Prusa Bear-BMG Fusion for MMU2s

thingiverse

I revamped Marco's original design to adapt changes for MMU2s. The MMU2s adapter was originally created by Joe Prints at https://www.myminifactory.com/object/3d-print-prusa-mk3s-mmu2s-ir-sensor-mount-bondtech-bmg-89362. I also incorporated some enhancements that I thought would be beneficial. - I eliminated the indirect filament sensor and established a straight path to the extruder. - I designed funnels for filament inputs (Festo and Gears). - I added a lid to fine-tune sensor placement and allow users to remix for different Festos. - I reduced the distance between the front and back of the gearbox, raising the bearing platform. This closely resembles the official BMG gearbox and minimizes front/back shaft movement. The bearing also acts as a spacer now. - I replaced the threaded insert with a square nut. - I narrowed the filament path (2mm). Be sure to drill out burrs from the path after printing for optimal results. **Changelog** 4/14/2019 - I moved the sensor 2mm to the left to account for a slight angle of the unloaded door. This required altering the extruder bottom. If you've already printed the bottom, simply shave the left lip that holds the lid in place. Tested the sensor and it works great! Make sure to go to support -> sensor info and ensure 0 is unloaded and 1 is loaded. 4/18/2019 - I made the clamp for the hotend and PTFE tube more traditional like the official BMG, reducing the chance of kinking the PTFE if not properly seated. This is a big deal for filament load/unload. 4/18/2019 - Rev 2. I beveled the extruder bottom hotend clamp to make hotend placement easier, especially true when not removing hotend cartridges. **Other** I also use custom BMG firmware, but need further testing: https://github.com/bgiot/Prusa-Firmware-BMG. I think it helps with purge as length is different and unload current is raised. If you're switching from Marco's design to MMU2s, print out the lever, extruder bottom, extruder top, lid, and sensor cover. If your x carriage has a threaded insert from the last design, it should work fine! I printed this using Marco's original design with Atomic Carbon PETG at .15 layer height and achieved excellent print results. I fully printed and tested it, and load/unload is great; just need to dial in my config.