Based on the EZStruder Knob by h3ss I added a notch to his design which mates with the notched portion of the stepper, allowing for better contact and more force to be exerted on the filament during hand extrusion. I also closed off the back as a purely stylistic choice.
Print with either ABS or PLA. No support needed.
Prototype Supply ABS
0.2mm Layer Height
2 External Perimeters