Prusa Mini Extruder Section - BMG Version

thingiverse

Prusa Mini Extruder Section - Using BondTech BMG 3:1 Dual Drive Gear System. I designed this using the original Prusa Mini Files and the model of the BondTech BMG by MarcoZ76. In my build of the Prusa "Midi" (my slightly larger Mini build at 220x220), one of the hard-to-find parts that Prusa made is the Extruder Gears. The Titan and BMG stuff are the same ratio, but different physical size. I also didn't like that they went away from the proven dual-drive BondTech gear system that works so well in the i3 series - so here is my solution to upgrade your Prusa Mini to a Bondtech BMG! Not only is it easier to find these gears - original ones or clones, but you are adding the undoubtedly better filament grip of the proven dual gear system, while keeping the torque and resolution of the 3:1 gearing! This was created and released here prior to Bondtech's own Prusa Mini BMG as well as any other sold at retail. My design still has provisions not seen on others such as filament runout switch mount and handling the wire bundle in a way less prone to blocking the X carriage and bending the wire bundle sharply. Although it is not the same part as Bondtech sells at retail, it is still based on their gearset design. This design should only be used for private use, and not commercial purposes - Bondtech SE sells a similar product at retail. UPDATE 2/23/20 - I updated the main base to provide clearance for Z-Axis, added Revision Marks to main body pieces and cleaned up some excess material. Also, I added Zip-Tie points for the wire bundle going to the Hot-End, as well as a pinch bolt / mounting bolt for a Filament sensor (instead of just letting it dangle off the end of the Bowden tubing). UPDATE 6/8/20 - I adjusted Zip Tie Holes for easier fitment, and added more material at mounting base to provide clearance at full Height Z Axis. Verified holes aligned with newer R4 Z axis parts (they still do - nothing had actually changed there in relation to mounting the extruder, but I received a comment that it was a concern so I checked!). UPDATE 10/18/20 - I added Sensor Bracket back into STL file - was inadvertently removed on previous update! Uses the standard "Microswitch" type that are common on Ender type printers with 20mm spacing. This is still a work in progress - I will post any updates as I find them.