Building & setting up a rotary tube cutter

[razplaz]

Hello,

I have happily been using Sheetcam for a few years now on my gantry plasma table. Now I am currently getting around to setting up a rotary tube cutter using LinuxCNC to control it. The machine will be dedicated for cutting only 2" steel square tubing. I have the Sheetcam rotary plugin setup.

Couple of questions I have..

1. Will I need a torch height control integrated with this machine? I'm thinking not, but maybe someone will tell me otherwise.

2. Will I need a probe/touchoff routine in the Sheetcam LinuxCNC rotary post?

3. I currently have the machine set up as an XXYZA...with XX running on 2 rails along the length of tube, Y as the gantry, Z as torch height, A as rotary. I have seen where other guys are running different setups but am not sure for the reason, if someone has any insights about thisI would appreciate hearing them.

Thank you!

[bLouChip]

Welcome to the forum.

1. Will I need a torch height control integrated with this machine? I'm thinking not, but maybe someone will tell me otherwise.

If your machine will have a tube support/bearing which slides axial and is integrated with the torch mount or very near it, then likely no THC will be necessary since there should be zero tube flexing at the torch tip. Although there will be thermal expansion into the arc gap, you can account for that with cut height as it should be relatively constant for feedrate and amps.

2. Will I need a probe/touchoff routine in the Sheetcam LinuxCNC rotary post?

same answer as #1.

3. I currently have the machine set up as an XXYZA...

that should be fine. That will be the normal XA rotary motion. However, know that rectangular tubing does use YZ motion also when cutting shapes that encroach or span into corners.