A homemade mechanical rolling ball clock.
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. (705 views)