well, not techincally a THC.. but it seems to be working well for piercing.
i already had the torch mounted on a slide (Z), but no Z drive/stepper.
i installed a small air piston with a needle valve. i can set the needle valve to lower the piston/torch when the torchON signal goes live.
the torch lights high, then as pressure builds the piston brings the torch down to the work. air off and the piston snaps it back up.
tried it with and without the piston and piercing seems cleaner (oddly, more so in medium sheet than thin or thick stock).
Les of Sheetcam says he's working on ramping routines for the torch, hopefully i can get it to move a bit on the lead-ins while the piston slowly comes down.
i'll post pictures if anyone is interested.
though i forsee myself shortly moving to BobCampbell's THC unit.
Very interesting... yes, please post pics... the more the merrier Videos tooooo