5 ms·

The position of a watch influences accuracy (2020)

73 points by nequo 3y ago

mannykannot 3y ago
The article mentions, but does not describe, tourbillons, which are ingenious mechanisms to continuously rotate the escapement around one or more axes, so that the effects of orientation are averaged out. https://youtu.be/O-6KhwwM66k?si=W0-jQ033m_kkv7-R&t=200 https://youtu.be/O-6KhwwM66k?si=W0-jQ033m_kkv7-R&t=200
pard68 3y ago
My uncle always said you have to put your watch onto the rest/stand that comes with it as those are designed to hold the watch at the optimal position. I never understood what he meant since I've always worn a Casio F-91 for as long as I can remember.
- stevekemp 3y ago
  That's a little interesting, if only because a lot of watches don't come with stands/cases - I remember when I was a kid I got a couple of watches that had little plastic holders, that they were packaged with. These days I've got watches ranging from the low-end Casio Terrorist Watch to mid-range Rolexes, and a lot in between, and they typically come in boxes or cases without a stand of any kind.
deleted 3y ago
[deleted]
bvan 3y ago
Watch mechanics are fascinating. If only software was developed with such care and accuracy..
- bluescrn 3y ago
  People spend vast amounts on luxury mechanical watches, when a $10 digital watch does the job of timekeeping just as well, if not better. 'Luxury Software' hasn't become a thing (beyond ludicrously priced free-to-play whalebait)
  - eru 3y ago
    There's some really expensive software for CAD etc. And there's bespoke software, that can be almost arbitrarily ludicrous in terms of cost. I'm talking about eg corporate in-house software that has whole teams developing it, but only a few users. But I guess these examples are mostly just very expensive, but you don't use this software to brag to your mates.
  - Terretta 3y ago
    > 'Luxury Software' hasn't become a thing And yet, arguably, that's exactly what most app store subscriptions are, priced at several multiples of what that lightweight utility would have cost to purchase before the subscription model.
  - throw0101b 3y ago
    > 'Luxury Software' hasn't become a thing […] * https://en.wikipedia.org/wiki/I_Am_Rich https://en.wikipedia.org/wiki/I_Am_Rich
  - JohnBooty 3y ago
    Do you think that people buying mechanical watches are under the illusion that they're more accurate? Some people surely buy them for the status symbol aspect, and those are definitely the ones we notice because their watches are big and tacky. There are far more mechanical watches who don't wear brazen Rolex-esque "look at me" watches. You may not notice us because we're wearing Seikos, Citizens, Timexes, etc. Ironically the accuracy and ubiquity of mobile phone based timekeeping has made mechanical watches more practical. You don't need your wristwatch to be hyperaccurate if you're carrying a phone. when a $10 digital watch does the job of timekeeping just as well Surely not everything in your life is chosen strictly on terms of absolute performance? I'm sure you own some articles of clothing that were chosen despite the existence of cheaper alternatives that are functionally equivalent for your use cases.
Lio 3y ago
I wonder, how does orientation affect a watch with a Coaxial escapement? Since they're a relatively modern innovation I'd guess they were never really used in commercial applications like marine chronometers. https://en.wikipedia.org/wiki/Coaxial_escapement https://en.wikipedia.org/wiki/Coaxial_escapement
aredox 3y ago
Funny to see a fairly technical article on mechanical watches rank so high on HN. Yes, quartz watches are simpler and more accurate yadayada, but there is an interesting engineering challenge in trying to improve accuracy (1 second/day = 10 ppm!) through purely mechanical means. Constraints foster creativity.
- yodon 3y ago
  Long ago my dad (an experimental physicist) had a self-winding mechanical watch. At the end of the day, he would check if the watch had gained or lost time during the day (compared to the broadcast bell chimes radio stations used to broadcast on the hour). Based on the observation he would set the watch on its right side or left for the night, causing the spring in the self winding mechanism to be slightly more or less tensioned, leading to a slight gain or loss of time by morning to tune the watch to the precise broadcast signal.
  - hasoleju 3y ago
    Thanks for that story. While reading the article I always wondered what the value of the inaccuracy they where talking about really is. I guess it varies for different manufacturers. But seeing this shows me that even in the past it was only a matter of a few seconds.
  - bacheaul 3y ago
    Yes! On average, my Orient watch runs about 15-20s fast per week when I lay it flat on its back at night. But when I position it crown down at night, it runs about 4s slow per week. I usually check it every Sunday morning, and if it's running a bit slow, then I'll put it on it's back for a couple of night to let it catch up. Haven't had to pull the crown out and adjust it for about 2 months now with this system.
    - superhuzza 3y ago
      Haven't pulled the crown in 2 months? No daylight savings where you live? :)
- 3y ago
formerly_proven 3y ago
Orientation of a quartz watch also influences accuracy. Though a tuning fork watch crystal is probably not good enough to observe that.
- ricc 3y ago
  Maybe for analog and not digital? I believe temperature affects a quartz crystal more.
  - formerly_proven 3y ago
    > Typical crystal acceleration sensitivities will range from about 1 x 10-10 per g for specially constructed precision SC-cut and AT-cut resonators to the order of 10-7 per g for tuning fork resonators. https://www.microwavejournal.com/articles/print/7711-managing-crystal-oscillator-acceleration-sensitivity-in-mobile-applications https://www.microwavejournal.com/articles/print/7711-managin... Demonstration: https://www.youtube.com/watch?v=zILwgQhjC_Q#t=2m36s https://www.youtube.com/watch?v=zILwgQhjC_Q#t=2m36s
HPsquared 3y ago
Mechanical clock accuracy used to be pretty important for navigation to determine longitude. A large prize was offered by the British government to whoever could invent a way to accurately determine longitude. It's an interesting look at the high-tech world of yesteryear. https://watchesbysjx.com/2019/09/john-harrison-marine-chronometer-h4-diamond-pallets.html https://watchesbysjx.com/2019/09/john-harrison-marine-chrono... https://en.m.wikipedia.org/wiki/Longitude_rewards https://en.m.wikipedia.org/wiki/Longitude_rewards
- HPsquared 3y ago
  (Too late to edit) And, of course, clock accuracy is even more critical now in the age of GPS.
  - 15457345234 3y ago
    Technically yes but the user of that system doesn't have to have an accurate clock, the GPS system itself provides the time signal. I think the first stage of GPS positioning is clock signal acquisition and training the local oscillator. Once synced you can proceed with almanac download or whatever comes next. (The accurate (atomic) clocks are on the satellites and base stations.)
    - nequo 3y ago
      Seiko also builds watches that use GPS signals to set the time zone and the time.[1] Seems like a cool idea if you cross time zones often and have an extra $2,000 on your hands. [1] https://www.seikowatches.com/us-en/products/astron/features_gps https://www.seikowatches.com/us-en/products/astron/features_...
      - throw0101a 3y ago
        As does Citizen: * https://www.citizenwatch.com/ca/en/technology-satellite-timekeeping.html https://www.citizenwatch.com/ca/en/technology-satellite-time...
      - 3y ago

73 points by nequo 3y ago

The article mentions, but does not describe, tourbillons, which are ingenious mechanisms to continuously rotate the escapement around one or more axes, so that the effects of orientation are averaged out. https://youtu.be/O-6KhwwM66k?si=W0-jQ033m_kkv7-R&t=200 https://youtu.be/O-6KhwwM66k?si=W0-jQ033m_kkv7-R&t=200

pard68 3y ago

My uncle always said you have to put your watch onto the rest/stand that comes with it as those are designed to hold the watch at the optimal position. I never understood what he meant since I've always worn a Casio F-91 for as long as I can remember.

stevekemp 3y ago
That's a little interesting, if only because a lot of watches don't come with stands/cases - I remember when I was a kid I got a couple of watches that had little plastic holders, that they were packaged with. These days I've got watches ranging from the low-end Casio Terrorist Watch to mid-range Rolexes, and a lot in between, and they typically come in boxes or cases without a stand of any kind.

deleted 3y ago

[deleted]

bvan 3y ago

Watch mechanics are fascinating. If only software was developed with such care and accuracy..

bluescrn 3y ago
People spend vast amounts on luxury mechanical watches, when a $10 digital watch does the job of timekeeping just as well, if not better. 'Luxury Software' hasn't become a thing (beyond ludicrously priced free-to-play whalebait)
- eru 3y ago
  There's some really expensive software for CAD etc. And there's bespoke software, that can be almost arbitrarily ludicrous in terms of cost. I'm talking about eg corporate in-house software that has whole teams developing it, but only a few users. But I guess these examples are mostly just very expensive, but you don't use this software to brag to your mates.
- Terretta 3y ago
  > 'Luxury Software' hasn't become a thing And yet, arguably, that's exactly what most app store subscriptions are, priced at several multiples of what that lightweight utility would have cost to purchase before the subscription model.
- throw0101b 3y ago
  > 'Luxury Software' hasn't become a thing […] * https://en.wikipedia.org/wiki/I_Am_Rich https://en.wikipedia.org/wiki/I_Am_Rich
- JohnBooty 3y ago
  Do you think that people buying mechanical watches are under the illusion that they're more accurate? Some people surely buy them for the status symbol aspect, and those are definitely the ones we notice because their watches are big and tacky. There are far more mechanical watches who don't wear brazen Rolex-esque "look at me" watches. You may not notice us because we're wearing Seikos, Citizens, Timexes, etc. Ironically the accuracy and ubiquity of mobile phone based timekeeping has made mechanical watches more practical. You don't need your wristwatch to be hyperaccurate if you're carrying a phone. when a $10 digital watch does the job of timekeeping just as well Surely not everything in your life is chosen strictly on terms of absolute performance? I'm sure you own some articles of clothing that were chosen despite the existence of cheaper alternatives that are functionally equivalent for your use cases.

Lio 3y ago

I wonder, how does orientation affect a watch with a Coaxial escapement? Since they're a relatively modern innovation I'd guess they were never really used in commercial applications like marine chronometers. https://en.wikipedia.org/wiki/Coaxial_escapement https://en.wikipedia.org/wiki/Coaxial_escapement

aredox 3y ago

Funny to see a fairly technical article on mechanical watches rank so high on HN. Yes, quartz watches are simpler and more accurate yadayada, but there is an interesting engineering challenge in trying to improve accuracy (1 second/day = 10 ppm!) through purely mechanical means. Constraints foster creativity.

yodon 3y ago
Long ago my dad (an experimental physicist) had a self-winding mechanical watch. At the end of the day, he would check if the watch had gained or lost time during the day (compared to the broadcast bell chimes radio stations used to broadcast on the hour). Based on the observation he would set the watch on its right side or left for the night, causing the spring in the self winding mechanism to be slightly more or less tensioned, leading to a slight gain or loss of time by morning to tune the watch to the precise broadcast signal.
- hasoleju 3y ago
  Thanks for that story. While reading the article I always wondered what the value of the inaccuracy they where talking about really is. I guess it varies for different manufacturers. But seeing this shows me that even in the past it was only a matter of a few seconds.
- bacheaul 3y ago
  Yes! On average, my Orient watch runs about 15-20s fast per week when I lay it flat on its back at night. But when I position it crown down at night, it runs about 4s slow per week. I usually check it every Sunday morning, and if it's running a bit slow, then I'll put it on it's back for a couple of night to let it catch up. Haven't had to pull the crown out and adjust it for about 2 months now with this system.
  - superhuzza 3y ago
    Haven't pulled the crown in 2 months? No daylight savings where you live? :)
3y ago

formerly_proven 3y ago

Orientation of a quartz watch also influences accuracy. Though a tuning fork watch crystal is probably not good enough to observe that.

ricc 3y ago
Maybe for analog and not digital? I believe temperature affects a quartz crystal more.
- formerly_proven 3y ago
  > Typical crystal acceleration sensitivities will range from about 1 x 10-10 per g for specially constructed precision SC-cut and AT-cut resonators to the order of 10-7 per g for tuning fork resonators. https://www.microwavejournal.com/articles/print/7711-managing-crystal-oscillator-acceleration-sensitivity-in-mobile-applications https://www.microwavejournal.com/articles/print/7711-managin... Demonstration: https://www.youtube.com/watch?v=zILwgQhjC_Q#t=2m36s https://www.youtube.com/watch?v=zILwgQhjC_Q#t=2m36s

HPsquared 3y ago

Mechanical clock accuracy used to be pretty important for navigation to determine longitude. A large prize was offered by the British government to whoever could invent a way to accurately determine longitude. It's an interesting look at the high-tech world of yesteryear. https://watchesbysjx.com/2019/09/john-harrison-marine-chronometer-h4-diamond-pallets.html https://watchesbysjx.com/2019/09/john-harrison-marine-chrono... https://en.m.wikipedia.org/wiki/Longitude_rewards https://en.m.wikipedia.org/wiki/Longitude_rewards

HPsquared 3y ago
(Too late to edit) And, of course, clock accuracy is even more critical now in the age of GPS.
- 15457345234 3y ago
  Technically yes but the user of that system doesn't have to have an accurate clock, the GPS system itself provides the time signal. I think the first stage of GPS positioning is clock signal acquisition and training the local oscillator. Once synced you can proceed with almanac download or whatever comes next. (The accurate (atomic) clocks are on the satellites and base stations.)
  - nequo 3y ago
    Seiko also builds watches that use GPS signals to set the time zone and the time.[1] Seems like a cool idea if you cross time zones often and have an extra $2,000 on your hands. [1] https://www.seikowatches.com/us-en/products/astron/features_gps https://www.seikowatches.com/us-en/products/astron/features_...
    - throw0101a 3y ago
      As does Citizen: * https://www.citizenwatch.com/ca/en/technology-satellite-timekeeping.html https://www.citizenwatch.com/ca/en/technology-satellite-time...
    - 3y ago