Clock I - a fully functional clock, with hour, minute, and second hand. The gearing was fun to do, and the project is my first use of the rotation sensor: it keeps track of rotations allowing me to track time. In the only real test I gave it, it only lost about 5 minutes over a 4 hour span. Not quite NIST quality, but fun for the first try.
Here is the MLCAD file (11K).
A face shot showing the hands. Hour is on left, minute in middle, and second on right.
legOS source code. This code is not finished (for example, it makes the clock run backwards at the moment). If I get time I want to add functions to set the time, add an alarm clock, and make it play the standard clock tune every hour or half hour.
Perhaps if I get time I'll post a tutorial here on building this robot