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.
This is explained in the instructions provided however the difference is slightly greater internal clearances between the parts. This was provided as not all slicing apps and machines print the same so, for members with machines that aren't as precise / accurate than others, the loose version should ensure the parts don't fuse during printing... so it will spin as expected.
I hope this explains what you need...