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 have an 'accessory' in mind for displaying the minutes: a balanced marker that rides at the bottom of the large gear, using gravity to turn it synchronously with the drive gear. The cool thing about this approach is that it's purely an add-on: none of the other parts need to be modified, so it could be added later. (If it works, that is!)