This looks like a really awesome mod. It appears to solve all the problems I'm having with extrusion on my Replicator 2. I am trying to print these parts to fix my Replicator 2 Extruder but after I downloaded the .stl file for ExtruderR.stl, I tried to slice it using the MakerWare app. When I try and print it, the print head moves to the center of the platform and then completes the build. Nothing gets printed at all. Is there something special I have to do in order to get this stl to print? As you can tell, I'm kind of new to this.