PTFE 8mm Rod Linear Bearing (LM8UU "Replacement")

thingiverse

Inspired by Visidor's 2020 aluminum extrusion slider, using the same PTFE tubing: https://www.thingiverse.com/thing:1721338 reinforcedbedbearingblock features a flat mounting flange, with no screw holes. ptfe8mmbearing is just a cylinder. Both are 48mm long, or two LM8UUs put to eachother. They can be scaled in the Z by any amount and theyll still work perfectly. Im fed up with the cheap chinese LM8UU linear bearings, so rattly and loud and noisy and.. not quiet. Plus after a while they are just not nearly as smooth as they used to be. These use 4mm OD PTFE, standard 1.75mm bowden tubing you already have lying around if youve ever bought a hotend off ebay. So I made this. Unfortunately I wasnt able to get it into the 15mm OD of LM8UUs, so its not simply a drop-in replacement, but maybe someone more creative than me can figure it out. I had to scale mine up to 1.06 to get the perfect fit, but printers vary so your results will too. Its worth it to get it dialed in though, because once you do.. Glides super smooth, with no more play than the LM8UUs (not much at all) and best of all, SILENT. They make a slight wooshy noise on dry rods, but a little oil and theyre dead silent. There shouldnt be any real pressure on the PTFE, only the load from the weight of the bed/gantry you use these for. In my case, a rather large and heavy bed. I havent used these for very long, so I cant speak for the ware. But theyre easy to replace, if they ever do wear out. If you do try this out, please let me know and upload a make.