Plasma firing but not engaging fast enough and losing arch

[Dropgate]

Good morning.

I am new to the board. I have limited plas experience. I have set up an eagle plas with running a hypertherm 1650, machine torch, with the proma thc the wires to direct voltage as this machine does not have an arch divider. I have a couple questions. First whether or not I have the thc on or off when I try to run a gcode the plas will fire and pierce but blows the hole and sits too long and looses arch. I have changed the pierce delay to 0 and it still does this. If I start the gcode then manually fire the torch it will make the cut bit when it needs to shut off for a new pierce it does the same as described above. Second where do I hook the arch ok wires from the Plas. Thank you for you time

[acourtjester]

Are you using Mach3 if so you hook the arc ok (THC OK) from the Proma to the BOB board see attached image of the input signals and the pin selection.
This is also where you hook the THC up/down signal from the proma.

[tcaudle]

MACH THC requires three signals: UP , DOWN and ARC OK (aka THCON in MACH inputs). If THC button in MACH is on then when the torch fires it WAITS unitl it gets an ARC OK back from the plasma.. Your vendor should be able to tell you how you can get that signal and give you a MACH profile that works You have to enable the THC On and assign it to the right port and pin. I think the Promo fakes that singal and just sends an ARC OK when the voltage is present so it doe snot sense cut current to confirm it is a VALID arc (actually cutting metal)