THC is running too high at times

i happened to be watching the torch closely as the machine was cutting the other day.

the thc has seemed to be working well as well as the rest of the table, but i noticed that the torch was running pretty high off of the material the other day, not the usual 1/16"ish. closer to 3/16-1/4"

i stopped the program, and recut the same line and it did the same.

i moved the ground just to see if it would have an effect, but still the same on the same line.

i couldnt get i to reproduce on any other part of that particular cut file, but have seen it one other time on a different file.

any thoughts?

It could be from slag getting on the torch tip. That would make the Z zero on that loop higher by the thickness of whatever is stuck on the tip. The THC doesn’t know how high it is. All the THC knows is that the IHS told it that a certain height was the Z zero. Firecontrol then pierces and lowers to the cut height based on that Zero and it takes a voltage reading at that height and tries to maintain that voltage for the duration of that cut loop. If a piece of slag held the tip 1/8" above the metal during the IHS cycle, everything on that loop will be 1/8" higher than it should be.

ah, i’ll check. makes total sense