|Project by DickB||posted 02-20-2013 06:52 PM||2612 views||7 times favorited||10 comments|
This is the third wood-gear clock that I designed and built. I call this one the “Lazy Clock” because it ticks only once per minute. It uses an unusual, if not unique, mechanism – a solenoid-driven ratchet. The electrical coil is fired once a minute by a battery-powered microcontroller circuit, and that advances the minute hand. Because it ticks so infrequently, the gear train is much simpler than most clocks, making this one of the easiest wood-gear clocks to build.
My goal was to get this clock to run for a year on two AA cells. The solenoid had to be very low power, so there is a delicate balance between having enough power to reliably run the clock and conserve electricity. I used a rare earth magnet for the solenoid core to help achieve this. Well, I think I have achieved it – I’ll let you know in a year!
The back of the prototype is 3/4” mahogany and the face 3/4” hickory. The wheels (larger gears) are 1/4” Baltic birch. The pinions, hands, and other parts are 7/16” oak or maple. I built a second clock of all Baltic birch and maple.
I built the clock using a Carvewright CNC machine and designed it with that machine’s Designer software. Sorry, there is no way to export to other CNC formats. However, except for the carved face, the rest of the clock could be built with conventional tools such as a scroll saw and router. So, if anyone wants to design their own face and build one of these, I have extracted templates and published them on my we site here.
(If the link doesn’t work, copy and paste this: www.carveshop.com/html/lazy_plans.html )
If you do build one, I’d love to hear from you.
-- Dick, http://www.carveshop.com