Prusa Bear-BMG fusion (indirect filament sensor) for MK3 / MK2.5

thingiverse

This Bear BMG extruder is a combination of an excellent extruder made by Pekcitron (Bear Extruder) and the Bondtech BMG 3:1 . I tried to integrate an indirect filament sensor with a magnet, based on this design: https://www.thingiverse.com/thing:3241561 RaavHimself's very smart design! To use the indirect filament sensor, you need a MR105z bearing (5x10x4) and a round neodymium 8x3 . No firmware changes are needed! You also need one number 1 thread insert to fix the extruder bottom to the X carriage on the left upper side. I'd like to thank all the people who have developed better extruders, especially Pekcitron, RaavHimself, and Lee0101. I'm grateful to Eric Clinedinst for helping me find the first issue. Here is the BOM list for the internal parts: 1x 5x10x4 (MR105z) Bearing for indirect filament sensor 1x Round neodymium 8x3 https://www.amazon.com/dp/B075FKTCZG/ref=cm_sw_r_cp_apip_pkFCQPIVjH3OA 2x 5X8X2.5 Bearing https://www.bondtech.se/en/product/ballbearing-5x8x2-5 1x Shaft Assembly https://www.bondtech.se/en/product/shaft-assembly 1x Motor Gear https://www.bondtech.se/en/product/motor-gear/ 1x 3X32 mm Shaft https://www.bondtech.se/en/product/shafts/ 1x Thread insert https://www.bondtech.se/en/product/thread-inserts/ 1x Thumbscrew Assembly https://www.bondtech.se/en/product-category/spare-parts/thumbscrew-assembly/ 1x Push-Fit Connector (or you can model in Fusion to adapt PC4-....) https://www.bondtech.se/en/product/push-fit-connector 1x M3x50 screw https://www.amazon.com/dp/B075FKTCZG/ref=cm_sw_r_cp_apip_pkFCQPIVjH3OA 1x M3x30 screw https://www.amazon.com/dp/B075FKTCZG/ref=cm_sw_r_cp_apip_pkFCQPIVjH3OA I've made several updates to the design since its initial release. Here are some of the key changes: **Update 1:** I moved the e3dv6 a little bit more down, increased the filament path, decreased the diameter for the filament sensor screw hole, and made other minor adjustments. **Update 2:** I added a hole for a square nut to fix the lever instead of the thread insert, and added a hex nut to fix the fan support. I also added a square nut to keep better in place the screw for the bearing pressure. **Update 3:** I added STL files for the MK2.5 X-carriage and re-uploaded STEP files for the MK3. **Update 4:** I added a PDF file of quick assembly photos. **Update 5:** I added .STL files for cable guide back part A and part B, thanks to Gabe Condrea's suggestions. **Update 6:** I updated the assembly guide, thanks to repvik. **Update 7:** I added a version of Extruder bottom with a PC4-M6 and a Lever with a 2mm recession to solve the issue with short screws if you're using the original Thumbscrew Assembly.