Plasma THC

Rather than wading through Toma's Byzantine hal file, Why dont you start with the existing tchud component as rodw suggested a number of posts before. Thcud doesn't require access to any low level signals so it is applicable to servo, software stepper and hardware stepper systems. If it has deficiencies, fixing them would benefit anyone using a external up/down type THC device.

Okay, I'll see what I can do with THCUD; I suppose I'll learn how to add in the utilities as I learn the program.

@Grotius: I used PNCCONF to build a 7i76e before converting it to the 7i96, since there's no direct support for the board yet.
I do have a cheap parallel board and a parallel port card, but the torch I'm using has a HF start; which completely screws up the Arduino/GRBL board I was using...

I was trying to keep my rig away from the table, because I'm not yet running a water tray (long story), but I suppose this will have to work for now.

@David,

Your HF start wil demolishing every piece of electronic chip in and around near your plasma machine environment within no time.
Please don't do this at all, you are risking your 7i96 board.

Try to get a pilot start plasma first.

Why did you buy the Mesa card?

The Mesa THCAD card is promoted as being OK in a HF start environment. If you mount it on the plasma machine, and the 7i96 further away, the output is a frequency so should be pretty immune to noise and then you can put your PC up to 100 metres further away via ethernet. Well anyway thats the theory. But yes, blowback torches are so much better for CNC.

Exactly what rodw said, the mesa 7i96 is marketed as being hardened against electrical noise, which is why I bought it, as well as the board suported dual axis endstops for calibrating my gantry. I would love to upgrade plasma cutters but that comes at the cost of $1K+; not to get too much into it, I started this project with someone else, I alone am finishing it. The plasma cutter was just what I had.

I will upgrade my torch ASAP, however as far as I can tell this setup should work for now. I've got my controller and plasma on two different circuits to mitigate back emf, I'm using shielded cables and am grounding my controller enclosure.

Find the Hypertherm tech note on grounding and follow it. basically, they say to ground everything back to a "star" ground on the table frame including separate ground wires from every motor back to that point. The material grounding lead from the plasma cutter should be connected to this point as well. Hang on, I found it.This will be much more important for your HF machine.

My neighbors getting a hypertherm 30xp, maybe I'll see if I can borrow it and buy a machine torch lol.

Thanks for the info, I'm definitely not going to cut corners protecting my electronics.

I'm wiring up the THCUD components and I'm not quite sure how to handle some of the lines; motion-vel or how to write in the offset. Could I please have an example?

David,

Keep on following this topic : forum.linuxcnc.org/plasma-laser/34916-us...asma-thread?start=60

David,

You can connect your mesa if you want. Without connections, it also works.
The link is a special linuxcnc edition with a torch height controller. You can test this application and connect it easy
to your hardware.

read this carefully.