Crazy torch motion during manual cut with DTHC

[xring]

Just completed my DIY build, mostly everything works. I have an ohmic sensor on the HT65 with the floating switch as a backup, the most recent revision of the candcnc Bladerunner hardware and commandcnc. One problem that remains is during manual cuts with the DTHC on. The cut starts normally, but a few inches into the cut, the torch does a 90° turn and dives. It doesn't stop until I hit the estop. The torch continues to fire, and actually pierced a hole in the bottom of my water table! Cutting from gcode or manual cutting with the DTHC off works fine.
Any suggestions on a setting I have wrong, or a way to prevent this?
Thanks!
Bill

[BTA Plasma]

Well do you have ANY data cables crossing over the torch or work lead from the plasma? Is the work lead coiled up near the control box causing a huge magnetic interference? Also are you using the top selection on the hypertherm (Continuous pilot arc mode) or the second?

[xring]

Well do you have ANY data cables crossing over the torch or work lead from the plasma? Is the work lead coiled up near the control box causing a huge magnetic interference? Also are you using the top selection on the hypertherm (Continuous pilot arc mode) or the second?

No, the torch lead is routed through an overhead boom, all other cables are through cable track. The work lead is not near the control box. I made sure the HT is on the second setting for solid metal.
The first time it happened I was sure I had hit the wrong axis jog key, but then I started to see the pattern of torch dive at the same time the cut went 90°. But works fine when cutting with DTHC off or with the torch off for simulation.
Touchoff and operation of both torch switches (ohmic and floating) work fine when cutting from gcode.
Thanks!
Bill

[tcaudle]

So maybe I have this wrong. You are trying to jog an cut with the DTHC ON ? It all works fine with running code ?
You can't use the DTHC doing a jog cut because feedrates effects the voltage and will cause the torch to dive if it below the required feed rates for the material. A. MANUAL cut has to be with the DTHC in MANUAL and OFF.

If the DRO readouts follow the motion then is being told to do that . Perhaps a noisy keyboard . During a jog it does what the keyboard or the Pendant tells it to

Get direct help on the CandCNC Support Forum

[xring]

So maybe I have this wrong. You are trying to jog an cut with the DTHC ON ? It all works fine with running code ?
You can't use the DTHC doing a jog cut because feedrates effects the voltage and will cause the torch to dive if it below the required feed rates for the material. A. MANUAL cut has to be with the DTHC in MANUAL and OFF.

If the DRO readouts follow the motion then is being told to do that . Perhaps a noisy keyboard . During a jog it does what the keyboard or the Pendant tells it to

Get direct help on the CandCNC Support Forum

Thanks, that makes sense. I was following the procedure for manual cuts suggested in the arclight dynamics video. Doing a manual cut with dthc on made sense to me for something like cutting a 4x8 sheet in 2 for my 4x4 table. Over the 4' width the material would have a lot of wave in it.
May be something else though. I ran into similar problems tonight on a gcode cut, for the first time. Torch dives down like it can't get down to the programmed voltage, the torch touches and breaks away, and it turns ugly. The torch continues to fire even after I estop. Happened at the same place on 2 cuts, but in a different place (further along) on another. I'm stumped for the night.
Thanks again,
Bill