If you metered with the black wire to a ground terminal ( AC outlet) and red wire to the + on the torch( clamp) what do you get when torch is idle? Does this clamp voltage change when the torch is cutting?
I’'m thinking of concepts to rig up a zero-springback intial torch height switch as an option to built in z axis switch which can way off if the material is flexing. The concept in mind is to let the torch make contact with the material, and a circuit triggers the software instantly upon contact versus having to press the material and after several pounds of force( torch weight etc) before releasing the switch. I’m wondering if instant switching would be an advantage.
I don’t have a cutter at the moment to check myself.