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.
The springs are homemade from steel wire. I describe how I made them in the instructions. Another thingiverse user made his from 1.75mm PLA by designing and printing a mandrel, wrapping the filament around it, and submerging it in hot water.