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.
Have you considered shifting the handle to one of the wheels, rather than the gear between them? It seems like the mechanism would "feel" backwards, in this configuration. I like the general design and its simplicity, however. Nice work on the gears, as well.
Now we know what the Mythbusters square-wheeled truck should have driven on – nothing but speed bumps!