Problem with THC

Hi,
I have a machine that has a Hypertherm 105 Sync source on and I am having issues getting the THC to work correctly.
I had to adjust the THC_delay to 5 seconds before I could get a stable voltage reading for Autovolts. The torch will go down to the cut height but starts moving upwards before the THC_delay has timed out. The cut voltage seems to settle at 55V but the torch moves up until it reaches 75V and stays there.
The strange thing is it will cut the first cut correct and then misbehaves after that.
Any ideas where to fiddle?

Use halscope to do a plot of encoder.0.velocity pin during a pierce, might be interference, although as you are getting 55 and 75V readings it also seems not right, and this might be due to scaling and/or due to interference.
What divider ratio is Mesa THCAD set to? Usually 1/32.
If this is a new machine, disable auto volts, disable void lock and velocity lock, well disable everything automated until you get the machine working correctly, only then enable the automation.

It is a new machine. The divider is set to 1/32. I am not sure what voltage is given by the source as this is also a new configuration Hypertherm that does stuff automatically. It reads the consumable and does it's own adjustments. Although I disabled that feature on the plasma source. It might still be doing something that I am not aware off.
The voltage seems very stable . The thing that bothers me is that the torch starts moving up as soon as it starts cutting. It does not delay the 5 seconds that I set the THC_delay to.

You need to plot the voltage or encoder with halscope. I think that is way too low. I would expect around 130 volts. I suspect the THCAD is not properly calibrated. The plot will tell you how long to delay. I would check the input voltage at the thcad with a multimeter.

I did have a machine once that needed about 2 seconds to be stable...

I use this calculator to calculate the parameters for the THC.

jscalc.io/source/ScVgoteuXJ9ySlXo

Can you check to see if it is accurate please?

How do others determine the volt/mm if you don't use Autovolt?