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 - Tried this guy, way too much friction. Particularly bad is that the more torque delivered to the escapment, the higher the friction.
- http://www.youtube.com/watch?v=ysrbMk0v9rk
- http://www.youtube.com/watch?v=teLNrq8OVsc&feature=related I like the one at the end of this video
- Now I'm thinking an Arnfield escapement would be best, the one (pseudo-grasshopper) I was using before was too bulky
- Flying Pendulum would be cool: http://www.youtube.com/watch?v=C6k9hXkv_Ec
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.
Just did a quick calculation and the weight should be (in blocks) 12 wide, 14 deep and 11 tall. That will be 10 pounds. It's also about 1800 bricks.
To do a full clock case would take about 16,000 bricks. To do a more basic 4-post design would be 6,000 bricks.