screwed sleeve bearings - replacing LM8UU, LM10UU

thingiverse

My K8200 started juddering severely. The linear bearings LM8UU, LM10UU from China had never really performed well. So I didn't want to replace them with just another set of low-quality bearings before trying printed sleeve bearings first. IGUS design is indeed famous for its innovative approach, but I never understood why it doesn't use helical grooves to increase stiffness in the sleeve cylinder. So I designed my own set of screwed sleeve bearings and am sharing them through this post. The STL file I'm offering for download contains four bearings that replace LM8UU with a height of 17.5 mm and diameters of 15.0/8.0 mm, and four bearings that replace LM10UU with a height of 18.5 mm and diameters of 19.0/10.0 mm. To customize the height and radii to your needs, simply open the SCAD file. Because of the helical design, the number of tracks isn't really crucial - I used six with a twist of 240° to avoid using support during printing. Print Settings: Printer: K8200 Rafts: Doesn't Matter Supports: No Resolution: 0.3 Infill: - Notes: I printed the bearings with PLA, and since my printer is well-calibrated, they turned out ideally - a bit too tight. To grind them to the right clearance, I used 8.0 mm and 10.0 mm drill bits with the drill slowly turning in reverse direction. Finally, I applied some aceton to seal the contact areas. The best clearance occurs when no slip or stick is noticeable anymore. For lubrication, I used silicon grease - avoid using ordinary grease or oil as thermoplasts don't like that.