Here is another 3d printable watch from 3D proto. It is controlled by MSP430 microcontroller and has a circular display that shows time / date with 12 bi-colored LEDs around the face with one status LED for p.m. - a.m. time.Watch strap is printed in felxible PLA and 3d printer is used to drill watchface holes.
Hopefully designers will publish the electronics schematics, but it should be easy to recreate if you have some experience with electronics.
Here is a video of the watch and development process:
Here is the project homepage (in German):
For an Open Source warch project which is much better documented take a look at: