how to makeTHCAD10 work with pilot arc plasma

Hi everyone, i hope you all went safely through this shitty virus.

I'm currently struggling with my THCAD.
I dont have any variation in voltage according to cut height.

So i think i'm on to something, i'm using a shitty Chinese plasma (waiting for €€€ for a Hypertherm) with HF start.
And the way it works, as i understand it, the arc is generated between the cup shield and the tip, but the shield is ALWAYS connected to ground. So there is no variation according to distance between the plate i'm cutting and the tip.

I would like to cut the connection between the shield and the machine when the ARC OK signal is green (ON)
But i'm at lost here, i need to declare my IO pin to drive a relay in HAL, that i can do i think, but how do i make it interact with the ARC OK bit ?

yes it's connected to ground clamp inside the machine, it's a pilot arc hf system, i should say the nozzle not the shield in ceramic.
The only way to have a variation in voltage depending on distance from plate to nozzle is to cut this wire when arc ok signal is calculated from THCAD input voltage

it's a Panasonic 80 head, very basic and cheap chinese

nope that's an even older type,


They guy in your youtube video is modding a regular torch to pilot arc by adding the grond wire to the nozzle, like mine already has.

yeah i know it's weird, but i only need a way to have the ARC OK bit activating an output to open a relay so it can be disconnected from ground.
As in your video you can see the plasma working even though the ground is connected on the nozzle to make it a pilot arc.

Or i can add a relay activated by the TORCH ON signal with a delay of 1 second.

LOL yes, i did think about it, the wire they use for the pilot arc ground is 1.5mm² i guess it does not have that much amps going through, and with this solution i might be able to keep the nozzle longer as the arc will be on the plate and not on the nozzle.

I'll give it a try today and report back