BondTech Mini Extruder with PC6-M6 fitting for 2.85 mm filament

thingiverse

I'm reusing 2.85 mm filament from my Ultimaker 3E for my home-built printers and I needed a smaller Extruder compared to previous designs, such as https://www.thingiverse.com/thing:2897762 and https://www.thingiverse.com/thing:2758025. This design uses a Trianglelab dual drive gear kit cloned from Bondtech for 2.85/3.0 mm filament with an inner diameter of 8 mm. The extruder design is based on the original free Bondtech Mini extruder, but it's completely redrawn from scratch. The design includes a belt reduction of 2:1 (20 teeth pulley with a 5 mm shaft diameter and a 40 teeth pulley with an 8 mm shaft diameter) and a GT2-110 6 mm closed loop belt. Inside the parts, two bearings (F688ZZ 8x16x5 mm) are used to secure the 8 mm shaft made from a linear guide rail. To secure the Bowden tubes, PC6-M6 tube connectors are screwed into the top housing. An overview of the parts is given, including some 35 mm Allen key bolts to secure the top and bottom housing to the stepper mount (requires 4 M3x5x5 mm brass knurled inserts). A standard metal NEMA17 stepper mount is used to attach the complete assembly to aluminium extrusion profiles. Yellow PLA is used for the images, while the end product is printed in black ColorFabb PETG.