Home » Gruen Box Database » 1920s » Long service box
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| Re: Long service box [message #14861 is a reply to message #14860] |
Thu, 13 May 2021 19:54   |
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Jenneke
Messages: 1904
Registered: May 2013
Location: Netherlands
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Gruen Authority |
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I had never seen this type of box before, must be rare. The width of the slot clearly reflects the period.
The square box and the longer one are still on my wishlist. 
In the care instruction to things strike me:
- preferably wind your watch in the morning: why?
- a small watch will give its own warning and stop: are they saying it is no problem to wait until your baguette/cartouche stops?
You can only waste time if you forget to enjoy it - Loesje
[Updated on: Thu, 13 May 2021 20:16] Report message to a moderator |
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| Re: Long service box [message #14864 is a reply to message #14861] |
Thu, 13 May 2021 22:49 |
thesnark17
Messages: 654
Registered: January 2017
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Gruen Master |
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Wind your watch in the morning:
Watches keep their best time at their highest amplitude, because the balance behaves most like a "free spring" (which is a theoretically perfect timekeeper) when at its highest possible amplitude. Watches have lower amplitude on average across all positions when being worn (compared to when sitting on a timing machine) due to the effects of body movement on the (gyroscopic) balance. Winding the watch in the morning allows the overall amplitude to be higher during the day then it would be if wound at night, which means that the watch keeps better time on the wrist. Of course, you could wind your watch back up regularly through the day for even better results, but most people wouldn't do something like that -- unless they're wearing an automatic watch!
(One of the goals behind the development of the automatic watch was to maintain the highest possible amplitude throughout the day, thus improving timekeeping. The other was to get a more constant mainspring force, which also improves timekeeping, largely because the balance amplitude follows the mainspring force linearly. Rewinding a manual watch every hour of the day checks both boxes nicely but is not automatic.)
A watch's timekeeping is consistent over the course of a wind. For instance, sitting on a table, the watch may begin by gaining a second over a few hours, then run perfectly on time for a few hours, then run several seconds slow; and so on, as the mainspring runs down. And, if you left it on the table every day, it would do the same thing every day (assuming temperature and orientation are constant). If rewound at the same time every day, such a watch could be used to find the time extremely reliably (probably to the second over several months, though it might be off by several minutes over that time-frame), due to the known and consistent errors in its timekeeping. This is the principle behind marine chronometers. However, if rewound at irregular intervals (perhaps after 30 hours on one day, and 16 hours the next, only to be wound again 4 hours later), the timekeeping will be more erratic and not predictable. Much more erratic, if the watch is run far past 24 hours since a winding (for watches that are designed with 30-36 hour mainsprings. Watches with longer mainsprings will be more resilient. This is one of the reasons why the best American railroad watches carried 48+ hour mainsprings, even though they were intended to be wound once a day.) All this to say that the watch will keep better time, if wound at the same time every day.
And finally, there are only two times of day at which a regular person would think to wind a watch: when they are putting it on, and when they are taking it off. Given that higher amplitude is more important in the day when the watch is being worn, it makes sense to advise the user to make a habit of winding the watch in the morning, when they are putting it on.
[Updated on: Thu, 13 May 2021 22:52] Report message to a moderator |
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| Re: Long service box [message #14865 is a reply to message #14864] |
Thu, 13 May 2021 23:20 |
thesnark17
Messages: 654
Registered: January 2017
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Gruen Master |
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Small watch gives its own warning:
All wrist watches have relatively comparable amounts of friction on the train when clean. The mainspring is designed to deliver a reasonable amount of energy to overcome this load on the train (which includes pivot friction, the balance action, and dirt as it accumulates). The mainspring can only be a certain size to fit into the movement, so there is an upper limit on how much power it can provide. For wrist watches, it isn't much.
As dirt gets into the movement, the friction will increase. As it does, the amount of mainspring power delivered to the balance will decrease, causing the balance amplitude to decrease (remember, power and amplitude are linearly related). This will result in the watch keeping more erratic time due to low amplitude. Once the train is inhibited enough, the watch will stop before reaching the 24 hour rewind point. Since the mainspring did not have much force to begin with, you will find this effect quite noticeable once it begins.
This is particularly noticeable if the friction increases because the oil gums up. Whale oil was used from c.1840 to c.1960 for watches, and it has some interesting properties. First, it is more "oily" and far more effective at preventing pressure-based wear, compared to modern synthetic oils. Second, it does not significantly alter its properties over its working lifespan - it is stable (and highly protective against wear) as long as it is liquid. Third, as it ages out, it becomes "gummy". This rapidly increases the friction on the train and is sufficient to stop a small watch movement all by itself.
So, if you are following Gruen's advice, and using whale oil in your watch:
- If the watch gets dirty, it will stop or run irregularly, and you will know it needs service. If at that point, you get it serviced, it will not have run long with dirt in it and there will be no damage.
- If the watch lubricants begin to age out, the watch will stop or run irregularly, and you will know it needs service. &c no damage.
- If the watch is running without issue, you know that neither of the above cases is true, and you can be confident that your watch is still clean and that the oil is protecting against wear.
The problem comes when you don't use whale oil! (which of course has not been available for more than 50 years, since you have to kill whales to get it - don't use it!) Modern lubricants don't behave the way whale oil does, and it's quite possible to run a wristwatch past the point where the lubricants are protecting against wear, without noticing a change in timekeeping. So Gruen's rules don't work any more.
Also, as Gruen themselves point out, pocket watches have much higher power in their mainsprings, so can push through dirt buildup and oil breakdown - possibly so well that the user would not immediately notice the degradation in the timekeeping that would result (this is aided as well by the fact that a pocket watch doesn't move around as much - nor is it usually in so many positions - as a wristwatch, over the course of a day). And after the point where the lubricants stop working, the pocket watch just keeps grinding itself to death until the user notices the drop in performance, by which time it is far too late to do anything about it without extensive work (and maybe not even then). Thus the warning.
[Updated on: Sun, 16 May 2021 23:23] Report message to a moderator |
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| Re: Long service box [message #14880 is a reply to message #14879] |
Sun, 16 May 2021 23:27 |
thesnark17
Messages: 654
Registered: January 2017
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Gruen Master |
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Oh, I'm sure we all grind watches at least a bit. I know I don't service all of mine - but I do service the ones I wear regularly. It would take a fairly long time to do serious damage. Of course, it is cumulative damage...
I actually like it when a seller says that the watch doesn't run and the works seem gummy. That usually means it's still got whale oil in it, which in turn means that it hasn't run since the '50s or earlier.
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not a regular person. Most of the times I think of it is a few seconds after I put it on my wrist. Too late. 
that is just.. a nono. But very interesting to know. So smelly non running watches contain old animal oil. 
