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 Reinforced bed bearing block features a flat mounting flange with no screw holes. PTFE 8mm bearing is just a cylinder, both are 48mm long or two LM8UUs put together. They can be scaled in the Z by any amount and they'll still work perfectly. I'm fed up with cheap Chinese LM8UU linear bearings that rattle, squeak, and make too much noise. Plus after a while, they're not as smooth as they used to be. These use 4mm OD PTFE standard 1.75mm bowden tubing you already have lying around if you've ever bought a hotend off eBay. I made these bearing blocks unfortunately I wasn't able to get them into the 15mm OD of LM8UUs, so it's not simply a drop-in replacement. 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. It's worth it to get it dialed in because once you do, they glide super smooth with no play and are silent. They make a slight wooshy noise on dry rods but a little oil and they're dead silent. There shouldn't 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 heavy bed. I haven't used these for very long so I can't speak for wear. But they're easy to replace if they ever do wear out. If you try this out please let me know and upload a make.