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 uploaded a file: "groups printable.zip" there you find the grouped parts:
(flexible filament .stl , hand wrist .stl, 100 filling.stl and proximal.stl)
you may find it useful