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 just printed this and it worked fairly well... except for one thing. When I was breaking it apart, I managed to break the bottom ring (the one with the half sphere studs) apart from the center in three of the four connection points. I superglued it back together and it functions just fine. With a little graphite or some sort of lubrication, I think it would work pretty smoothly.
So, there probably need to be some reinforcement of the area where the bottom ring attaches to the center. I printed it with 3 bottom/top layers and 2 shells.