Lego Clock
The gearing is made fairly easy by the gears provided by Lego. I've built some demos, but need to start making some actual prototypes and start putting everything together.
Escapements:
- http://blog.makezine.com/2010/10/04/macdowall-single-pin-escapement-in/
- http://www.youtube.com/watch?v=83M3regQwuY
- http://www.youtube.com/watch?v=wBqNU1SsI04&feature=related
- http://www.youtube.com/watch?v=ysrbMk0v9rk
The workflow is basically: weights → escapement → minute driver &rarr 1/60th reduction. Both the minute hand and 1/60th reduction output to the face. The weights will probably follow a design similar to the knex escapement - the string will be wound around a larger coil to reduce variation in the power output. The weights will use a multiple-pulley system to leverage their limited drop distance. The output will go through at least one reduction before being regulated by the escapement.