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.
Did you increase the thickness of the duct walls on the 40mm version? I printed w/ the same settings as the 50mm version (ABS 0.2mm layer height), but they are the same weight despite the size difference. The 40mm does seem indestructible, but the original thickness seemed like the perfect balance of strength/weight.
The new angled motor supports are FANTASTIC!