Unless you programmed it with different operations for the inside and outside cuts, there is nothing in Sheetcam that will tell the torch to rise like that. If you created different operations for inside and outside and used a different tool for each, then its possible that your cut height is wrong in one of the tools.
Otherwise, this is a problem that is occurring between the control box and Firecontrol. I’ve never heard of it before, but Cameron from Langmuir commented on a similar Facebook post about the IHS wires being loose. He said that loose wires could cause the IHS system to report that the switch is open and the torch will rise .060" each time it happens, because the system thinks the torch is touching the metal. Watch the screen during the cut and see if the IHS light goes on and off when it rises.
Just a thought but depends if the inside cut are short enough, it would not give the THC to rise badly during that cut. but during the outside cut which is longer this gives it enough time to react poorly to the incorrect height.
Good point I had that issue early on where the ring connector from the IHS would become loose where it was screwed down on the Z axis.
This is something that was new to me, but it makes sense. Apparently, if it happens during the cut, it doesn’t throw an error but raises the torch to prevent a collision. If it happens during the probing sequence, it throws an error and stops the program.
I just had my THC not work for some reason. When it was cutting, it just decided not to lower on a section of plate that was slightly lower and did not cut all the way through and had no codes. Have you seen this happen before?
Sounds like your z-axis might be binding up. Without cutting just use the page up and page down keys on your keyboard to raise and lower the z axis at about 50- 100 inches per minute see if there’s any sticking or binding happening you may have to make some adjustments to the travel.
Is it possible that the Z axis couldn’t go any lower because it was already as low as it could go without triggering the IHS switch? If it lowers enough to trigger the switch, Firecontrol will raise the torch by .060" as a safety measure.