I have an old Practical CNC table with a new TD Cutmaster 82. I'm using WinCNC and have no THC. (I just use a pendant for THC) When I start the cutpath, as soon as the torch starts, the Z drives down super fast into the metal, and I can't stop it, I can slow it down with the up button on the pendant, but it still wants to go down.
If I disconnect the machine torch and just plug in the hand torch, then start the cutpath... I can control the Z completely as normal up and down, but as soon as I hit the torch start button on the hand torch... it dives down again fast.
I "think" this happened to me a long time ago and somehow I must have fixed it, but I can't remember what I did... It could have been a dream though for all I know...
One thing I did change was I used to have a TD Cutmaster 151 but it went bad on me almost a year ago. I replaced it with the 82 and now I have this problem. I did wait almost a year to replace it though and my table sat, unused, for that length of time. The problem wasn't there when the 151 went bad.