Hypercube Evolution X-carriage - 10mm x 16mm sleeve bearings

thingiverse

This is a slightly modified version of the X-carriage for the HyperCube Evolution by SCOTT_3D. Since LM10UU simply won't fit inside the carriage without modifying the center-to-center distance on the original bearings, and the entire rest of the printer really wants 10mm rods, I've bored out the bearing channels to 16mm, which allows you to use 10mm ID x 16mm OD PTFE or UHMW sleeve bushings from McMaster-Carr. PTFE/UHMW sleeve bearings are best used for softer rod materials like aluminum or carbon fiber tubes, which are much lighter and plenty strong, but will get chewed right up by normal LM8UU or LM10UU with hardened steel bearing balls. Either bearing material will function better if lightly lubricated. Grease or oil may attract dust and grit, which over time will wear out the inside of the sleeve bearings and make the X-carriage not be properly constrained; however the sleeve bearings are cheap and quickly replaceable. Otherwise, a dry lubricant such as graphite powder may be desirable; the downsides to this are that graphite makes a horrendous mess and needs to be refreshed fairly often. My chosen method of lubrication was a bottle of SuperLube silicone/PTFE lubricant. The best way I've found to apply the grease is to stick a glob of it around the rods at one end, then use the assembled carriage with all 4 bearings installed to slide over both tubes end-to-end repeatedly, to ensure an even application of grease. This should embed a small amount of grease both in the surface of the rod and the inner surface of the PTFE sleeves (which are made of PTFE anyways). Move the whole thing to one end and use a shop towel or something to wipe the excess off the entire surface of the tubes, as well as the ends of the bearings. If the bearings are still a little stiff after all of this, take the bearings off and use them one at a time, on each rod, to figure out whether it's an issue with both pairs of bearings and rods, or just two bearings on one rod, like mine was. Use the small sanding wheel on a dremel to GENTLY hollow out the inside of the PTFE sleeve. You're going to be taking out just a tiny bit of material with each pass. Go slow, and test the fit with each bit of sanding. When you're done, use a paper towel rolled up to clean out the inside of the sleeve bearings, and re-do the grease steps above. At the end the carriage should just barely not be able to move under its own weight without the extruder installed, which leaves it tight enough to not wiggle but loose enough to not be terribly sticky during motion. The center-to-center distance is unchanged, so the outermost wall might be a little thinner than would otherwise be desired but I've yet to fix that. The rest of the model is unchanged. Additional parts required: 4x McMaster-Carr 10mm ID x 16mm OD sleeve bearings (recommended PTFE or UHMW): PTFE Sleeve: https://www.mcmaster.com/#2685T13 UHMW-PE Sleeve: https://www.mcmaster.com/#6657K13