MPCNC or Lowrider?

I’m at a crossroad here. I’m thinking of making a workspace of 1000x800mm which according to the calculator on mpcnc section, my conduits need to be approx 1400mm in length/pc. However, just read this on the intro mpcnc section:

“All axes can be any length you prefer, anything over ~3′ (1M) would be best to start with a LowRider CNC…”

Does that mean 1m in length of conduit or workspace?
And do you think it’s better for me then to go for LR3?
Starting from scratch which one is cheaper to build?

The MPCNC is cheaper to build, but is also only intended for ~600x600mm workspace max for optimal rigidity.

LR would be recommended for your stated work size.

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I personally like the lowrider for smaller sizes, too. That may not be a popular opinion.

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I’ll not be a lot of a help here, as my hobby is more to build the machines as actually using them. I’m currently building the Primo,buils already 2 MPCNC’s and my first ever build was the MP3DP to produce my first one, just to be able to do the plates for the LR3, I have already the LR2 as well, but I never liked a lot the tricks I had to do, to avoid the lateral movements on the Y-Axis. So build both…LoL

I’ve built 2 mpcnc’s and a lr2.

My mpcnc primo is 12.5 x 30. LR2 is 48x72.

I find the mpcnc to be more reliable and more repeatable for small parts it’s also faster. Pieces are are a bit harder to hold down as the bars get in the way some.

The lowrider is more open, Ryan fixed my biggest complaint from the lr2 which was the poor visibility. I find the z a little less accurate than the mpcnc especially on dados. If you are going to build a lr build a gantry that will fit the width of a sheet of ply. Then you can adjust the length if you need a bigger or smaller table.

They are both good machines I think that if I had to pick one I’d go with the lr.

From my personal experience with a large mpcnc (2’×3’ working area), go with a lowrider.


How come?

Care to share what tricks that wasn’t good? Something in the construction that you think would be good to update?

@moller.peter , a big factor will be what you plan to do with your machine and what accuracy you are expecting to hold. The conduit/tubes start to deflect under the Primo’s own weight when you get too big. That can cause vibrations/chatter especially if you are trying to cut harder materials. You can add supports at the midpoints around the perimeter but that doesn’t help with the Gantry Rails. You can also minimize this issue by locating your parts closer to a corner but that doesn’t help if the parts are too large.

I recommend taking a good look at the majority of the parts you plan to make and use that for guidance for your final size. My Primo is a little over 600mm square and I’ve only had one project so far that has been larger than ~400mm. I’m seriously thinking about reducing it’s size and making a 4’ LR3 for 1/2 sheet projects.

Good luck!


Thank you for that explanation!

I’d also say go LowRider. My Primo with 750x550mm was a little too big and had chatter in the middle.

Because the dust collection is figured out already, workpiece access is much more convenient, and the wiring is much simpler to make pretty, and if you decide you need a REALLY big cnc, I think it’s a matter of some strut plates, tubes, a few more printed strut brackets, and maybe an extension cord and lengthening some wires. Compare that to building a primo amd then needing something 3x6 or 4x8.

I was over at Tom’s checking his out (24x24 i think, or very close) and we got him started on aluminum. I left him to dial it in and after a while he ran it faster than I was running my 12x24 primo (cutting the same aluminum clamps). I’ve got some video comparisons in the lowrider forum I think.

I’m sure I could have run my primo faster than I did, not sure I could have run it faster than his lr3, very sure I couldn’t have run it significantly faster, i.e. fast enough to outweigh the advantages above. The primo is awesome, but the lr3 is REALLY awesome.