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.
That's unfortunate that it's not available anymore. Fortunately, any free-spinning open bearing in the 6003 size will work. I only picked that particular one from that site since it was cheap. I'll try to find another source for it and update the link in the description.