THC mid air acrobatics with THC on or off

I’ve got an interesting development with my THC cutting .080 Alum. I cut out several large parts yesterday with no issues. Today on the same piece of alum .080 i went to cut 4 small rectangle parts with the same settings as before and it started the cut, went on around the first corner down one 7" run, around the 2nd corner and 3/4" down a 1" run to the next corner the head picked up and lost arc. The work clamp is on the part about 12" from the cutting area. Wiggled it around and restarted the cut and now the torch in mid air acts as if it hits the work piece and fires in mid air then starts to run. If i set the head right on the work piece start the program it picks the head up in mid air and drops down like it hits the work piece and does the same thing. I pulled the head apart, checked all the consumables, there still in new condition. I tried changing some settings in the THC control for larger sample size and lower tolerance but they had no effect. I turned off THC and put the head down on the work piece and the dang thing picked up like under THC control and fired above the piece like before and that has me scratching my head. Why is it trying to control the height with it turned off?

Settings are cut height .06, pierce .6, pierce height .1, pierce 40A, cut 35A

THC health check 135.4v

Your z axis is dirty or binding that or something going on with the ihs switch. Make sure no debris is around the switch. Also check wires going to the ihs.

It’s not the THC that controls the z on the start of a cut it is a ihs issue.

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I reloaded the program and instead of generating 3 other parts to run in sequence i cut 3 of them one at a time and it worked fine. Strange.

Torch cable have enough slack to reach where it was trying to cut? That will cause it also

Aluminum is nasty to cut and blows glitter all over. It’s likely that you got aluminum particles on the Z axis rods and the Z carriage was hanging up on them, tripping the IHS switch.

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