Archive model. Not recommended for repetition. New SB extruder: https://www.thingiverse.com/thing:2658691

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-distance E3D hotend, so the bottom side has the mounting groove.
SquareBOT 3D printer: http://www.thingiverse.com/thing:480008
News:

• 04.01.15 I've printed it, and it works perfectly. I'll upload the photos soon.
• middle_part_v2 rev.03-01-15
• mount_v2 rev.03-01-15
• added mount plate for MGN12H block carriage

The knob part needs a support and thick walls.
Fan 40x40x20mm.
You need also:

1. Extruder gear (feeder roller) bore ø6mm (my was ø5mm, just ream it up to 6mm).
2. V625ZZ ball bearing (V-grooved).
3. 6pcs bolts M3x30mm.
4. 2pcs bolts M3x25mm.
5. 1pcs bolts M3x20mm.
6. 1pcs bolt M3x10mm with M3 hex nut.
7. 1pcs 16mm countersunk head bolt.
8. 10pcs M3 plain washers.
9. 6pcs M3 inserts (ø5x8mm)
10. 17mm shaft ø5mm for ball bearing.
11. Spring ø7.5 x 8.1-15mm. My from dryer clips (Ikea PRESSA series).
12. Needs insert a little PTFE tube ø4mm under the gear as a filament guide.