Cnc plasma and duet boards

ziggymanpopo

I've been using the duet wi fi board for a few years. And in the next six mo. or so i plan on building a cnc plasma table. Ofcourse I would love to stick with a duet board for the hardware. Can you all maybe make suggestions on what path would be a good one. ..what board would be best. I'm interested in using hight control
Along with a fairly large table min 5 x6 ft.
Some of the questions I had was stepper size
W/or without separate controllers for the larger steppers ect. I'm kind of known for a bit of overkill so I don't mind spending a little extra to over build it. Also I'm assuming that a software package would also be needed. Instead of a slicer program. Please advise and thaks for the input.

droftarts

@ziggymanpopo You already asked about this... https://forum.duet3d.com/topic/36148/cnc-plasma

Other plasma cutter threads for you to read:
https://forum.duet3d.com/search?in=titlesposts&term=plasma&matchWords=all&by=&categories=&searchChildren=false&hasTags=&replies=&repliesFilter=atleast&timeFilter=newer&timeRange=&sortBy=timestamp&sortDirection=desc&showAs=topics

The main issue is EMI when the plasma cutter fires up. You need to do the wiring carefully, shielding and grounding wires etc.

Ian

ziggymanpopo

@droftarts
thanks

droftarts

@ziggymanpopo Sorry, that was my quick reply, it was a busy day! For more research material, have a look at offerings from https://xtremeplasma.com/, they seem to be nicely-built machines. Looks like they use this controller and software: https://myplasmcnc.com.pl/. Video of one of these being set up: https://www.youtube.com/watch?v=r-0nW_NVlTA

To answer some of your questions specifically, bearing in mind I've never built a Plasma table:

Can you all maybe make suggestions on what path would be a good one. ..what board would be best.
Along with a fairly large table min 5 x6 ft. Some of the questions I had was stepper size
W/or without separate controllers for the larger steppers ect.

These three kind of go together. I'd say reasonable size NEMA23 would be plenty; you won't be moving the cutter fast, and it's not too heavy. So it's largely the same as regular CNC machines. Your choices are:

Duet 3 MB6HC - can easily power any NEMA23. Will keep the wiring simple.
Duet 3 MB6XD with external motor drivers and stepper motors - wider choice of motors, eg big steppers, closed loop, servo motors etc. Complicates the wiring, more to go wrong.
Duet 3 Mini 5+ with Duet 3 M23CL CAN connected motors - closed loop motors, simple wiring.

With all the wiring, including endstops, you'll want shielded wires that are properly grounded. Stepper motors bodies should also be grounded. For general guidance, see https://docs.duet3d.com/en/User_manual/Connecting_hardware/Power_wiring#grounding

I'm interested in using hight control

That depends on what kind of plasma cutter you go for, as some don't need height control. Looking through the other posts for plasma cutter recommendations would be sensible, though I'm not sure I've seen anyone do it yet. I don't have any experience wiring these up, so don't know how this may be achieved without seeing the specification/data sheet on the controller.

Also I'm assuming that a software package would also be needed. Instead of a slicer program.

It's 2D, so pretty basic. You can generate the paths in Inkscape, even. Most other CAM software will do it, eg Fusion 360. I can't remember if it's mentioned in the other plasma threads.

Please come back with any other questions, and keep us up to date with your build progress!

Ian