MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
I've just uploade a 6mm spacers set for standard Prusa i3. Just put between the frame and the Z axis (top, bottom, right, left) supports. The stepper motor I use is exactly the 42BYGHW208: 43mm x 43mm x 33mm (H x W x D).
Ciao. ... :-)