Linuxcnc plasma rotary

Are you using the THC to follow the contour of square tubing or from gcode output of sheetcam driving Z axis without THC?
Did some experimenting a while back with a fast Z axis and a Prima THC, it did work quite good, but noticed that on the way down the torch would lag a bit meaning to high from the tube, but the cut was OK. This was with max. 50X50mm square tubing, did not need more so did not try but I doubt it would work as the slope becomes to much for the THC to follow. Also this was with only one moving axis, so the torch was moving only in one axis and Z height.
I am aware that having both axis X and Y moving and using a post processor is much better and can cut any size the machine can handle, but I did not have the post processor and lacked time.
Thanks for the info.
BTW, the last rotary I built had only probing with no THC as it was only for round tubing. Ended up pretty cheap and the client is extremely happy with it. Also looked nicer than the rest of my machines. I did post pictures and videos here I think.......or did I???

@Tommy,

Are you using the THC to follow the contour of square tubing or from gcode output of sheetcam driving Z axis without THC?
In my case we can do both option's. It will execute the movement's based on gcode. When activating the torch height control
it will do correction's based on torch volt control. The torch volt control is based on the integrated Exernal Offset branche.

Did some experimenting a while back with a fast Z axis and a Proma THC, it did work quite good, but noticed that on the way down the torch would lag a bit meaning to high from the tube,
Users can use the Probe function if they want to. Optimizing the switch offset value output's in a perfect start height. But i prefer to not use the probe function for tube cutters.

I did post pictures and videos here I think.......or did I???
Yes, you did post pictures of your tube cutter application.

Additional info for tube cutters in linux.

The negative adaptive feed result's in a very simple restart procedure, done by the component. In my case the THC2 component designed for sheet metal cutters works even so good for a tube cutter i mentioned.

Thank you for letting me know, I was not sure if I did post it. Way to much to do and another issue I have since the end of last year is I will have to move soon as my house and workshop are going to be demolished to make way for new buildings so I can not expand the workshop for now and it got very cramped there so a lot of projects got frozen.
Not a nice feeling at all, but the good thing is I will have a much larger workshop, but the wait is killing me !!!

Hi Grotius,

Many thank´s for sharing your work. I was testing your post doing a P (see attach) and i got it mirrored.
I used the rigth hand rule (see attach) to configurate the rotary axis pointing thumb to the chuck.
Since is my 1st time doing this application what i am missing here? Machine setup, Sheetcam setup?
Thank´s in advance.

Your geometry might be assuming that the shape is below the centreline.
I think that the rotation radius maybe should be negative (bigger radius = smaller Z height)
I have a similar problem with my manual-B 5 axis setup.

Hi Andy

Glad to talk with a master.
About center point, in the machine i am setting 0 @ center chuck.
In sheetcam i need to put positive otherwise it set wrong the working space.

Thank´s in advance.