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'm glad you all like it. I'm sure the 2mm screws would be fine; they'd probably be a little loose, but it won't be an issue after you tighten them. The 3mm ones probably would not work since the holes aren't big enough. For the bearings, as long as they're sized such that the parts can fit through them without clashing, you can print whatever adaptors necessary to make them fit. I picked my bearings because they fit well with the scale of the engine and were readily available on the internet. And the parts are in mm. Looking forward to seeing it printed!