A belt driven Bowden extruder for NEMA 17 motors and GT2 belts.Designed to attach to my Prusa i3 top bracket but should fit any printer with a flat surface about 45 x 30mm that can have screw holes drilled.

This unit uses GT2 belts and pulleys for a 1:2.5 reduction. Designed for 1.75mm filament, this has a filament guide and shaped holes for easy filament loading.

I used a white tyre paint pen to paint white stripes on the belt every 10 teeth to make it easy to monitor the feed rate etc.

Update 25 Oct 2015: v1.03 files replaced by v1.04. The holes for the locating pins on the upper bracket were not deep enough so have corrected.

Other parts designed for my printers include:

• http://www.thingiverse.com/thing:1959901 (GT2 belt clamp (Prusa Y-axis)
• http://www.thingiverse.com/thing:1937232 (Arduino Mega and RAMPS v1.4 case)
• http://www.thingiverse.com/thing:1905409 (Prusa i3 steel 10mm upgrade)
• http://www.thingiverse.com/thing:1959974 (Prusa i3 Steel Y-axis motor mount)
• http://www.thingiverse.com/thing:1991116 (Prusa i3 Steel X-carriage)
• http://www.thingiverse.com/thing:1991117 (E3D Chimera / Cyclops mount)
• http://www.thingiverse.com/thing:1994413 (dual E3D Thermocouple amplifier board - housing)
• http://www.thingiverse.com/thing:1090661 (Belt driven Bowden extruder with 1:2.5 reduction)
• http://www.thingiverse.com/thing:896676 (enclosure for SevenSwitch FET)
• http://www.thingiverse.com/thing:922455 (8mm Z-axis leadscrew bearing holder)
• http://www.thingiverse.com/thing:922309 (Z-axis NEMA 17 adjustable endstop bracket)
• http://www.thingiverse.com/thing:899607 (cable chain)
• https://www.thingiverse.com/thing:2334269 (LCD housing)
• https://www.thingiverse.com/thing:2377049 (PSU cover)
• https://www.thingiverse.com/thing:2395715 (Chimera & Zesty Nimble drive cable spacer)
• https://www.thingiverse.com/thing:2407651 (Chimera Zesty Nimble X-axis set for i3 clone)
• https://www.thingiverse.com/thing:2436869 (A dummy NEMA 17 motor to hold the 5mm shaft)
• https://www.thingiverse.com/thing:2748978 (A Duet WiFi housing)
• https://www.thingiverse.com/thing:2749324 (A layer fan for the Smart Effector)
• https://www.thingiverse.com/thing:2814068 (A Sannce I21AG mount for 3D printers)
• https://www.thingiverse.com/thing:2844881 (A cooling duct for a Noctua 40mm fan on a Duet Smart Effector)
• https://www.thingiverse.com/thing:2846955 (A quiet BerdAir type pump mount)
• https://www.thingiverse.com/thing:3333609 (A Raspberry Pi case with 40mm fan)

For avoidance of doubt, this item is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. See http://creativecommons.org/licenses/by-nc-sa/4.0/ for more details.