Ok so I went a different route. Didn't add to my cnc router, but built an entirely new CNC machine for plasma. I don't see a lot of info so I'm trying to figure out the specific things I need for plasma. I understand most of what I need, but then there's the little things.

1. I'm using a Promo THC and I understand I wire that to my Pokeys57CNC and set the pin assignments in Mach 3 and Plugins. Does the Promo THC unit, with it's two wires going to my Hypertherm, actually fire the torch or do I do that in Mach 3 and a relay like anything else?
2. The floating head system I built uses a limit switch, I've just based my design off what I've seen and understand the mechanical aspect. That limit switch is above the floating head. Do I wire that limit switch to Z Home? Then I jog manually, once, with mach finding the actual distance from hitting limit switch to the floating head being completely down, so when the program tells it to find the top of the work piece, it can go down > hit the work piece > touch the limit switch > and move the Z axis up to the correct offset distance? And that offset is the number I put in Z Home?
3. Does all that sequence, finding the work top with floating head, happen in the CAM I'm using, namely SheetCam? Or is there a macro I need to install?

Thanks.

The torch is fired by relay / BOB

IIRC the floating head switch is wired as the PROBE input - it will probe downwards until the torch hits the metal and the switch trips, there needs to be  a switch-offset in the math to give correct pierce height

If you use a Sheetcam POST that has plasma and top of material sense written in then yes this can all be done in CAM

Ok thanks, about sheetcam.

Some of the other posts mention using Z Home. I guess if I look at sheet CAM post it should tell me, I guess. I have a sheetcam trial and haven't installed it yet.

Ok I read another post where you contributed. I'll set it up as Probe. Thanks.

I'm assuming that on the hypertherm 85 there are two wires that need to be shorted to start the torch?

If you have the CPC port on the Hypertherm then yes, two of those wires will fire the torch but there is likely an interlock to defeat as well IF you have a hand torch fitted instead of a machine torch - that you will have to work out

I "modified" my PM45 slightly so i can use hand trigger OR CPC port trigger but note this can be dangerous so i won't say how i did it.

Cool thanks. I bought the combo package with a machine torch.

I'm using a Proma THC 150 and instructions had me wire ARC to an input pin on the Pokeys57CNC, but what Mach 3 function is it supposed to trigger?

Also what function do I use to turn on the torch? I have it wired I just don't know the function, there is a THC ON is that it?

Hi,
I think THC is a motion controller function, Mach does not do it the controller does.

Craig

THC is a function of the THC Proma Controller, but that controller has an ARC output that supposed to go to the Pokeys motion control board, I just need to know what I label that input so it can work correctly.

Hi,
if I understand correctly the THC signal UP/DOWN comes from the Proma controller but the pulse stream neccessary
for the motor to drive up or down comes from the PoKeys board.

Craig