I have noticed when cutting letters, they seem to get out of line.
the two half’s off the letter O, the right side will cut higher than the left side and it seems to continue this as it goes.
I have squared up the gantry, it was a little out of square and it seemed to help. What else could it be?
Does this machine use stepper motors? It sounds like your motors are losing position. Try reducing the acceleration or maximum speed. You will probably need to experiment a bit to find settings that are reliable.
Yes it does have stepper motors. I have also noticed as soon as the torch fires, it jumps, only in the Y axis. After studying the moves I believe this could be a HF issue also. Only does it on the Y axis, X and Z are not bothered by it. Maybe more grounding. Any thoughts?
Thta does sound like a noise issue and is quite likely the cause of your problem. Good earthing is important with plasmas. Make sure all of your grounds meet at one point and only one point. The easiest way to do this is to attach a bolt to your table somewhere convenient. All grounds need to meet at that bolt. If you use screened cable the cable screens should only be grounded at the computer end. They should be insulated at the other end.
Thanks Les, I will rework the grounding and see how it works then.
OK, so Ive run all my control wiring in a copper woven loom. It is a lot better but still have some RF interference. My PC is not in an enclosed cabinet. Should it be? and if so should it be steel or is aluminium OK? should I build an enclosure for the Plasma machine it self?
Thanks in advance for the help. This site is awesome!!!
You should not have to resort to mounting the computer in a box. However if you do it shouldn’t matter if you use steel or ali.
I have had a fair amount of success using ferrite toroids. Put them on your motor cables and input/output cables. This thread on CNCZone http://www.cnczone.com/forums/general-cnc-machine-related-electronics/17222-ferrite-donuts-toroids-suppress-noise.html explains how they work.