Algodoo

An improvement on my old timers that use stored spring energy to run a system of gears. This one has a second hand and a minute hand as well as an escapement to improve the accuracy. Doesn't run perfectly on all computers, but should work great at 60FPS, 100Hz sim frequency.

It also has a ratchet mechanism so that you can charge the spring inside without touching any of the other gears. I would have also added an hour hand but I didn't feel like investing that much more time.

Press 1 to charge up the spring and lever inside of the timer. Press 1 again when it stops charging to let the timer run. Hold 2 to discharge the spring without interfering with the timer.


I use a lever arm as well as a chain to store the energy. The lever arm with a spring applies constant tension to the gearbox ( enough to turn it ), while the chain expands under pressure to contain even more energy, letting the timer run much, much longer. The chain in this system would be similar to the spiral spring you see in most mechanical watches.

The second hand is driven by a simple escapement that oscillates at 60Hz, each cycle representing one second. The minute hand is then driven by a 60:1 gearbox off of the second hand driving gear.

*After working on it further, it appears that the gear ratio driving the minute hand is wrong, so it'll count minutes twice as fast as it should. Sorry about that.