Looking for LowRider CNC Z-Axis Mod: Linear Rods / LMUU Bearings instead of Linear Rails?

LowRider CNC Hardware Development
1

Hey everyone,

I’m looking into the Z-motion system for the LowRider and want to know if anyone has successfully implemented or found a community remix that uses smooth linear rods and LMUU bearings instead of the standard profiled linear rails.

  • Why? I have high-quality linear rods/bearings on hand that I’d like to put to use if possible.

  • The Goal: Avoid buying new linear rails if a functional rod-based Z-axis mod already exists.

Does anyone have a link to a STLs/STEP files for a remix like this, or has anyone tried it and run into rigidity/flex issues? If no one has done it, I’ll look into modifying the YZ plates and XZ blocks myself (likely using 12mm or 16mm rods to prevent flex).

Appreciate any links, threads, or insight you can share!

2

I’d refrain from using them, they are not as great as the “normal” linear rails in my experience. The price difference is also not that much. :slight_smile:

3

He is talking free because he already has them

4

If it were me, I’d be using the stock configuration for simplicity and ease of support etc. and then save the linear rods for some other application.

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5

From an engineering standpoint, those guide rods will cause you more problems than you save in money. The ball bearing linear guide rails are constrained in 3 axes, whereas the linear rods are anchored only at the ends allowing them to flex in the middle along a parabolic curve. So whatever your project is that you’re cutting will have artifacts based on that deflection. This gets worse the heavier the gantry is.

You can do it, but you likely won’t be happy with it. Hope this helps.

6

Thanks for the reality check, everyone. James, that point about the parabolic flex and end-anchoring makes total sense for a CNC load. I’ll stick to the stock linear rails for this build and save these rods for a lighter 3D printer project. Appreciate the advice!

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