Ron's Compact Extruder

thingiverse

The printer's extruder, as per Josef Prusa's i3 design, is not this one; it can be found at https://www.thingiverse.com/thing:24219. A direct drive extruder, designed for use with a Minebea geared stepper motor, a Makerbot drive wheel, and a MakerGear GrooveMount (or similar) hot end, this is an improved version. In search of the best extruder, the designer has fought clearance issues and tried various gearing systems. The current design meets these criteria: torque to drive 3mm filament, reliability with no slippage or lost steps, size for full width bed usage, easy setup with no bolt tension adjustment when changing filament, ease of maintenance without disassembling the extruder, and compatibility with MakerBot MK7 drive gear or arcol Hyena 11x5 drive wheel. The required Minebea PG35L-D48 geared stepper motor, a MakerBot MK7 Drive Wheel, a 624 bearing (4x13x5), 2 M3 x 25mm Socket head screws, 4 M3 x 35mm Socket head screws, 1 M4 x 20mm Socket head screw, 6 M3 washers, 6 M3 nuts, and a M4 nut are the extruder vitamins. Choose your carriage style, print the parts, and use SFACT for slicing. Calibration involves checking steps per mm using http://calculator.josefprusa.cz/ and adjusting firmware accordingly. A compact carriage assembly also requires igus bushings and specific M3 screws and nuts.