SquareBOT extruder

Archive model. Not recommended for repetition.
New SB extruder: https://www.thingiverse.com/thing:2658691
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Direct extruder for my SquareBOT 3D printer.
Fits for Nema16/Nema17 stepper motors with planetary gearboxes any gear ratios.
My stepper motor is Nema 17 with planetary gearbox 5:1 gear ratio.
(part # 17HS13-0404S-PG5 from StepperOnline).
Nema 16 motor (part # 16HS13-0604S-PG5) has an identical size gearbox, except shaft diameter (8mm).
I'm going to use short-dista