[Type75]

I am thinking about making a homemade CNC Plasma Cutter. I was thinking about making a 4x8 table because that is stock size sheet metal. Because I am trying to keep price low, I was not planning on buying a gantry kit. Would it work well and be accurate to use roller chain to run the X and Y axis and a threaded rod to move on the Z? The plasma cutter I would use it with would be a Miller Spectrum 2050. What would be the best way to fire the torch?

[Torchhead]

How you gonna move this contraption? The torch fire signal needs to come from the control software typically using an output and relay....course you can go really low tech and just find the two wires that fire your torch in the handle and wire in a push button and just do it manually . Not sure if they call that CNC or just an automated pantograph

[Type75]

I was planning on moving it with Nema 23s and have it roll on V bearings. Do you know if there is anyway to fire the torch without messing with the wires?

[jim_r53]

If you haven't already seen it you should check out the build thread by MountainCrafts http://www.cnczone.com/forums/cnc-wo...ld-thread.html

[Type75]

I was hoping I didnt need to buy a different plasma cutter. Would V bearings and chain be accurate or should I try something else?

[crasher455]

Miller sells a machine style torch for that machine, Torch, ICE-55CM that gives you an extra output connector for using an external trigger switch. However it is very expensive. If you want to us the hand torch I would say just open the case and splice into the two trigger wires. According to the Miller schematic for that machine it is terminals RCI-3 and RCI-4 here is a link to the schematic http://www.millerwelds.com/om/o2228r_mil.pdf.

As for using roller chain to drive the machine axis, It will work. But your edge finish will suffer from the movement not being smooth. The smaller the chain you use the better. The inconsistencies will be noticed the most when cutting arcs. On a 4 x 8 ft table you could buy gear rack for around $300.00 or less. Are you planning on using this for hobby use or business?

[Type75]

I was planning on using this for the most part hobby. Once in awhile sell some stuff with it. After looking at it more im going to wait a couple years when I can build a more quality one.