Comments:
to perturbations, both of which CAN aid accuracy, both actual and perceived, but don't guarantee it.
some would argue that the soothing sonic beat qualities of a low beat escapement offset any advantages of possible better accuracy of the high beat.
I invite you to visit the subject in our tech forum for a more technical treatment of the subject.
Cheers,
TM
Not sure how many bph or hz that is, but when i had it running it sounded very relaxing and only beaten by my grandfather clock that ticks every second.
I like the sound of an 18000 bph watch, but as we dont hold them to our ear all day i dont mind what speed my watches run at.
Interesting thread Scott.
G
7,200vph = 1Hz / 18,000vph = 2.5Hz / etc...
It is truly amazing that something so small and delicate can oscillate hundreds, if not thousands of times per hour.
A vast majority of mechanical watches run at 28,800vph, or what is referred to as 4Hz. This means that the palette fork will go back and forth 4 times (for a total of eight touches) every second. And so, if you were to look closely at the "sweeping" seconds hand on say, your Rolex, you'd see that it is really making 8 small movements per second. If you are the lucky owner of a JLC Duometre, you have a watch that runs at 3Hz, or 21,600vph. In this case, the palette fork goes back and forth 3 times for a total of six (6) touches every second. Hence the 1/6th of a second foudroyante hand at six o'clock. Many chronographs, for example, have ultra fast heartbeats in excess of 5Hz (36,000vph) in order to track and show 100th's of a second. Obviously, the challenge with watches that run at a high Hz is incorporating materials and parts that will not wear down due to the higher stress levels within the mechanics.
Personally, I have always been fascinated by the variances in watch oscillations, and have always wondered what the watchmaker is thinking when he/she decides the heartbeat's pace. My brother has a Panerai PAM 177, with an ETA 6497 that runs at 2.5Hz, or 18,000vph. I suppose the slower the regulator, the more difficult it is to adjust. One thing's for sure - when my brother's Panerai is running properly it keeps particularly excellent time. Truth be told, my Habring2 Foudroyante (4Hz) is ridiculously accurate and watching the 1/8 of second hand fly around (and trigger the dead-beat seconds hand) is practically hypnotic. Of all my watches - Casio G-Shock not withstanding - it is my Chinese-made tourbillon that keeps time the best. Oscillating at 21,600vph, its accuracy is truly outstanding. Unfortunately, the Panerai-like design is quite uninspired and the watch spends most of its time in the box.
Since tracking the speed of a regulator is relatively new ground for me, I invite any and all input regarding this post. And I apologize in advance if some of the information I have put forth is not entirely accurate. Although I have done research on this topic, there does not seem to be a whole lot of definitive resources on the web. I look forward to learning more about these all these mathematical equations.
- Scott
in the most basic terms, higher frequency = greater resolution and more resistence
to perturbations, both of which CAN aid accuracy, both actual and perceived, but don't guarantee it.
some would argue that the soothing sonic beat qualities of a low beat escapement offset any advantages of possible better accuracy of the high beat.
I invite you to visit the subject in our tech forum for a more technical treatment of the subject.
Cheers,
TM
Brilliant!
Thanks so much for the feedback. I am eager to learn more about how and why watchmakers choose the frequency to utilize in their watch. Much appreciated.
- Scott
- Scott
I think it's as much about what can be done as what should be done.
For a long time, the 2.5 hz standard (18,000 vph) was state of the art. My guess is that below that rate there's a real drop-off in precision; I have never seen a watch, even a really old one, that used a slower rate.
The first move was a small one, to 2.75hz (19,800 vph). That must have made a lot of difference, as the heavyweights went with it: for example, it was included in Rolex's transition from caliber 1560 to caliber 1570; Patek's from caliber 12-600 to 27-460; IWC's caliber 85 to 852; etc. Presumably the manufacturers would have liked to go farther, say to 21,600 vph, but I think the required mainspring strength, manufacturing precision and lubricants were hard to come by. Thus, there aren't as many 21,600 vph movements around as one might expect.
Then there must have been some technological breakthroughs because suddenly everyone was manufacturing movements at 28,800 vph. (Not everyone; some companies really had a tough time getting over that hurdle and stayed behind for years or even decades.) I think this made a huge difference in watch performance in the low and middle ranges, although perhaps less at the top end. (It's interesting that some of the top brands were relatively slow to move to 28,800 vph. A really well-made 19,800 vph movement, with Breguet hairspring and variable inertia balance, is still quite competitive with a freshly- serviced high-beat movement and may gain an advantage a couple of years after servicing as it is less reliant on optimum lubrication conditions. In my limited experience, however, no 18,000 vph movement is in the same league.)
The next question would be why only a few companies moved on to 36,000 vph. As the owner of a couple of those contraptions, I think it's fair to say that the maintenance issues exceeded the timekeeping benefit. It's also interesting that Omega, for its coaxial escapements, scaled back from 28,800 to 25,200 vph. It's really quite a fine balancing act.
Generally, in movement design a faster beat correlates with a smaller balance. Since larger balances on the whole perform better than smaller ones, there are always tradeoffs.
In addition to purely mechanical issues, there is the question of how a movement's beat correlates with normal human activities. It's a bad thing to have the watch's natural rhythm tend to synchronize with the wearer's natural rhythm, as there will be a tendency for errors to be reinforced.
Leaving aside pure timekeeping performance, I do enjoy the look and sound of slower-beat movements.
The first move was a small one, to 2.75hz (19,800 vph). That must have made a lot of difference, as the heavyweights went with it: for example, it was included in Rolex's transition from caliber 1560 to caliber 1570; Patek's from caliber 12-600 to 27-460; IWC's caliber 85 to 852; etc. Presumably the manufacturers would have liked to go farther, say to 21,600 vph, but I think the required mainspring strength, manufacturing precision and lubricants were hard to come by. Thus, there aren't as many 21,600 vph movements around as one might expect.
Then there must have been some technological breakthroughs because suddenly everyone was manufacturing movements at 28,800 vph. (Not everyone; some companies really had a tough time getting over that hurdle and stayed behind for years or even decades.) I think this made a huge difference in watch performance in the low and middle ranges, although perhaps less at the top end. (It's interesting that some of the top brands were relatively slow to move to 28,800 vph. A really well-made 19,800 vph movement, with Breguet hairspring and variable inertia balance, is still quite competitive with a freshly- serviced high-beat movement and may gain an advantage a couple of years after servicing as it is less reliant on optimum lubrication conditions. In my limited experience, however, no 18,000 vph movement is in the same league.)
The next question would be why only a few companies moved on to 36,000 vph. As the owner of a couple of those contraptions, I think it's fair to say that the maintenance issues exceeded the timekeeping benefit. It's also interesting that Omega, for its coaxial escapements, scaled back from 28,800 to 25,200 vph. It's really quite a fine balancing act.
Generally, in movement design a faster beat correlates with a smaller balance. Since larger balances on the whole perform better than smaller ones, there are always tradeoffs.
In addition to purely mechanical issues, there is the question of how a movement's beat correlates with normal human activities. It's a bad thing to have the watch's natural rhythm tend to synchronize with the wearer's natural rhythm, as there will be a tendency for errors to be reinforced.
Leaving aside pure timekeeping performance, I do enjoy the look and sound of slower-beat movements.
Awesome Insight
MKVC -
Thanks so much. Your informative post (which I've now read three times) only makes me want to delve that much deeper!
- Scott
i had a Lange & Sohne marine chronometer from 1943 that ticked twice per minute
Not sure how many bph or hz that is, but when i had it running it sounded very relaxing and only beaten by my grandfather clock that ticks every second.
I like the sound of an 18000 bph watch, but as we dont hold them to our ear all day i dont mind what speed my watches run at.
Interesting thread Scott.
G
My Atmos Clock
Hey, G -
I think my ATMOS runs modestly, with the regulator making a full sweep every thirty seconds. So is this 1Hz? Are clock escapements measured the same way? I tried to pose this question to Martin Braun the other night and he just looked at me as if he didn't know enough English to explain it to me. Fact of the matter is, there are so many factors that go into the Hertz that the watch (or clock) runs at it'll make your head spin around at thousands of vibrations per hour... so to speak.
End of the day, I gathered it was more of an organic approach for Martin where he focuses in on 2.5Hz, or 18,000vph.
- Scott
I forgot my atmos. A...
I forgot my atmos. A beautiful slow rotation that mesmerises you, especially with a mirror behind it.
G
Confusion from clocks :)
Clock pendulums were traditionally referred to in terms of the time to make one half-swing (eg from left to right), probably because most of the escapements acted on both the L->R and R->L swings and you design the wheel train to count the "ticks".
A pendulum with a half-swing of one second and a classic escapement ticks every second, which is very convenient for all sorts of mechanical design aspects and has the advantage that a one second pendulum is roughly a meter long and so a good size for a long case clock. This is a very convenient length as the dial can be centered on the average eye height of about 1.6 m (one of those design considerations which is totally obvious once you know about it 
), you've got a good drop for the weights so you can go for a long running time without rewinding, and you can increase the mass of the pendulum bob (eg 7 kg in a Synchronome, Pulsynetic) which is great for long term accuracy and stability.
), you've got a good drop for the weights so you can go for a long running time without rewinding, and you can increase the mass of the pendulum bob (eg 7 kg in a Synchronome, Pulsynetic) which is great for long term accuracy and stability.A so-called "one second pendulum" makes a full oscillation (left to right to left) in two seconds, which means a period of 2 seconds and as f=1/T the frequency is 0.5 Hz.
3/4 second pendulums were also common as this gives an easy count for the wheel train and a case about a meter high for the pendulum of about 60 cm, just right as a wall clock. 1/2 second pendulums have a frequency of 1 Hz and a length of about 25 cm.
Alex
AtmosI
I just looked up Atmos.
2 oscillations per minute=1 oscillation in 30s (the period). f=1/T the frequency is 1/30s=0.033 Hz.
Alex
Much obliged...
Nick -
Thank you for your post! Great explanation. Clears up many questions.
Now I can't stop staring at my Atmos!
- Scott
Yes, i must say a ...
Yes, i must say a big thank you as well Nick. Clocks will never appear the same again.
Best
G