Floating head touch off

AXIS 2.7.14 and a cheap 5 axis BOB. Primeweld CUT60.
I bought the computer with LinuxCNC installed and don't know much about Linux. I'll eventually go to PlasmaC and MESA controller but I want to start off real basic and learn more before I get into automatic torch height control.

Thanks for clarifying.

If you are going to use sheetcam, the call to the touchoff routing need to be issued in the post processor in the onPenDown method.

The touchoff routine is just a Gcode subroutine in a different file that is called from the main gcode file. I recommend that you hand write a simple gcode file (just cut a straight line one to two inches long). Once you have that going, then edit the post processor so that it replicates the code you need to match with this handcoded file.

If you can find a couple of spare parallel port pins (or add a second BOB), you could add the THCAD to your setup using the encoder component. Then you could either use the thcad component to add that to your existing config or upgrade to plasmac to add torch height control.

Thanks Rod. I've attached the edited post processor that I'm using in sheertcam. It loads the touch off sub (as text under function OnInit) at the beginning of the g code file, then calls the sub under function OnPenDown.
I've also attached the g code file from sheetcam of a 2 inch circle, inside offset with a 1 inch perpendicular lead in.
In sheetcam I have set pierce height to .1", cut height to .06" and pierce delay to 1 second.
In the generated g code, pierce height and cut height are okay, but pierce delay is 0.0394, instead of 1. It's like the post processor is treating the pierce delay as a metric value. (I set the pierce delay in sheetcam to 25.4 sec and the value in the g code changed to 1.00). It seems to me it has to be somewhere in the post processor, but I'm at a loss trying to figure it out. I tried changing the scale value under OnPenDown but couldn't get it to work right.
I have the Mesa 7i96 and the THCAD-10 boards but I won't be setting these up with PlasmaC until I have a much better understanding of Linuxcnc. Not comfortable yet working in the hal & ini files.

In your PP line 96 is : this is time so doesn't require scaling. Try:

I have a vague recollection that Sheetcam works in metric internally. Just one more reason for the US laggards (one of two remaining countries) to join the rest of the world in using real dimensions AKA SI units (metric to the unwashed).

Phil, That fixed it. Many thanks!