LMU8 Y-Axis Brackets for Prusa i3 MK2/3 with Bear Full Upgrade

thingiverse

### Update 2019/01/09: All MK versions have been unified with the prefix "AllMK". The bottom part fits both old MK2.5 and MK3 specific versions. Additionally, an A360 link to the source files is provided below. I created bearing clips in the past for the Prusa i3 MK2 (also suitable for MK2.5 and MK3) as an alternative to zip ties and u-bolts for mounting bearings underneath the heated bed carriage of the Y-axis. However, because the original metal frame of the Prusa i3 series doesn't provide enough clearance to the linear motion system, the clips had to be minimal in design. This restriction made them less sturdy and lacking a cool feature I always wanted for the bearings: Replacing the bearings without disassembling the head bed from the carriage every single time. After switching the printer's frame to the Full Bear Upgrade, there is now enough space under the Y-axis to create more elaborate brackets. And here they finally are! The brackets consist of two parts. The upper part remains attached to the carriage and is guided into the correct orientation by using the carriage's notch and secured safely with two M3 screws. These screws are held in place by two nuts inside the bracket, which come in versions for hex nuts and square nuts. The lower part is then secured with four screws that attach to four nuts inside the upper part. Because of the design, the nuts will not fall out of the bracket at any time while the top mount is attached to the carriage, making disassembly easy. Furthermore, the four screws distribute clamping forces onto the bearing more evenly and reduce stress on the bracket. The brackets fit all lmu8-alike bearings with two notch-rings on the ends. You will need six M3x18mm screws for this, but shorter screws may also work. Do not use screws that are too long and which stick out of the top bracket because they will push against the carriage otherwise and cause problems. Additionally: Due to the design of the brackets, the bed will be raised by about 3.3mm. If you haven't changed the Z-steps in your firmware settings, the Z calibration procedure should work without issues! The source files for Fusion 360 and many other formats are available under: https://a360.co/2Fk3R7w Please read my print settings recommendations and post-print section below. Your opinion on this design and suggestions to make it even better is appreciated. Please also take a look at my other designs, printer parts, and tools. If you like to support me and my work, please consider following me on: * Thingiverse * [MartinMajewski.net](https://www.martinmajewski.net) * [Twitter](https://twitter.com/MMajewskiNet) * [Instagram](https://www.instagram.com/martinjmajewski/) * [YouTube](https://goo.gl/QJTQKv) Please also consider buying your next gear via one of the affiliate links provided below. ### Products related to this project - Ruthex/igus set of open and closed solid skew compensating bearings: [Amazon.de](https://amzn.to/2AHX7Nx) [Amazon.co.uk](https://amzn.to/2QBxymn) - igus RJ4JP-01-08 drylin Bearings: [Amazon.de](https://amzn.to/2RAZvzn) [Amazon.co.uk](https://amzn.to/2RiJv5K) ### Generic Affiliate Links - [Amazon.de](https://amzn.to/2KNFFO1) - [Amazon.co.uk](https://amzn.to/2lY9bSU) - [eBay Germany](https://rover.ebay.com/rover/1/707-53477-19255-0/1?mpre=https%3A%2F%2Fwww.ebay.de%2F&campid=5337986926&toolid=20008) - [GearBest.com](https://www.gearbest.com?lkid=13789568) Sending a tip over Thingiverse will buy me some coffee and a new spool of a filament to stay productive.