Rotary Plasma using just X Y Z

I’d like to try and drive my DIY plasma tube cutter using Sheetcam + rotary plugin. If cutting tube, everything is performed using X (tube feed) Z (torch height) and A (tube rotate). My machine is a 3 axis with Y being rotate.

Two questions

  • When using round tube, sheetcam generates a toolpath using X, Z and A. Can the A axis be mapped onto Y - or will I have to do that in my controller?


  • If using square tube, sheetcam uses the Y axis to move the torch back and forth. This is not possible on my machine as only 3 axis, but I’m hoping it should still be possible to make the cut, obviously as the tube nears a corner the torch will not be square to the surface - but never more than 45 degrees. The torch clearance may need to be more to accom but maybe this would still work on thin wall tube… Is this possible to do in sheetcam?

Yes the A axis can be mapped to Y in the post.

You need 4 axes for square. As you say it is theoretically possible to cut square with 3 axis but when you get near the corner the edge of the nozzle is likely to hit the work. If you lift it high enough to clear you end up with a very long arc length which, combined with the angle of the work relative to the jet, is going to result in an ugly cut and poor consumable life. If you have THC this also guarantees that the torch will crash into the work.

Thanks Les,

That makes sense - guess I’ll need to work in a true Y axis for the torch!