Spring Loaded Extruder Upgrade Mbot

thingiverse

This filament drive replacement is ideal for printers with smaller-than-Makerbot original drives. It's based on Thingiverse's designs but more compact at 42x29x15.2mm for Mbot3D Cube. The design files are in SW2012, and you'll need an M4x10 countersunk screw, an M3x8 one, a 4mm-hole, 13mm-diameter bearing (from the printer), and a 9x15mm spring (from a paper puncher). Note that heat insulation from the stepper motor may be inadequate. The model has a 0.2mm layer thickness, 1:1 scale, and 100% fill with external and internal supports; it's designed for 0.2mm output tolerances on inner and outer dimensions.