A Harmonic Oscillator Clock

[John TenEyck]

I just finshed building this clock, designed by Clayton Boyer, for a friend. Actually, he built the base and I built the clock works and dial. This clock uses a harmonic oscillator to release the escape wheel, in contrast to a more typical pendulum clock.





The base is Sapele, the clock frame is unfinished mahogany, the dial ring is paduak with ebony inlays, and the wheels (gears) are unfinished maple and paduak shop-made plywood. The gear train is pretty simple, but the mechanism to control the escape wheel was difficult to understand until I had it mostly assembled and just as difficult to adjust so that it would run smoothly. The drive weight is four copper tubes filled with lead shot. The oscillator is made from hollow copper spheres also partially filled with lead shot.

Unlike a pendulum clock, this clock only goes tick or tock, once every 30 seconds, so it's pretty quiet. The oscillator releases the escape wheel when it winds the spring it's hung by far enough for the lever connected to the spring to push or pull the escapement mechanism far enough for one of the two pallets to pull away from the escape wheel. Sounds complicated, right? It's not, but it is a lot more complicated than a typical pendulum mechanism. Here's a short video to show how it works.

https://photos.app.goo.gl/1QAoA7xnvahD8b4W7

John

[Ted Calver]

Very cool!...and beautiful work!

[Ken Fitzgerald]

I agree with Ted! Beautiful piece and excellent work! Well done, Sir!

[Mel Fulks]

Interesting and certainly well done. But, when you have gatherings you need a sign for it… “ Not A Weight Scale!”

[John TenEyck]

Interesting and certainly well done. But, when you have gatherings you need a sign for it… “ Not A Weight Scale!”

My friend and I jokingly talked about putting brass posts with braided red rope around it, like you see at galleries, to keep people away from it. When kids show up, he may need a wire fence. If dogs enter the picture, it's toast.

John

[Mel Fulks]

I’ve again been reading SUNDIALS AND ROSES Of LONG AGO . Lots of B&W pics of some
beautiful and complicated dials. Many are carved stone ,and big. About 1910

[Mark Rainey]

I am not sure what to make of the contraption John...most importantly does it keep time?

[Keith Outten]

WOW, absolutely stunning!

[John TenEyck]

I am not sure what to make of the contraption John...most importantly does it keep time?

Hi Mark. Harmonic oscillator clocks aren't all that common, although you might have seen one inside a glass dome once upon a time. Those often were called "Anniversary" clocks. The video shows that it actually does run. In fact, it runs very smoothly and doesn't make much noise since it only ticks or tocks once every 30 seconds. But you don't make any wood gear clock to have a great time keeping piece, and harmonic oscillators keep time less well than pendulum clocks, for example. I had it to about 1 minute/day in my shop, which has pretty constant temperature and humidity, but I doubt it will do that well in its new spot in my friend's house, where ambient conditions vary a lot more. But time will tell .....

John

[Jim Becker]

Stunning...is an understatement. Wow. Not only amazing workmanship, but Holy Complicated, Batman!

[Mark Rainey]

Thanks John. John Harrison and I will be interested in knowing how it does over time.

[David Falkner]

Very cool, and good looking, as well - great job!

[John TenEyck]

Thanks John. John Harrison and I will be interested in knowing how it does over time.

You know the harmonic oscillator, also called the torsion pendulum, was invented by an American in 1841, long after Harrison's time. Harrison probably would have thought the mechanism to be pretty crude.

John

[Edward Weber]

Nice job on the grain following around the dial

[John TenEyck]

Nice job on the grain following around the dial

Thanks Ed. I cut those segments on the CNC, only to find out the edges weren't square which led to a lot of effort to make them so to avoid ugly joints after glue-up. Most, but not all, are pretty good. I had no more paduak so I had to make do. The only good news from it all is that I learned some more things about what does and does not give a square edge when milling on the CNC. Classic woodworking with a table saw, etc, is, in many ways, a simpler and more straight forward process.

John