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.
It looks like there may be a problem with the STLs in this release. :(
S3D complains about self-intersecting faces on all three rail models, and non-manifold surfaces on rails 1 and 3. It crashes attempting to slice them. Similar results with Slic3r PE and Pathio.
I haven't tried any of the other files yet since I wouldn't be able to get very far without them.