Setting up a plasma cutter and looking for some help.

I use a slightly modified one of these:

www.veloxcnc.com/xz-za-series

I added a homing switch at the top of the travel and longer bearings (ebay specials) to the floating part. I also use a home made magnetic break away torch mount. These aren't cheap but I needed to replace the TM AVHC POS, at first I still used the smartmotor and the box then finished switching to LinuxCNC.

John

I am thinking about using ohmic sensing. As I understand it i should be able to just run a wire from the torch head and one from the ground and treat it like a limit switch right? With an added relay that only connects it during probing so as not to feed back to the electronics. Is this understanding correct and natively part of plasmac? Slow feed down till it contacts, back up a touch and then real slow feed till it touches again?

The Plasma Primer in the main LinuxCNC doc page (V2.8 and above) includes the wiring for the ohmic sensing. And yes before plasmac, most of us used a gcode subroutine to probe the way you describe.

No eBay APP ID and/or Cert ID defined in Kunena configurationOk. Got a 7I96 and a thcad 10 ordered. Also ordered and a stepper driver. I figure I can tie the plasma head to a aluminium plate and embed some magnets in the plate and the linear stage to make it break away friendly.

Quick question. I have an old 5v a/b pulse coder. I know the THCAD uses one of the encoder inputs but is it possible to say put the thcad on the index input and the pulse coder on the a and b inputs? No big deal if not but I thought now would be the time to ask.

Probably a better solution would be to use firmware that supports a MPG on the 7I96's
isolated inputs. This is available but does require running LinuxCNC master (2.9)