A homemade mechanical rolling ball clock (english, deutsche Version: http://youtu.be/wJK0AjOHbzk)
The clock runs for 12 hours, driven by a weight of 2.5 kg sinking approx. 1 meter during that time..Every minute a marble is lifted up and goes down a marble run with three flipping traps that count marbles for minutes, five-minute-steps and hours.
The timekeeping element is a second-pendulum with a pinwheel escapement.
The clock achieves a drift of less than 1 second per day.
Stereoscopic photographs of the clock on Google+: http://goo.gl/dWnkb8
– Wood (mainly remains)
– Plastic gear wheels
– Brass wire (1.3mm, 3mm)
– Steel wire (bicycle strokes)
– Old flat iron