[awerby]

What's the difference between micro-plasma and MIG? It sounds like the same thing, just smaller. I'm not sure why you'd need a counterweight; it doesn't seem like the micro-plasma head will weigh much, and there are no cutting forces to contend with. I don't think it would make much sense to move the whole bed, when all you need to do is move the head. I also don't think a long rubber belt would work too well in the presence of the arc welder; the UV radiance and metal spatter wouldn't do it much good. Rack and pinion would probably be your best bet, and keeping that mechanism sheltered from the arc mess would extend its life.

[laminated]

What's the difference between micro-plasma and MIG? It sounds like the same thing, just smaller. I'm not sure why you'd need a counterweight; it doesn't seem like the micro-plasma head will weigh much, and there are no cutting forces to contend with. I don't think it would make much sense to move the whole bed, when all you need to do is move the head. I also don't think a long rubber belt would work too well in the presence of the arc welder; the UV radiance and metal spatter wouldn't do it much good. Rack and pinion would probably be your best bet, and keeping that mechanism sheltered from the arc mess would extend its life.

That's very true about the belts. Initially, yes I thought it didn't make much sense to move the bed. Although plasma arc welding is one of the fastest welding methods. My gantry is using direct drive 400w servos with 10mm ball screws. I don't think that at higher speeds I would have much rigidity even with a steel Construction and the bed is essentially a static load moving only fractions of a mm at any time.

I'm not at all going for much penetration of weld. It's essentially hardfacing. So the rate at which that is possible to print as a bit unknown.