Print all three parts as no part is interchangable with the original due to the alterations I made, . 11/26/2014 - Added a fixed version of the bearing mount as the M4 had a missing fillet and was slightly off center for the M4 bearing screw hole. . I decided to spend all day yesterday backwards engineering the mrice version ( http://www.thingiverse.com/thing:501755 ) of this and found a few places I didn't like as well as holes that were simply too large (like 4.4mm stepper motor mounting holes instead of the customary 3.6mm holes though some 3.6mm holes were already used in other spots). I also beefed it up some in the spots that needed it. . Another thing I changed was the angled filament hole as any bending of the filament right before it enters the hotend is not something I liked so I made the hole straight all the way from the top to the hotend. . I have not mounted this yet as my parts are still on the way but I did want to release the source so anyone who wanted to could also modify it.