3mm Direct Drive Extruder / Bowden Extruder

thingiverse

This 3mm direct drive extruder is compatible with Prusa Mendel and similar printers, offering enhanced torque for reliable 3mm filament extrusion through a 0.35mm nozzle. Assembling it requires M3x12 screws (33/4"), 1" 4-40 screw and nut (x2), 2625z bearings (x2), and a #10 brass or steel spacer, 5/16" OD, 3/8" length for the drive gear. The extruder can also be used as a bowden extruder by running filament through 1/8" teflon tubing threaded into an M5 nut held by the nut trap. To ensure optimal performance, consider adding heatsinks to both the stepper and the extruder stepper controller. This extruder has been successfully used with a DIY drive gear, featuring upgraded parts for stiffer filament compressor arm and fully supported stepper shaft. Calculated steps per mm (132.285) are close to the mark but require calibration. The test piece printed exhibits expected quality. For reverse operation, simply run it in reverse.