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Project Information

Synchronicity is an exposed wood gear clock with a novel drive mechanism. Like one of my previous clocks, it uses an electromagnetic pendulum drive. A rare earth magnet is hidden in the back of the pendulum. As it swings past a coil hidden in the clock's back, a battery-powered circuit detects this and injects a pulse of current, repelling the magnet and giving the pendulum a push. A microcontroller measures each and every swing of the pendulum, and slightly speeds up or slows down the pendulum as needed, so the clock keeps perfect time.

I used Baltic Birch for the wheels (large gears) in previous clocks, but this time I wanted to give the gears more character, so I used 7/16" oak. Blanks were made up from eight pieces of oak wedges. I glued together four wedges at a time to make halves of the blanks, then sanded the sides of the blank halves to be glued to each other together. This corrected a slight error in the angle of the wedge cuts. The blanks were then raster carved to produce the hub and spokes, and the teeth vector cut.

The clock was entered and won a recent Carvewright contest. All of the parts were designed using the Carvewright Designer software and machined using the Carvewright CNC machine. Only a 1/16" ball nose carving bit, a 1/8" straight cutting bit, and a 60 degree V bit were used.

Most of the gears ride on brass bushings made of hobby brass tubing, but key parts such as the ratchet wheel and second hand shaft, and pendulum, are on bearings (like RC car bearings). A cam at the pendulum pivot is used to drive the moving pawl. This limits the travel of the pawl, regardless of the angle of swing of the pendulum, the latter of which is varied to regulate timekeeping.

The clock was designed to be a wall clock, but Carvewright intends for the contest-winning projects to travel to trade shows and the like. So I built a stand for it for more convenient display. I also built a shipping box to ensure the clock could travel safely. And I made a video for the contest, to highlight features of the clock and illustrate some of the design and build process:



A variety of woods were used: mahogany back, oak wheels and pawls, maple frame and pinions, pine face and pendulum, hickory bob and stand, and walnut hands. No stains were used, just three coats of satin lacquer, the final coat out of a spray can.

I have a few tweaks to make to the design to make the clock a bit easier to build. Once I do that, I intend to put the design into the Carvewright Pattern Depot for others to build. (Sorry, Carveright files use a proprietary format, so it is not possible for me to convert to DXF for other machines.)

Gallery

Comments

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19,753 Posts
Very cool a wonderful and unique.
 

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345 Posts
Incredible! Wish I could tell you I understood half of your posting but this would be a falsehood… Amazing work without a doubt… Thanks for sharing…
 

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841 Posts
Very nicely done!
 

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This has to be much fun to watch it operate!
 

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326 Posts
nice work. Where did you find the circuit that imparts the pulse? I have designed my own circuit but, I find that mine is an energy hog and will not survive several months of battery power without a change. The gears will be an issue as soon as you cross weather boundaries during your travel. I have some experience here! I'd be willing to share my own experiences with you. Your call. Well done!
 

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247 Posts
Hello Dick

Congratulations for the piece and the patience

A fantastic work

I love all these types of clocks (a project like this in the future for me perhaps !!!)

Thanks for sharing
 

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Thanks all!

HorizontalMike, you can see it run in the video.

Max, your clocks are amazing! I design and build my own electronics. This clock is not as efficient as I would like. I think it will do better with a stronger magnet and a double coil. That is one of the tweaks I plan to try.
 

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This is truly a work of art! Jaw dropping gorgeous.
 

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This is an awesome clock I love it.
 

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It's hard to say something clever. It's so amaizing that I'm speachless.
 

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186 Posts
Way cool!!! Very intense design, I dig it, and I love clocks…
 

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421 Posts
I like the design. Very nicely done. I like solid wood gears much more than Baltic birch.
 
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