Can accuracy be affected by time on the wrist between full winding?

[burnthesehills]

Let’s say for example I wear a Sub for several weeks or even months on end without winding it. Granted it is being automatically wound while worn by the rotor. But depending on activity level and time on the wrist (versus in a drawer) I assume the mainspring will eventually wind down to some degree. Could this affect accuracy in terms of the watch losing more time? Conversely, would letting the watch completely wind down and giving it a full wind with a fresh start so to speak be better for accuracy?

Or is there basically no relation?

[Jerrocop]

Always seems like my watches are more accurate when I’m wearing them. I generally wear my all day and sleep with them. They seem to regulate better but maybe that’s because I have a good vibe?


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[Rolex1982]

Originally Posted by burnthesehills

Let’s say for example I wear a Sub for several weeks or even months on end without winding it. Granted it is being automatically wound while worn by the rotor. But depending on activity level and time on the wrist (versus in a drawer) I assume the mainspring will eventually wind down to some degree. Could this affect accuracy in terms of the watch losing more time? Conversely, would letting the watch completely wind down and giving it a full wind with a fresh start so to speak be better for accuracy?

Or is there basically no relation?

There is a small relation between activity level and accuracy. If your not active, after a few days the power reserve is empty and it will stop. I cannot imagine that the accuracy will change over the course of the days. But that’s not based on any technical knowledge but only on my own experience. N = 1.

[burnthesehills]

Originally Posted by Rolex1982

There is a small relation between activity level and accuracy. If your not active, after a few days the power reserve is empty and it will stop. I cannot imagine that the accuracy will change over the course of the days. But that’s not based on any technical knowledge but only on my own experience. N = 1.

I am active enough and wear the watch frequently enough where it never winds down completely. Having said this, some days it does not get worn and others just for desk diving, etc. So while it has not wound down completely I assume the power reserve is on the low side. But again not sure if this would affect accuracy or how.

[Tim Plains]

Should be less accurate as the main spring unwinds. It's not like a rechargeable battery that should be depleted every once in a while and fully charged.

[Tools]

Originally Posted by burnthesehills

I am active enough and wear the watch frequently enough where it never winds down completely. Having said this, some days it does not get worn and others just for desk diving, etc. So while it has not wound down completely I assume the power reserve is on the low side. But again not sure if this would affect accuracy or how.

Everything affects "accuracy", in that temperature, gravity, mainspring wind, etc., all determine how far apart the ticks are in each second.

Yes, you should let the mainspring completely unwind from time-to-time. Springs need to overcome their own friction when unwinding, so the inner, more tightly wound, layers are more compressed (more friction). Letting everything relax before re-winding can release some of this inherent torque-lock in an always tightly wound coil.

[Calatrava r]

Most watches are designed to run the same over most of the state of the wind. It should run the same fully wound or just about run down, otherwise watches would be pretty worthless for time keeping. It is quite amazing actually the escapement runs the same over the length of the wind. Letting a watch fully unwind and stop now and then seems like a smart thing to do.

[Dirt]

Larry gives a good explanation as to the main factor that is coming into play.

Accuracy and or precision can be influenced by a good number of factors.
The scenario you put forward is certainly one of those situations which I have observed with a number of my watches to some degree over the years.
It's also discussed throughout the legendary 32xx movement thread and it is recognised as having the capability of correcting accuracy variations, even if it's only a temporary or a transitory condition.
Accuracy can be a bit of a moving feast, even with a well set up movement and illusive with any movement that may need a proper service or is of low quality.

[Dirt]

Originally Posted by Tim Plains

Should be less accurate as the main spring unwinds. It's not like a rechargeable battery that should be depleted every once in a while and fully charged.

It's not really the same thing, but I get the analogy

[Chiboy]

Others on this thread know way more than me. But I like an accurate watch, and my Daytona has been super accurate. So at times I have tracked it. I know the haters will spew their usual hate, but I found it interesting. Anyway, a couple of times, the watch was like dead on day after day for months, just by once in a while changing its resting position at night. I should say that I wear mine every day, but not when exercising. Anyway, right before the watch finally conked out on its own, it became much less accurate, gaining or losing a couple of seconds a day. So that indicates to me that when it's not as wound as it could be, it loses some accuracy. Probably not between 100% wound and 20% wound, but once you get to the point where it's not got much left in reserve.

[burnthesehills]

Thanks for the information and advice, everyone. I’m going to try letting it wind down and then fully wind it again.

Does anyone here wind their watch in between? To top it off so to speak like once a week or no?

[Dirt]

Originally Posted by burnthesehills

Does anyone here wind their watch in between? To top it off so to speak like once a week or no?

No, not really.
Maybe I'll do it once every 6 months or so out of curiosity to see just how much wind is in it when I take the watch off and it's been a very quiet day, as one can feel if they're fully wound and in a bit of a rotation.
My wife's lady DJ often surprises me in that way, that it's fully wound even after a small number of hours on the wrist.
I don't fully wind an Automatic to start them. Just a few winds and or a little tap or shake to kick start them when stopped, then set the time and go is what we do around our place

[Rolex1982]

Originally Posted by burnthesehills

Thanks for the information and advice, everyone. I’m going to try letting it wind down and then fully wind it again.

Does anyone here wind their watch in between? To top it off so to speak like once a week or no?

I don’t, I’m currently on a 90 days run without winding and it still runs with the same accuracy. I can’t believe that a watch accuracy differs noticeably on 25% power reserve.

[Yess]

I wear my Sub every day for between 15-17 hours (put it on the night stand when I get into bed, reach over put it back on before I get up). Every day. I'm quite active as I farm with the watch on, and I don't take it off, no matter the task I'm doing. Every few weeks (2 but more often 3) I check the accuracy - the Sub I have is by far the most accurate watch I have ever owned. Sometimes it has not lost anytime at all.. At worst it is a second or two over two-three weeks. And always slower. I lay it face up of a night (when I was wearing the Air-King it was crown down, and the OP is crown up of night to keep the accuracy). I never wind the watch, just adjust the couple of second discrepancy and put it back on. I think keep it fully wound, which it does through 15+ hours of constant movement, daily, accounts for some the accuracy.

[burnthesehills]

Originally Posted by Yess

I wear my Sub every day for between 15-17 hours (put it on the night stand when I get into bed, reach over put it back on before I get up). Every day. I'm quite active as I farm with the watch on, and I don't take it off, no matter the task I'm doing. Every few weeks (2 but more often 3) I check the accuracy - the Sub I have is by far the most accurate watch I have ever owned. Sometimes it has not lost anytime at all.. At worst it is a second or two over two-three weeks. And always slower. I lay it face up of a night (when I was wearing the Air-King it was crown down, and the OP is crown up of night to keep the accuracy). I never wind the watch, just adjust the couple of second discrepancy and put it back on. I think keep it fully wound, which it does through 15+ hours of constant movement, daily, accounts for some the accuracy.

Interesting. Thank you!

[77T]

All other factors being equal, the mainspring tension alone does affect amplitude and therefore accuracy. (Of course they are never equal)

But some watchmakers have designed solutions to deliver a constant force while the mainspring unwinds.

Here is something IWC wrote”
“As the tension in the mainspring of a mechanical watch decreases, so too does the balance amplitude. This has a negative impact on the watch's accuracy. IWC's constant-force mechanism ensures that the escapement delivers an absolutely even supply of power and delivers unprecendented precision.

The only constant – so runs the adage – is change. In the world of haute horlogerie, however, its aptness is limited, because in watchmaking all our efforts are channelled into creating constancy: in other words, into ensuring that the oscillations in the balance are always exactly equal. For centuries now, one specific challenge has faced inventors and watchmakers. “When a watch is fully wound, the mainspring generates its maximum torque. And that results in
maximum amplitude. But as the tension in the barrel decreases, so too do the oscillations,” says Thomas Gäumann, Head of In-House Movements at IWC in Schaffhausen. This phenomenon has a negative effect on a mechanical watch’s accuracy.
For the balance oscillations to remain even at all times, the power transmitted through the wheel train and the escapement must likewise always be constant. However, as long as the flow of power to the balance is continuous, decreasing tension in the mainspring inevitably influences the amplitude. As Gäumann explains: "Various solutions have been designed with the aim of converting diminished energy from the spring into constant momentum with the help of an additional mechanism."

https://www.iwc.com/at/en/articles/e...9;s%20accuracy.

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[puma1552]

Say the watch is fully wound (let's say with 70 hour power reserve) and you then don't wear it for a full 48-60 hours. You then pick it up, it's still ticking along nicely as expected but you know the power reserve is low.

Is it recommended to manually wind it back up, or should you pretty much always leave it alone as long as it's going and only wind it when it's dead?

[77T]

If maximum accuracy is your goal, wind it up to full power reserve.

It does no harm and gives you tactile feedback from the crown if the mechanism is still smooth (or not).


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[Mystro]

If you do a power reserve test and check the accuracy at intervals as it winds down to a stop, you will see at what point accuracy noticeable falls. I do these tests once a year and generally accuracy is always optimal in the first 36-40 hours of the mainspring.

[dannyp]

Originally Posted by Rolex1982

There is a small relation between activity level and accuracy. If your not active, after a few days the power reserve is empty and it will stop. I cannot imagine that the accuracy will change over the course of the days. But that’s not based on any technical knowledge but only on my own experience. N = 1.

What I've observed is that accuracy will start to be affected after 1+ days of non-wearing. First, the watch starts to gain time, then begins to loose time before finally not keeping time at all.

On one of mine I've noticed that if I have it off for 1-2 days, it'll gain maybe 0.5-1s/day more than usual. Another day, though, and it's losing maybe 2s/day more than usual.

[padi56]

Originally Posted by burnthesehills

Let’s say for example I wear a Sub for several weeks or even months on end without winding it. Granted it is being automatically wound while worn by the rotor. But depending on activity level and time on the wrist (versus in a drawer) I assume the mainspring will eventually wind down to some degree. Could this affect accuracy in terms of the watch losing more time? Conversely, would letting the watch completely wind down and giving it a full wind with a fresh start so to speak be better for accuracy?

Or is there basically no relation?

Gravity is the main enemy of any mechanical movement no matter the make or calibre, when resting off wrist dial up or dial down the balance staff runs on the ends of it's pivots very little or no added friction. Thus the balance wheel has a slightly higher amplitude so will make movement run very slightly faster. When watch is off wrist vertical crown up or down or the balance staff pivots runs on the sides of the balance pivot causing a tiny more added friction this slows the amplitude so will run very slightly slower all this depends on the power-reserve in mainspring. In wearing through the day these positions hopefully balance out if watch is regulated correctly. A well regulated watch will have an amplitude of between 270 to 300 in different positions on full manual winding and all watches will be more accurate when mainspring is close to peak power. Now on one of these winding machines where the watch is normally in the same position 24/7 this too could vary compared to when watch on the wrist.

[RFC]

Originally Posted by Tools

Everything affects "accuracy", in that temperature, gravity, mainspring wind, etc., all determine how far apart the ticks are in each second.

Yes, you should let the mainspring completely unwind from time-to-time. Springs need to overcome their own friction when unwinding, so the inner, more tightly wound, layers are more compressed (more friction). Letting everything relax before re-winding can release some of this inherent torque-lock in an always tightly wound coil.

I would add that magnetism from unintended contact with modern electronics (including phones, laptops etc.) significantly affects accuracy/precision. I've seen this happen to the 1520 and even the 3130 movements.

[vesnyder]

that’s because I have a good vibe?

That's definitely true with my watches! I manually wind my watches I do not wear (forces me to keep the collection at a managemeable level!), but they all seem to prefer wearing vs the manual wind.

[burnthesehills]

Originally Posted by padi56

Gravity is the main enemy of any mechanical movement no matter the make or calibre, when resting off wrist dial up or dial down the balance staff runs on the ends of it's pivots very little or no added friction. Thus the balance wheel has a slightly higher amplitude so will make movement run very slightly faster. When watch is off wrist vertical crown up or down or the balance staff pivots runs on the sides of the balance pivot causing a tiny more added friction this slows the amplitude so will run very slightly slower all this depends on the power-reserve in mainspring. In wearing through the day these positions hopefully balance out if watch is regulated correctly. A well regulated watch will have an amplitude of between 270 to 300 in different positions on full manual winding and all watches will be more accurate when mainspring is close to peak power. Now on one of these winding machines where the watch is normally in the same position 24/7 this too could vary compared to when watch on the wrist.

Excellent information, thanks for sharing!