Re: RF interfering with stepper motors
You have not really given us much to go on. What is your CNC controller? USB, Ethernet, Parport? What voltages are you using for your home switches etc?
What THC?
Are you using shielded stepper cables?
Is the cable shield unconnected at the plasma end?
Has the shield been passed through any connectors on your control box and grounded as close to the stepper controller as possible?
Have you followed the Hypertherm tech document on table grounding?
Have you got a centralised star ground on your table?
Do you have seperate grounding cables from the case of every stepper back to the star ground?
How long are your 5 volt signal cables to your stepper drives?
Do they run along any mains cables?
Also consider fitting a mains EMI filter to your control box. That and properly grounding my table were the biggest wins I had.
From the list above, you can see there are a lot of things you can do to improve interference from noise and I only know about these things because I had problems on my system.
Rod Webster
www.vehiclemods.net.au