Plastic parts for the Prusa i3 kit I sell (http://www.emakershop.com/Seller=801).
Edits to the original (https://github.com/josefprusa/Prusa3, https://github.com/josefprusa/Prusa3-vanilla, extruder: http://www.thingiverse.com/thing:18379):
- minimal Prusa i3 x ends: zip ties, built-in adjustable tensioner and easy z height adjustor (http://www.thingiverse.com/thing:500550)
- increased height on y corners to avoid clearance issue with bed mountings.
- combined mounting holes for hot end -> extruder & extruder -> x-carriage (uses M5x40 bolts).
- strengthened and lengthened extruder idler arms.
- widened a 608ZZ bearing hole on the extruder a bit so it fits better.
UPDATE 2015-01-30: Added new endstop holders for v1.2 endstop with PCB - see http://www.thingiverse.com/thing:659231. Use i3xyze14 for these, and the older version (i3xyze13) if you have just the switches (can cable tie x and y to smooth rods).
Source files here: https://github.com/gcolbourn/Prusa3-SemiU
Note you can use the Split function in Slic3r to take just the parts you need from the build plate STLs provided here.
UPDATE 2015-04-24: Added extra parts needed for Box Frame (12mm plywood) version of i3: i3box_extras2.stl (note you won't need the z parts from the i3xyze14.stl file if you're building one of these).
UPDATE 2015-04-29: Added extruder body and idler for 1.75mm filament: eg175_4.stl (use 4mm OD, 2mm ID PTFE tube between hobbed bolt and hot end).