Moved my site. Will fix them today.
I see all the pictures in my threat … 
I remember this build, was this the build that eventually stopped using the mpcnc frame? And just to be clear, the “dangerous” build I was referring to was mounting a tube vertically to the z axis.
Yes, sorry. That’s what I meant. One stepper for each axis though.
Was chatting with a local MPCNCer just now. Thought I’d pose this here too. Thing I don’t get is that the CO2 lasers I’ve been seeing typically use fixed height X and Y rails and most do not have driven Z platforms. So the lasers just blast through whatever thickness is set under them. It could be far more efficient with a driven Z bed so you could maintain optimal focus distance per pass. Or maybe at these powers precision doesn’t matter as much? Come to think of it, my 15 pass run on the 2.8 didn’t step down (even though I had told it to) and it still cut…
They have a sharper focal cone, but just a ton more power per area as well.
it depends. my laser doesn’t have an adjustable Z, but I have an adjustable lens holder. It also depends on your focal length of the lens. The longer the focal length, the longer the focal depth (area the beam is concentrated the most). You want to set the focal point in the middle of the material so all the energy is in the middle of the cut.
I have several lenses. 1.5" focal length for engraving, and also a compound (double lens) setup, 2.0" is good for all around, and a 4" for if I have to cut something farther down than usual.
The goal is to cut in one pass. For these lasers, the more passes you take, the more charred it gets, and the bigger the cut kerf gets. on my big co2 laser, I’ve tested up to 1/2" poplar ply in one pass.
But generally, any chinese laser bigger than a K40 like the overdriven 50 watts already has an adjustable Z table pretty much.
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Thanks Tom!
Will the super long belt required for a CoreXY setup cause any issues with accuracy and/or speed? And what stepper will be up for the task without burning up the drivers on the Rambo (Rambo can run GRBL I assume?)? I was giving serious thought to a wide but not deep buildup much like the Further Fab. However I’m thinking a pass through enclosure such that (if set up properly in my shop) I could theoretically work a full sheet of plywood through. That means 4 feet of X travel and maybe 16-18 inches of Y. I assume I’d run the super long belt on the X axis?
Second - what’s better in terms of friction and weight. Linear rails or vrollers?
v-rollers will almost always have less friction. You do eventually run into belt length issues for core xy. Not sure what the actual length is.
I was doing a bit more reading last night (on the double decker thread) and it sounds like best plan might be to jump up to 10mm belt at a minimum.
What’s the material? Is that plywood? What’s the thickness?
I really need to do more work with my little diode laser. So far I’ve gotten a few good etches, but haven’t tried cutting anything.
Up here (Canada) they call it rotary mahogany. It’s got thin veneer plys on the outside and some core inside. I’ve been meaning to delaminate a piece to see if the core is a natural wood core or some sort of man made particle core. In any case it 1/8 thick. I also had some birch ply laying around. It’s the same makeup - three plys with a thicker core than outer layers. Cut through in about 17-20 passes at 2mm/s!
The Nancy Drew pieces are the 1/8 material and it took six tries to get two clean cuts. Seems the woods have variance understandably. Or maybe it is where the laser couldn’t pass clear through because of the supports I had under the materials (fender washers).
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Ok. We have similar plywood around here too. 1/8" thick is pretty good for the smaller diode lasers from what I’ve read. I’ll have to give it another shot, although I doubt my Chineese 3.3 laser really puts out a full 3.3.
Nancy Drew? That first image had me thinking Fred from Scooby Doo, complete with ascot… But then the last image is certainly more Daphne, ergo: Nancy Drew. 
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I’m back in laser dreaming over here. I just saw a multi purpose carriage assembly on AliExpress that used one of those steppers with a through-axle. I’m not sure what the proper term is. Anyway - wouldn’t this solve the fear of having two steppers on the y axis? I imagine I need to make sure it’s a stronger stepper?
Seems like a winning discovery to me, no? See the stepper setup on the right side in the pic.
This looks exactly like the frame inside my K40 40w laser, so yup 
So you have only one stepper driving each axis then? (Just confirming).
What size steppers are in there, do you happen to know?
For what it’s worth, here’s my laser with a nema 17, at 500mm/s, 10,000mm/s² acceleration, and why mounting a tube vertically on the gantry is a bad idea. Nema17 is the same as the ones for the MPCNC. Y axis is also driven by one nema 17, and my x axis is a little over 1200mm wide.
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Wow. That’s fast.
Thanks for keeping the thread alive. I haven’t forgotten about this but the current exchange rates have me waiting a bit while I consider other issues surrounding this project - primarily build size, shop space and most critically major dust issues in the actual shop. I feel like a machine like this would have to be built in the office (vented outside) or in its own “laser shed”. There’s no way around the dust in the shop.
If you’re willing, would you mind sharing more pics of your setup? Frame materials, stepper configuration (is this CoreXY?) etc. The only real revelation I’ve had since this thread was the thought of using single dual shaft steppers.
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