DonCorson
[AHCI]
3358
An answer to one...
An answer to one... maybe.
The picture looks to me to be the mechanism for the equation of time. I read it like this: The big toothed wheel turns once a day. The lever that is at the right will be actioned by a pin on the movement with each rotation advancing the ratchet gear with the very fine teeth, 365 of them. On the back of the ratchet gear where we can't see it is the equation of time cam which drives the followers above and below that then turn the cannon on the axle. The EOT hand is planted on the cannon. The cannon thus turns with the hour hand, but has an added movement that changed once a day showing the difference between average time and solar time.
I would expect that quartz glass has a particularly low thermal expansion coefficient, but will ask David to take a look and give us some definative answers.
Don
David Walter's Double Pendulum Clock
David Walter has completed his Double Pendulum Clock You may have seen these pictures elsewhere before. They are worth taking a look at again. A text with lots of explanation by David is after the pictures. HISTORY The first time I saw a photo of Breguet ...
Thanks a lot Don for the post.
An outstanding clock ! I had the chance to see another Double Pendulum clock one year ago: it was a project coming from Jean-Baptiste Viot: Fr.Xavier...
Thanks Don for the wonderful post...
of a great master clockmaker and his masterpiece that I truly admire! A fantastic read. Very highly appreciated.
Is it where FP Journe got his idea from ?
Thanks Don. Beautiful and huge clock. Regards Ling
Maybe not directly...
but since Janvier and Breguet resonance has been in the air waiting to be put to work again. I don't really understand why David calls the clock a double pendulum clock and not a resonance clock. There are many double pendulum clocks that are not resonant...
Don, I agree with you.
I have the same doubt as mentioned by you after I double checked the mechanism with my engineer friend. He actually laughed at me and said that common sense would tell me that it didn't work that way. Regards Ling
Double Pendulum Resonance Clock
Hi Don, Daniels Describes Breguet 3671 in The Art of Breguet, as a "Double Clock", initially I used the name of Double Pendulum Resonance Clock as I believe this describes it better, however this is also a mouthful of words in a name so I adopted the name...
I too have heard about the "reality" of the FPJ Resonance watch
It comes from a very qualified, genius watchmaker, who worked with FPJ at one time in and who decided to test it in a vacuum one day! Not surprisingly to him he said, the two balance wheels very quickly started to oscillate at irregular speeds to each oth...
If I understand you correctly...
If I understand correctly that would actually mean that there is some weak transfer of energy in the FPJ watch. As the air in the watch is the probably the biggest vector of enegy transfer, taking away the air would remove that transfer. So if the balance...
Yep that about sums it up, the "air" makes it possible...
Hi Don, I was fascinated to hear this myself, not having the technical training, but hearing it from this watchmaker and how he described his experiment to verify it, was eye opening and not something I would have even thought about if he had not brought ...
This is not a clock…
… it is so much more than that. It is a work of art; a high-point of craftsmanship which also conveniently happens to tell the time – and then some! There is much to be appreciated in David’s ‘magnum opus’ ; paradoxically, as much for what is not there, a...
Beautifully said pplater.
And thank you Don for posting this. I must admit, as a 'watch person', I had not really considered the plight of the clockmaker post the quartz era, but as you say, it must be a difficult thing to keep alive these skills and craft in an age like this. Wha...
And here a picture of the wall mounted version...
David Walter's Double Pendulum Resonance Clock, wall mounted...
Three questions...
First of all, thanks for the fantastic report! I have a few questions, all on details of the movement: 1. What is this thing? It looks like it might be part of the winding mechanism? 2. You talk about how the dials are "French Silvered" which has a differ...
An answer to one...
An answer to one... maybe. The picture looks to me to be the mechanism for the equation of time. I read it like this: The big toothed wheel turns once a day. The lever that is at the right will be actioned by a pin on the movement with each rotation advan...
Some ideas...
As Don says, quartz for the pendulum rod becaue of the very low coefficinet of thermal expansion. It also doesn't suffer from the stability problems of Invar. On the other hand, it brings it's own "challenges" that David can no doubt explain. nick
Answers
1;The wheel in question is indeed the Equation of Time wheel as Don correctly surmised. This wheel turns once per hour, the blued steel mean time minute hand is fitted to the square while the gold Equation of Time hand is fitted to the steel pinion which ...
Simply a gorgeous piece of art!
Thanks, Don, for highlighting this lovely clock, which is frankly more than a clock, it's a beautiful work of art and engineering. We rarely talk about clocks, but they are worthwhile objects to discuss. Congratulations to David Walter. Cheers, Daos