Setting up a plasma cutter and looking for some help.

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.

Ok. Got a 7I96 and a thcad 10 ordered. Also ordered www.ebay.com/itm/254256957860 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)

Ok. Thanks.

That just went from low priority to no priority. Can't get the motors to move at all with the mesa card when trying to set them up. Trying to figure out where I messed up. All the wiring looks right. (Only have x and y hooked up. All my z stuff arrives monday and limits can be done later.) May hook an oscope up and see if it is utputing the signals or not after lunch as it should work as far as i can tell.

Edit: I am on 2.9

Most common reason for no motion (assuming wiring is right) is too short step length
Start with 5000 ns

Is where it was when I left friday.

I have seen mention of firmware for the mesa board. Am I supposed to change it from what it comes with out of the box?
Is there any sort of enable I need to wire on the mesa board?

EDIT: 154 shows the step timing. www.teknic.com/files/downloads/ac_clearpath-mc-sd_manual.pdf (Should not need a log in as while they block the links behind a login direct links should still work. Let me know if different and I'll rehost.)

1. The supplied firmware should be fine unless you are using an additional
THCAD for ohmic sensing

2. The Teknics drives require that their enable input be asserted before
they will operate

The drives are enabled. (I don't actually have the drives I linked. But the manual for the SC ones does not list the full step timings so I linked the other manual.)

www.teknic.com/files/downloads/ac_clearpath-sc_manual.pdf is my actual drives. They are enabled/disabled with a software command. At some point I need to figure out the actual code for that so I don't keep dragging my laptop out there to enable them but thats a later issue.

If I hook to the paraport breakout board it was working just fine.

I will mess with it more monday. I ended up leaving work an hour early friday as I was annoyed and did not see another hour helping my mental fugue at the time.

So got back in here with a clearer head. Hooked an oscilloscope up to it and am just seeing a straight 4.65V output signal out of the mesa board rather than any pulse/dir signals. I am hooked to step0+, Dir0+ and both of the other wires to gnd (Same for step1/dir1 as well)

I can ping the board via the terminal but don't see a way to tell if pconf sees it. I know t does not give an error if I give it a bad ip.