28 Feb '16, 6am

This Hourglass Flips Itself

This Hourglass Flips Itself

Once upon a time, [Mike] bought an hourglass for his sister. He intended to build it into a clock and give it to her as a gift, but life and other projects got in the way. Fast forward a couple of decades to the point when it all came together and [Mike] had everything he needed on hand to build a beautiful wooden clock that automatically flips the hourglass over . Every 60 minutes, the bulb, which is situated inside a handcrafted maple ring, rotates 180 degrees to restart the flow of sand. Whatever number is at the top of the outer wheel denotes the current hour. The digit for the next hour is always at the five o’clock position relative to the current hour. This works out because the pockets on the outside of the bulb’s ring share a 5:6 ratio with the gear teeth on the outer ring. Confused? Watch the time-lapse video from [Mike]’s that shows it in action. [Mike] was dete...

Full article: http://hackaday.com/2016/02/27/this-hourglass-flips-itself/

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