THC raises to top of z axis when I hit start

Machine cuts great with THC disabled and touch set manually. When I set the machine up to cut with THC enabled the machine starts and the z axis raises the torch completely to the max height of the z axis and faults out. It does this Everytime. I ran the THC test multiple times and it passed everytime. Thanks

Welcome to the forums

What make of plasma torch do you have?

How did you hook up your THC? Raw or Divided ?

Where are you clamping your ground Clamp? on the material being cut?

We did the set up with the razor weld cut 45 and set it up divided. This is on the pro and we tried the ground clamp on the material and on the slats to trouble shot. Thanks!

Does it happen immediately once you start the program or does it happen after the torch has fired?

What program are you developing your CAM in and what is your retract height you set to?

It happens immediately when I hit start. We’re using fusion 360. When I get to the shop I’ll look at retract height settings. Thanks for the help!

Can you move it up manually with the page up page down keys without any issue? Lower your feed rate first to 50 or 100 ipm

Sure can. No issues there. I’m really starting to think it’s the retract setting.

The fact that it rises immediately when you hit start is making me think

“why it would have any call for an up movement at this time”.

Can you check to make sure your plug from the motor is fully seated on the electronics enclosure. Sometimes the screws that are meant to hold it in place can actually hold it out too far.

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keep it always on the material…on the slats can cause arcing between slats and metal throwing off the THC…
Are you on a plugged in laptop or PC…laptops should not be plugged in…

when you say it faults out…what error are you getting?

Interesting! Why should the laptop not be piugged in? I have been doing that and have also had some issues with THC. Works ok for the most part. From time to time it will suddenly raise up and flame out.

there can be grounding issues between the table / plasma cutter and laptop…

you either run the laptop not plugged in or use one of these

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Ok Thanks I will try that. I wonder if a rod driven into the ground would help. Ive heard that is sometimes required.

If it happens before the torch fires, the THC is not involved. The THC can only act on the Z Axis when it is receiving voltage from the plasma cutter.

There must be an issue with your programming or the Z axis stepper motor driver. Can you post one of your .nc files here, so I can see if the problem is in the code?

Stopped at the shop tonight. Fired the machine up and now it works. Thanks for all the help! I do not know what caused the issue but its working now. Thanks!

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