Hello!

After building a laser engraver I'm thinking about a simple plasma tube notcher. The idea is to cut notches, specific holes and shapes out of stainless round tube.

But I've got a few questions.

when using a lathe chuck, how do you program the system that it knows the diameter? 1 inch is a big difference with a 3 inch tube. For 1 project one full turn is 150 mm and the next project it is (lets say) 300 mm. That is quite a difference in cutting speed. Simply lowering the cutting speed would not work because your cutting in 2 axis, also along the tube.

Why not use a rubbercoated wheel attached to a steppingmotor and rest the piece of tubing on that wheel. Then you automatically fix the diameter problem and you could simply make a 2d dfx drawing to send to mach3.

Example: Cutting a notch or shape on a 100 mm tube? simply draw a flat CAD drawing 314 mm (diameter*pi) high and that would be 1 full turn of the tube. Just scale the coping shape to the right hight and your done. Would it be that simple? This sound to me like a easy, understandable and easy to work with system.

I hope this is understandable, my English is not bad but the technical explanation is quite difficult. If not clear, I'll make a drawing.

What do you guys think?