The SH4131 Daytonas - Long-term reliability test

[roger.w]

hope things are well and thank you for the test boss

 

[Rheinischerjung]

I'll do an update shortly, as soon as I'm over the miserable respiratory virus I have.

Hey @trailboss99 hope you are fine. Are there any news about your SH4131 after long term Test?
Greetings
Michael

 

[trailboss99]

Hey @trailboss99 hope you are fine. Are there any news about your SH4131 after long term Test?
Greetings
Michael

Life has been a little bit busy, as soon as I have a chance I'll do a report.

 

[dogwood]

I recently had one of these on my bench for a service. The movement in question was from an APSF watch. The movement was badly contaminated with metal dust (likely from the engraving process). I don’t think this is typically. Once cleaned up the movement went back together well and ticked nicely.

Dogwood's Watchmaking Journey

Hi so is it working with the gen balance? Thx Yes, the gen balance is a drop in replacement for the dd3285 balance.

forum.replica-watch.info

I also recent did a full service on a DD4131 and between the two I think the Dandong version is superior. If I were going to buy a 12-series Daytona I would opt for one with a Dandong movement.

Dogwood's Watchmaking Journey

Hi so is it working with the gen balance? Thx Yes, the gen balance is a drop in replacement for the dd3285 balance.

forum.replica-watch.info

 

[ToxicManChowder]

I recently had one of these on my bench for a service. The movement in question was from an APSF watch. The movement was badly contaminated with metal dust (likely from the engraving process). I don’t think this is typically. Once cleaned up the movement went back together well and ticked nicely.

Dogwood's Watchmaking Journey

Hi so is it working with the gen balance? Thx Yes, the gen balance is a drop in replacement for the dd3285 balance.

forum.replica-watch.info

I also recent did a full service on a DD4131 and between the two I think the Dandong version is superior. If I were going to buy a 12-series Daytona I would opt for one with a Dandong movement.

Dogwood's Watchmaking Journey

Hi so is it working with the gen balance? Thx Yes, the gen balance is a drop in replacement for the dd3285 balance.

forum.replica-watch.info

Is that why mine feels like sandpaper when I wind it? LOL!

 

[Watchfan12b]

To be honest I got the clean 126519 and the winding and everything at least for now feels better than the dd4130 on my clean panda and platona. For now it gives about +5-7 seconds a day. The platona with the dd4130 gives almost the same but the panda wit dd movement was +4-5 seconds a day but afte wearing as an everyday for about a year it started getting much bigger deviations, sometimes +20-30seconds a day sometimes +10 but not as good as in the begging

 

[dogwood]

To be honest I got the clean 126519 and the winding and everything at least for now feels better than the dd4130 on my clean panda and platona. For now it gives about +5-7 seconds a day. The platona with the dd4130 gives almost the same but the panda wit dd movement was +4-5 seconds a day but afte wearing as an everyday for about a year it started getting much bigger deviations, sometimes +20-30seconds a day sometimes +10 but not as good as in the begging

Timekeeping is a downstream indicator of movement health. What I mean is that just because timekeeping is good, doesn’t necessarily mean that the movement is still in good health. The best indicator of movement health is amplitude.

Let me explain. The hairspring + balance wheel combo on your watch is designed to beat four times per second if it is swung 270 degrees in each direction. Ideally the rate will stay very close to 4 beats per second even if the amplitude increases or decreases a bit. That’s why we say a “healthy range of amplitude is between 230 and 310”. But once you get outside this range you start to see timekeeping suffer.

For anyone with a math background this is because the higher order terms of the Taylor series of the sine / cosine functions become material outside of a specific range in amplitude, and the spring constant of the hairspring stops being a linear function of rotational displacement. Both ignoring higher order terms and assuming the spring constant is “constant” are necessary to find a simple solution to the differential equation that describes the harmonic oscillator of the balance wheel hairspring combo.

This is why looking at timekeeping results alone isn’t necessarily enough to gauge movement health. If timekeeping is bad, then the movement is in poor health. But if timekeeping is good, it doesn’t imply that the movement is healthy. Good timekeeping can be the result of an extremely linear response of the hairspring (maybe you won the hairspring linearity lottery) which allows the watch to keep time even if the amplitude is hugely outside the ideal range.

Another indicator is the amplitude drop between dial up/down and crown up/down positions. As a rule of thumb amplitude shouldn’t really drop more than 30 degrees when you measure in crown up/down vs dial up/down. If the amplitude drops by substantially more than 30 degrees it’s an indicator that there’s debris building up in the train wheel pivots.

 

[alex_corfu]

Nice inputs
Looking forward to more info since I have this watch as the next on my list!

 

[Messi]

It’s really you and your luck on the grittiness of the winding. I have a panda and a black dial. Ones smooth as can be and ones like grinding rocks. They both run great either way

 

[dogwood]

Something to consider about “gritty” feelings when winding a watch — it’s pretty unlikely that there’s debris in the teeth of the winding works of any watch. If there were debris there it could either be brass dust (from engraving) or Emory dust (for grinding); if it’s the former the steel winding pinions will win and the grit will turn to paste mixed with oil and grease, if it’s the latter the teeth will lose and eventually you won’t be able to wind your watch.

But my money is on most “gritty” winding not being debris at all. There are two things I’ve watch owners often mistake for “grittiness”:

1. The sound (and feeling) of the click ratcheting along as you wind the watch. The sound and feeling of the click doing its job is normal.
2. When the mainspring is fully wound on an automatic watch, the mainspring bridle will slide along the inside wall of the mainspring barrel. When the mainspring bridle slides it both sounds and feels “bad” / “different” since there’s variable resistance against your fingers winding the crown and there’s the sound of metal sliding on metal. I strongly suspect that many people (but not all) call this “gritty” winding, when it’s just the queue to stop manually winding your watch. NB: this doesn’t apply to non-automatic watches since those don’t have a mainspring bridle that is designed to slip.

 

[themaxx25]

@joshhb8282

 

[Dexxter]

I recently had one of these on my bench for a service. The movement in question was from an APSF watch. The movement was badly contaminated with metal dust (likely from the engraving process). I don’t think this is typically. Once cleaned up the movement went back together well and ticked nicely.

Dogwood's Watchmaking Journey

Hi so is it working with the gen balance? Thx Yes, the gen balance is a drop in replacement for the dd3285 balance.

forum.replica-watch.info

I also recent did a full service on a DD4131 and between the two I think the Dandong version is superior. If I were going to buy a 12-series Daytona I would opt for one with a Dandong movement.

Dogwood's Watchmaking Journey

Hi so is it working with the gen balance? Thx Yes, the gen balance is a drop in replacement for the dd3285 balance.

forum.replica-watch.info

Hi dogwood, thank you for the review. Do you think it´s worth inserting a dd4131 into a clean case, or does it not make any sense if there is no real need for it? My SH is running very well with +/- 1 sec. per day.

 

[NOTT3]

Timekeeping is a downstream indicator of movement health. What I mean is that just because timekeeping is good, doesn’t necessarily mean that the movement is still in good health. The best indicator of movement health is amplitude.

Let me explain. The hairspring + balance wheel combo on your watch is designed to beat four times per second if it is swung 270 degrees in each direction. Ideally the rate will stay very close to 4 beats per second even if the amplitude increases or decreases a bit. That’s why we say a “healthy range of amplitude is between 230 and 310”. But once you get outside this range you start to see timekeeping suffer.

For anyone with a math background this is because the higher order terms of the Taylor series of the sine / cosine functions become material outside of a specific range in amplitude, and the spring constant of the hairspring stops being a linear function of rotational displacement. Both ignoring higher order terms and assuming the spring constant is “constant” are necessary to find a simple solution to the differential equation that describes the harmonic oscillator of the balance wheel hairspring combo.

This is why looking at timekeeping results alone isn’t necessarily enough to gauge movement health. If timekeeping is bad, then the movement is in poor health. But if timekeeping is good, it doesn’t imply that the movement is healthy. Good timekeeping can be the result of an extremely linear response of the hairspring (maybe you won the hairspring linearity lottery) which allows the watch to keep time even if the amplitude is hugely outside the ideal range.

Another indicator is the amplitude drop between dial up/down and crown up/down positions. As a rule of thumb amplitude shouldn’t really drop more than 30 degrees when you measure in crown up/down vs dial up/down. If the amplitude drops by substantially more than 30 degrees it’s an indicator that there’s debris building up in the train wheel pivots.

My 4130dd is very smooth in the charging phase; the only anomaly is that if I test it immediately after having it on my wrist it gives me an amplitude of about 300-310 with a high dial trend of about +3 with very few variations in the other positions (in the order of +/- 4 seconds).
However, after only 20-30 minutes, with the watch stopped, the amplitude drops to about 280 with the high dial, a trend of -4/-5 seconds, with more consistent variations when I change position.
What do you think?

 

[dogwood]

Hi dogwood, thank you for the review. Do you think it´s worth inserting a dd4131 into a clean case, or does it not make any sense if there is no real need for it? My SH is running very well with +/- 1 sec. per day.

I wouldn’t. The sh4131 is a perfectly adequate movement. I’d say it’s roughly the same difference as the vr3235 to the vs3235 — both are good, but the vs3235 is better(*). If your sh4131 is running well there’s no need to replace it.

* in my my opinion

 

[dogwood]

My 4130dd is very smooth in the charging phase; the only anomaly is that if I test it immediately after having it on my wrist it gives me an amplitude of about 300-310 with a high dial trend of about +3 with very few variations in the other positions (in the order of +/- 4 seconds).
However, after only 20-30 minutes, with the watch stopped, the amplitude drops to about 280 with the high dial, a trend of -4/-5 seconds, with more consistent variations when I change position.
What do you think?

Perfectly normal. It’s not uncommon for movements to display slightly higher amplitude after they’ve been fully wound. Then as the mainspring settles, the amplitude will drop slightly.

 

[Dexxter]

I wouldn’t. The sh4131 is a perfectly adequate movement. I’d say it’s roughly the same difference as the vr3235 to the vs3235 — both are good, but the vs3235 is better(*). If your sh4131 is running well there’s no need to replace it.

* in my my opinion

It runs well. Only the winding sound is strange. It´s a clicking. Never had that on my other SH4131 movement.

 

[Watchfan12b]

Timekeeping is a downstream indicator of movement health. What I mean is that just because timekeeping is good, doesn’t necessarily mean that the movement is still in good health. The best indicator of movement health is amplitude.

Let me explain. The hairspring + balance wheel combo on your watch is designed to beat four times per second if it is swung 270 degrees in each direction. Ideally the rate will stay very close to 4 beats per second even if the amplitude increases or decreases a bit. That’s why we say a “healthy range of amplitude is between 230 and 310”. But once you get outside this range you start to see timekeeping suffer.

For anyone with a math background this is because the higher order terms of the Taylor series of the sine / cosine functions become material outside of a specific range in amplitude, and the spring constant of the hairspring stops being a linear function of rotational displacement. Both ignoring higher order terms and assuming the spring constant is “constant” are necessary to find a simple solution to the differential equation that describes the harmonic oscillator of the balance wheel hairspring combo.

This is why looking at timekeeping results alone isn’t necessarily enough to gauge movement health. If timekeeping is bad, then the movement is in poor health. But if timekeeping is good, it doesn’t imply that the movement is healthy. Good timekeeping can be the result of an extremely linear response of the hairspring (maybe you won the hairspring linearity lottery) which allows the watch to keep time even if the amplitude is hugely outside the ideal range.

Another indicator is the amplitude drop between dial up/down and crown up/down positions. As a rule of thumb amplitude shouldn’t really drop more than 30 degrees when you measure in crown up/down vs dial up/down. If the amplitude drops by substantially more than 30 degrees it’s an indicator that there’s debris building up in the train wheel pivots.

Really interesting, thank you for this information!