UNIT3D's LM8UU Linear Bearing

Replacement Linear Bearings for 8mm rods of Prusa printers

• Minimal friction surface
• Clean outside, no grooves or logos

Print time: 39 minutes

• No support
• 0% infill

The 3D Models found online where pretty low-poly and had other features I did not like, so I created my own.

Included are 4 variants from 8.1mm to 8.4mm inner diameter.

(This bearing removed my Print-Bed rattling)

Print instructions

Printed with Prusament PC Blend Jet Black, in my case, the 8.2mm ones were the sweet spot (with 0.15mm layer height and Ruby nozzle).

You can slice them in half for test-fit prints (and still have them nicely chamfered on both sides on the inside).

Although it was a little tight at first (starting to move the bearing was hard, but once moved, it moved smoothly with a nice tight fit).

If you hit it with your fingernail and can't make it rattle on the rod it is perfect, note that a tight fit might include initial failure of XYZ Calibration, in my case I had to retry a few times.
Basically you want to make the fit tight enough so you have to wear the bearings somewhat first to really make them run smooth and easy.
After printing 3 more bearings for spare, My MK3S print bed is now supper stable and rattle-free, and it runs easy enough to not cause Y calibration (Auto Home) to detect endpoint before it actually hits the endpoint.

Here are 2 videos from before and after the mod:

Edit:
After using my printed PC blend bearings for some time, the print bed started to vibrate when it moves at a certain speed.
I will print the next set of bearings with the smallest diameter of 8.1mm and bore them up with an 8mm drill to get a better fit with more surface contact.
Printing them with 8.2mm and using them without any post-processing might fit tight at the beginning, but after some wear, they getting too loose.