Plasma - Big Problems - HF Start !!!

[irving2008]

thanks for the reply
the machine works fine no issues until I start the plasma torch and the HF sends the stepper motors shooting off !

regards

Jamie

Are you saying the motors spin on their own? then you have interference in the step/dir lines to the drivers. Where are the drivers in relation to the torch? You need the shortest possble cable between PC and drivers. The interference could be getting into the motor wires and thence back into the controller. Is the plasma torch on the same mains as the power supply to the drivers? You might need an RF Filter (like you'd use on a VFD) on the input to the driver PSU, AND on the input to the torch PSU.

If you disconnect the breakout -> drivers cable and start the torch do the steppers move? if not, reconnect and remove the cable from the parallel port. Does it move now?, if not, do they move with the PC on but MACH3 not running.

Need to try and isolate where the interference is getting in the system. You may need to put the motor wires through a ferrite ring to stop HF flowing back up there... and all cables should be shielded, when that plasma starts its like a mini-EMP!