confident in creating and then cutting what I need.

i have added limit/homing switches, touch probe and managed to set up the xyz zero touch macro, also I replaced the (i think 24V)  200w spindle awhile ago to a 500W, 0 to 100 V spindle with a separate power supply and separate potentiometer.


I think the issue started after changing my PC (the old one died) when i manual move xy,z with the arrow keys the steppers move the spindle around fine unless the spindle is spinning, soon as its spinning and the arrow key is held down, a stepper moves a bit, pauses (no dro change) and then most of the time with the key still held down starts moving again.

I unhooked the spindle from the machine, and plugged it in at the other end of the room on a long extension cord, if its spinning more than about 2 meters away from the CNC machine, all is good but when I move it closer the pausing starts.

Is this a electric magnetic interference (EMI) issue?  the spindle power supply only has connections for live and neutral and I have connected the wall socket earth to the power supply chassis. Only 2 wires go from the power supply to the spindle.

I tried touching a metal part of the spindle and the spindle power supply with a long wire connected to the cnc controllers ground connection but no improvement, any other suggestions would be appreciated and sorry if I have put this question in the wrong section.

Thanks

Shaun