Looking for advice on a size

I am planning on doing 1" stainless rails, but unsure of what size I want my work area to be.
I plan to do wood and aluminum. I want to do some steel, but I gather a smaller work area would be better for this and I’d rather go larger, so I may build a second unit eventually.

I’m kindof thinking 29" x 24" work area. 3" z travel?

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Sounds fair for stainless rails! Might try lowrider for the second machine, if you have space? Welcome to the mad house!


If you are only working smaller pieces of metal, you can get some rigidity back by working in the corner and raising the piece up (stack it on a board, then fix the board to your spoil board). I haven’t seen a 29 in mpcnc cutting metal, but we did see a lowrider do it, and I’ve seen a 24in mpcnc cut aluminum with emt tube and impeccable cam. That said, the primo is still pretty new so I don’t think anyone is ready to say it isn’t reasonable. Go for it!

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I still don’t know. Maybe 24" x 12"?

Saving grace is if Its too big (or small) getting new tubes isn’t a huge expense.

Edit: I’m going with 12x18x3.


That’s a great size, especially with stainless. I’ve got an 8x10 that should absolutely be bigger.

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If you go big first you can always reduce size without need for buying more tube.

12x18 is a good size. I have had great experience with aluminum (mine is 14x18). If you haven’t started, I might recommend 14x18. Seems like a little change, but you may find you want something that’s actually 12 inches and it’s good to have a little extra room.


Thanks I will do that.

What is the best way to cut the stainless tubing myself? I have a carbide metal saw but I know that I will eat through my blade. I don’t have a working band saw. Can I use an EMT pipe cutter?

I saw a guy on youtube try a tube cutter on stainless tubes and he gave up. I don’t know much about metal saws but I would think that would be a better way to go.

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I’ve got a small chop saw I picked up from harbor freight for 30 bucks or so. It wobbles a little from side to side, so even making a jig doesn’t help a ton for accuracy, but it blasted right through that tube no problem. I did cut my legs a wee bit long anyway because I put them through a board that my feet are mounted to so it was NBD.

I guess if the tubes aren’t completely uniform, you can still measure the distance from the outside of the printed pieces.

The most critical tubes are the legs, and that’s just because they set the height so it’s nice if they are the same from side to side. You could also set that with a block or a tape measure.
All the other tubes can come a bit short or even hang out the sides. Once the feet are screwed down, it’s irrelevant.

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I would approach that from the application side - what is your expectable largest size of workpiece?

Unfortunately, I don’t know exactly what I plan to use it for yet.

If you’re thinking you might want bigger in the future, I’d get the belts longer to start with. It is easy to coil the unused length up and stick them in the ends of the frame tubes.

I was originally aiming for a 20" x 30" work area but ended up building it as 20 x 16 to fit in a convenient unused spot in my shop, rather than waiting for myself to build a new table for it to live on. I cut the belts to the originally planned size and I can rebuild to that larger size with about $10 worth of conduit if/when I get around to building that table.

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I used both a hacksaw and angle grinder w/ cutoff wheel. The angle grinder came out a bit cleaner. The legs were all within 1-2 mm. To set my height, I cut a spacer block the length that I wanted and placed it between each foot and corner piece and tightened them both down.

A hacksaw will cut that easily enough. The cuts are far from ideal, but a reasonable metal file will finish them beautifully.

My legs were the most difficult to cut well. Being as short as they are. I 3d printed a couple of pieces to help me. It’s a 2 piece jig that holds 2 1" tubes and has a flat surface 63mm away from the end. I used a metal file to smooth and square one end, then used the printed piece to make the other ends even and the same length. It took about 20 minutes to file the tubes down about 1.5mm to make them all even, including time to remove all the sharp corners from the metal, and I wasn’t going particularly fast.

Not being a fan of making extra work for myself, I wanted to be as sure as possible that I have as little difference in the length of my legs as possible.

The rails and gantries, I just wanted to make them the same length, and cutting the rails in pairs on the wobbly chopsaw was good enough.

This will do it: RIDGID 29963 Model 35S