Byteborg's Direct Drive Extruder (3mm)

thingiverse

This redesigned direct drive extruder offers a low-profile build that maximizes effective print height on your Prusa while maintaining simplicity and ease of use. Its spring-loaded mechanism allows for easy load/unload, and it's straightforward to construct. The source code is available at https://github.com/byteborg/mendelparts/tree/master/parts/direct-drive-extruder, so feel free to experiment with it. Version 0.2 includes a part to hold the bearing in place (bearing_clip.stl), while version 0.3 features a sturdier extruder body. A crucial tip: print the roller lever in ABS, and make two of them since PLA is too brittle for this task. An updated public service announcement recommends using DRV8825 stepper drivers for added torque. The Bill of Materials (BOM) includes a NEMA17 stepper motor with maximum torque, a 5mm bore x 8mm outer diameter pulley, four M3x30 screws, an M3x40 screw, a strong spring, assorted nuts and washers, and two 608ZZ and 625ZZ ball bearings. Assembly instructions are provided, along with guidance on adjusting the pulley and lever tension. Configure firmware with 420 steps/mm for Marlin and RAMPS boards with DRV8825 drivers in 1/32th microstepping mode. After loading the filament and fine-tuning the spring tension, enjoy stress-free printing!