Mystery Clock

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Project by DickB posted 951 days ago 4220 views 24 times favorited 15 comments Add to Favorites Watch

This is an exposed wood gear clock project that I am working on. All of the moving parts are out in the open, so you can see everything working, but what makes it tick is a bit of a mystery to many. Unlike most pendulum clocks where the pendulum regulates the movement, in this clock the pendulum drives the movement.

The pendulum contains a rare earth magnet, and the base has a coil of wire in it. As the magnet passes the coil, an electronic circuit senses the magnet and sends a current pulse into the coil. This gives the pendulum a “kick” and keeps it moving.

Others have designed and built clocks like this, but I have developed what I believe to be a unique drive circuit. I use a microcontroller with a watch crystal reference, and compare pendulum period to the crystal reference. Then, I adjust the pulse to the coil to speed up or slow down the pendulum a bit. This makes the clock much more accurate than it otherwise would be. There is also an LED in the base that flashes red or green if the pendulum is too fast or to slow. This makes it easier and quicker to set the pendulum bob.

I’m fine-tuning the design with three clocks built and running at this time.

Here’s a video:

-- Dick,

15 comments so far

View Charles Maxwell's profile

Charles Maxwell

951 posts in 2440 days

#1 posted 951 days ago

Very nice! I’ve built a few clocks as well. I have only done one with a electro-mechanical impulse drive. I use a few transistors to time and impulse the neodymium magnets at the end of the pendulum. I’d be interested in comparing designs. I’m curious as to the battery life of your clock design.

-- Max the "night janitor" at

View DickB's profile


61 posts in 952 days

#2 posted 951 days ago


You have some very beautiful clocks!

Calculated battery life is over a year on 4 D cells. This is my first pendulum clock, and I’ve not had one running long enough to verify. I have had one running for about a month. I was thinking of running one to exhaustion on AAA cells to verify.

-- Dick,

View a1Jim's profile


112015 posts in 2210 days

#3 posted 951 days ago

Hi Dick
Welcome to Ljs
That’s one fantastic clock

-- Custom furniture

View tom427cid's profile


294 posts in 1103 days

#4 posted 951 days ago


-- "certified sawdust maker"

View StumpyNubs's profile


6173 posts in 1433 days

#5 posted 951 days ago


Thanks for posting!
-Jim; aka “Stumpy Nubs”
(The best woodworking show since the invention of wood.)

-- It's the best woodworking show since the invention of wood... New episodes at:

View KYJeepGuy's profile


40 posts in 1074 days

#6 posted 951 days ago

Nice job, beautiful work. Which CNC router/engraver do you use?

-- If I'm not in the shop, I'm someplace else. Joel, Lumberjock #30,000

View DickB's profile


61 posts in 952 days

#7 posted 951 days ago

Thanks. CarveWright. Reasonably priced, no extra charge for the basic but very capable software, easiest to use of the software packages that I sampled. Some people have a lot of trouble with the machines, but much can be avoided by using a good dust collection system (which oddly the manufacturer does not provide) and paying attention to maintenance needs.

-- Dick,

View majuvla's profile (online now)


3324 posts in 1500 days

#8 posted 951 days ago

Awsome.Very good looking

-- Ivan, Croatia, Wooddicted

View Manitario's profile (online now)


2303 posts in 1515 days

#9 posted 951 days ago

Beautiful clock, very unique motion! Welcome to LJ’s.

-- Sometimes the creative process requires foul language. -- Charles Neil

View Diggerjacks's profile


1744 posts in 1771 days

#10 posted 951 days ago


Welcome to LJ’s

This type of project is for me the best of the best for the scroll saw working

I love it

Thanks really for sharing

-- Diggerjack-France ---The only limit is the limit of the mind and the mind has no limit

View bobasaurus's profile


1233 posts in 1817 days

#11 posted 951 days ago

Very clever clock mechanism. I want to make one badly.

-- Allen, Colorado

View rhettbarker's profile


6 posts in 992 days

#12 posted 950 days ago

that is awesome you should publish some plans. I have a carvewright and would like to build that.

View DickB's profile


61 posts in 952 days

#13 posted 950 days ago


I’m working on getting this into the CarveWright PatternDepot as a project, and also offering a kit of hardware parts including built and tested electronics. Hope to have it ready soon.

I have another clock in the depot already:

-- Dick,

View CaptainSkully's profile


1190 posts in 2191 days

#14 posted 949 days ago

I’m very interested in getting one. Please post when they become available. Thanks.

-- You can't control the wind, but you can trim your sails

View Dennis Zongker's profile

Dennis Zongker

2419 posts in 2225 days

#15 posted 948 days ago

Great Looking Clock!!! Welcome to Lumberjocks.

-- Dennis Zongker

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