THC Problem - Linux/THCAD10/SheetCam

-Use shielded cables for everything
-Keep cables as short as possible
-Avoid signal cables going in parallel with high power cables
-Connect the cable shielding ONLY on the controller side to ground
-Make sure there is proper grounding all the way to the control box
-Do not daisy chain grounding cables, star connections only from a single point in the control box
-Do not connect all the "-" and GND wires together
-Use separate isolated power supply for 5V to the Mesa logic side and another one for the output side
-Keep the torch and ground clamp cables as far from the controls/signal cables/PC as possible
-Avoid using new cheap keyboard and mouse, find used Dell or HP or IBM peripherals. New are not shielded

Also go through this if you feel like it:
forum.linuxcnc.org/plasma-laser/35349-cn...fo-and-guide?start=0
forum.linuxcnc.org/plasma-laser/38974-di...rything-in-one-place