I have an 5' x 10' cnc plasma made by http://www.ldrmotionsystems.com/ with torch height control and a hypertherm 45 plasma. I do not have the table grounded. The issue is when trying to set the home the gantry will touch the home switch and not back off the machine. If I try to cut the machine does not stay on path and can be eratic. This has started again, I have been cutting for the last 6-7 months with no issue. It seems it could be weather related since the weather is warmer here in Vancouver BC now and i havent had this issue since late summer last year. When I move the gantry the motors will have a different sound when it is not homing properly. If I leave the machine off for a few hours it seems to home and work properly for a short time. Could this be a grounding issue?

Thank you in advance.

Marko

From what you describe the problem is more likely to be a temperature issue rather than grounding.

Check that you have adequate ventilation / cooling at both your PC and your motor controller. Are your motors perhaps getting too hot ?

Tweakie.

Proper grounding of a plasma table is important both for your safety and for your electronic's well being.

Perhaps post #9 in this thread by Jim Colt of Hypertherm will help.

The building is cool and the motors do not get hot. The machine will have this issue when it has been off for days as well, I am going to install a ground rod today to see if this will fix the issue since it should be done this way anyways and report back.

Thank you.