nickd
1591
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
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 f...
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 inv...
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
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....
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 s...
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...
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 pend...
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 On Oct 9, 2012 3:20 PM, "www watchprosite" *Alert from:* www:watchprosite > *Posted By:* elliot55 (registered) on October 9th, 2012 - 07:20 > > *Title: Much obli...