LowRider or MPCNC for 2'x4'

I’d like to be able to cut 2’x4’ sheets but I’m having trouble deciding between expanding out my existing MPCNC (with some reinforcements) or switching to a LowRider. If a LowRider is the way to go, could I get away with aluminum tubing given the shorter X-axis?

LR would be great at that size and won’t have any trouble with the 4’ axis. The MPCNC won’t work well at 4’. IDL about al, but my guess is non stainless steel would be better than al.

Hi Jeff, If the MPCNC had stainless steel tubing, would that be a better solution? I am tapping 1/4 20 threads into my conduit to insert 1/4 20 screws to make it rigid in the center areas. That way the gantry won’t cause sagging at midpoint and I don’t have to disassemble the machine to add the supports. I’m wondering if stainless accomplishes the same thing. I’m assuming that the supports would allow a longer XY. That could be an alternative for the Lowrider as well (though the stainless is much cooler to look at). What’s your thoughts on this?

I wouldn’t use aluminum. It’s soft and would be prone to wearing down. Eventually, you’ll have grooves and issues.

I’m tapping 1/4 20 threads into my conduit to stabilize the conduit along the XY axis. The 1/4 20 can be adjusted to lift up to prevent sagging as the gantry passes over the midspan. If an area for some reason is too high, drill and thread the hole on top then loosen the screws on the endcaps and twist the pipe over until the high point is facing down with the threaded hole on the bottom. I asked Barry to share his thoughts on this below. Anyways, it is a solution. If you are on the metric system, then adjust sizes accordingly. Best wishes.

Before the low rider, there were a few large MPCNCs. They worked, but it depends on what you’re making and the envelope of useful feeds and speeds is smaller. People used supports and Ryan made a stainless tube size. This was before the burly update and many were before the 525 update. So it is certainly possible. But if you’re trying to minimize cost and maximize fun, then a low rider is a better choice at that size, imo. If you’re already on your way with an MPCNC, then just build it and see. But Mike, I would suggest you start smaller to cut your teeth on something tolerant to beginner mistakes. Some longer tubes is all it takes to make it larger later.

FWIW, I’m not a mechanical engineer and I don’t have a good grasp on designing or working with metal. I haven’t built the later versions of the MPCNC.

Yea, I’d go lowrider for this. You might get away with it on a mpcnc with mid span supports, but that’s a maybe. Either way, you’re looking at a roughly 3 foot by 5 foot table. With the lowrider driving the length of the table, you only need 3ish foot long tubes.


Oh, don’t use aluminum tubes, they won’t last very long at all.

I agree. Lowrider if you haven’t started building anything yet. Our can make it any size. My next upgrade will be the Lowrider. I got the MPCNC to learn on first.

I just bought and assembled the MPCNC. I wanted the Lowrider but I decided there was a learning curve I needed to address first. And Stainless steel is expensive. MPCNC was the best choice. My biggest issue is learning to create the drawing files for my machine. That is my Achilles heel.

Home Depot has 36 in SS tubing that’s not expensive. That gives you 25 inches of usable work space.


I wanted the Lowrider for 8 foot by 6" carving of bed posts and making headboards. The SS I need is longer than 36" lengths. I wish.

Whaaaa??!! I’ve never seen stainless at the home despot.

yeah, wha???

I just looked (got me all excited), and I found only ordinary steel tube, 1" 16 gauge, 3-foot lengths for $13. I also found pipes in plumbing, not sure the dimensions or the material, but might possibly be a stiffness upgrade from EMT conduit.

No stainless steel that I could find.

Not that regular steel vs. stainless steel are all that different, but I don’t know if I would pay $13 for non-stainless. For that price (times 10 tubes) I would want some bling…

Usually the stuff at the hardware store is pipe anyway, so everything is measured by the inside diameter.