A compact working LEGO Technic Clock with minute and hour hand using Mindstorms NXT.
Clocks are intriguing devices, with lots of gears which have to be very precise. Normally gears are specifically made, but when using LEGO parts there are only so many different gears to choose from. To make it accurate, but still small and compact was quite the challenge.
The clock exists of 2 main modules; the minute and hour hand module, and the compact housing with a total gearing reduction of 900:1, so if you turn the input 1 quarter per second, the output will make exactly 1 full rotation per hour.
Both the hour and minute hand share the same central axle.
The super compact gear box.