Chronograph Usage & 24/7 Watch Accuracy

[BristolCavendish]

I ran this query past Adam/OEP and he suggested posting it for further insights/experiences from TRFers who own chronographs of various types (i.e. mechanical/quartz/meca-quartz etc.)

An acquaintance noticed that the day-to-day accuracy of his Rolex Daytona and Seiko/quartz chronographs tends to fluctuate (albeit minimally) when he uses the stop watch functions on a regular basis compared to the watch running sans any usage of this feature. This topic has apparently been discussed on other watch forums but the answer is still somewhat inconclusive as some respondents have noted that regular chronograph operation can affect the watch's overall daily accuracy while others haven't noticed any deviations.

So the question is: Depending on the watch design, can the power reserve (whether mainspring or battery), type of movement (mechanical or quartz/step motor), along with the type of chronograph linkage/switching (hammer & lever vs servo) actually create a slight deviance in the watch's 24/7 accuracy?

It should be noted that the Daytona in question incorporates a Valjoux 72 movement (manual wind) so it might be conceivable that the lessening of the mainspring during the course of the day has an effect. On the other hand, a perpetual movement (if fully wound) should in theory provide a more consistent source of continual power. Compounding this puzzle is that on his Seiko chronograph (battery-powered with three step motors) his continual daily fidgeting with the chronograph functions also seems to affect the watch's day-to-day accuracy (more noticeable over a period of non-date changing months). Would an increase in battery drain during chronograph usage (or a weakening battery) be a key factor in this instance?

While investigating the topic, I came across this 2014 thread on WatchUSeek and the responses were somewhat varied as well.

http://forums.watchuseek.com/f2/chro...cy-969379.html

Curious. For those of you who own chronographs, have you noticed any 24/7 accuracy deviations when using the chronograph feature frequently?

[SearChart]

When a mechanical chronograph is engaged the balance amplitude will drop a few degrees which might have a very small effect on the accuracy. It has however no effect on the power reserve as the mainspring isn't running down any faster simply because the chrono is engaged.

In a quartz movement every function other than time means more friction, thus more energy consumption.

[FeelingTheBlues]

Originally Posted by SearChart

When a mechanical chronograph is engaged the balance amplitude will drop a few degrees which might have a very small effect on the accuracy. It has however no effect on the power reserve as the mainspring isn't running down any faster simply because the chrono is engaged.

In a quartz movement every function other than time means more friction, thus more energy consumption.

I agree with you on the mechanical chronograph, however, it has to be said that on quartz movements there are certain calibers in which the stop watch function has its own rotor and coil, thus not adding any friction to the gear train and only affecting the battery energy reserve.

BC, whether or not you can notice it or not, the rule of thumb is that letting the stop watch run on a mechanical watch can and most probably affect its accuracy to a certain extent.

[Old Expat Beast]

Originally Posted by FeelingTheBlues

I agree with you on the mechanical chronograph, however, it has to be said that on quartz movements there are certain calibers in which the stop watch function has its own rotor and coil, thus not adding any friction to the gear train and only affecting the battery energy reserve.

BC, whether or not you can notice it or not, the rule of thumb is that letting the stop watch run on a mechanical watch can and most probably affect its accuracy to a certain extent.

Carl, would this also apply to chrono modules? My Tudor Heritage Chrono has run for months on end with the stopwatch hand running, and keeps perfect time with overnight positioning (never more than plus or minus a few seconds over several months) and so never needs re-setting. It actually performs better in this regard than any of my Tudor or Rolex watches.

[BristolCavendish]

Running with Bas' clarification/explanation and for lack of a better analogy on my part, switching to the chronograph function on a mechanical watch seems to be like changing gears (upward) in an automotive transmission. In other words, for a brief moment some power is lost/transferred during the shifting process but forward motion and speed remains somewhat intact.

In regards to Carl's insights on the quartz chronograph, running multiple step motors to accommodate the various chronograph features can drain battery power and friction becomes an issue when just one step motor is being used to operate additional functions. This factor might be a consideration if one is opting towards a meca-quartz type chronograph (where its mechanical feel and characteristic is based on using a one step motor + a hammer/lever linkage on the chronograph operation). This would seemingly infer that the single step motor is working harder to accommodate a number of functions (added friction/resistance = more battery drain). It should also be noted that on a meca-quartz movement, the stopwatch second hand actually 'sweeps' in 1/5-1/8 second increments separate from the 1 second blip of the second hand. The two second hands are oscillating at different frequencies off the one step motor.

In Adam's/OEP's case, his stopwatch second hand is running full-time on a mechanical movement and he has experienced exceptional timekeeping. Outside of possible wear and tear from the continual running of the chronograph function, has the mechanism on his Tudor simply stabilized to this continual operation?

[Old Expat Beast]

Originally Posted by BristolCavendish

Running with Bas' clarification/explanation and for lack of a better analogy on my part, switching to the chronograph function on a mechanical watch seems to be like changing gears (upward) in an automotive transmission. In other words, for a brief moment some power is lost/transferred during the shifting process but forward motion and speed remains somewhat intact.

In regards to Carl's insights on the quartz chronograph, running multiple step motors to accommodate the various chronograph features can drain battery power and friction becomes an issue when just one step motor is being used to operate additional functions. This factor might be a consideration if one is opting towards a meca-quartz type chronograph (where its mechanical feel and characteristic is based on using a one step motor + a hammer/lever linkage on the chronograph operation). This would seemingly infer that the single step motor is working harder to accommodate a number of functions (added friction/resistance = more battery drain).

In Adam's/OEP's case, his stopwatch second hand is running full-time on a mechanical movement and he has experienced exceptional timekeeping. Outside of possible wear and tear from the continual running of the chronograph function, has the mechanism on his Tudor simply stabilized to this continual operation?

It was like that from Day One.

[BristolCavendish]

Originally Posted by SearChart

When a mechanical chronograph is engaged the balance amplitude will drop a few degrees which might have a very small effect on the accuracy. It has however no effect on the power reserve as the mainspring isn't running down any faster simply because the chrono is engaged.

As opposed to keeping the chrono/second hand running continuously, would turning the stopwatch function on-off/on-off several times a day have an accrued effect on the overall accuracy of the watch?

In my initial correspondence with Adam, I cited an acquaintance who brought this variance to my attention. On the other hand, this particular individual is constantly playing with the chronograph function on his Daytona (either out of boredom, for personal entertainment or perhaps nervousness). I keep telling him that one of these days he's gonna wear out the pushers. Though a slight exaggeration, the guy fidgets with his chronograph like Captain Queeg with his marbles.

[breitlings]

I think the performance will depend on the type of chrono and it's particular execution. The accuracy will likely be different but should still run within cosc or better and be predictable. I've seen the accuracy be off by about .5 spd vs not running the chrono.

[FeelingTheBlues]

Originally Posted by Old Expat Beast

Carl, would this also apply to chrono modules? My Tudor Heritage Chrono has run for months on end with the stopwatch hand running, and keeps perfect time with overnight positioning (never more than plus or minus a few seconds over several months) and so never needs re-setting. It actually performs better in this regard than any of my Tudor or Rolex watches.

I will say yes simply because of the fact that the stop watch function, albeit being modular, depends on the main gear train to run and therefore it takes energy that would otherwise be giving the balance wheels those extra oscillating degrees and, indeed, ensuring a proper accuracy in the movement.

Still, it has to be said that this consequence of letting a chronograph run continuously is from a technical aspect. In the grand scheme of things, well built chrono movements take this in account and rarely have I seen this being a real problem. My main concern lies within the risk of having something blocking your modular and, soon after, your watch if it runs continuously.

Am I right in thinking your Tudor holds the Valjoux 7750? As far as I am concerned it remains a movement with a rather good reputation in the world of horology.

[Old Expat Beast]

Originally Posted by FeelingTheBlues

I will say yes simply because of the fact that the stop watch function, albeit being modular, depends on the main gear train to run and therefore it takes energy that would otherwise be giving the balance wheels those extra oscillating degrees and, indeed, ensuring a proper accuracy in the movement.

Still, it has to be said that this consequence of letting a chronograph run continuously is from a technical aspect. In the grand scheme of things, well built chrono movements take this in account and rarely have I seen this being a real problem. My main concern lies within the risk of having something blocking your modular and, soon after, your watch if it runs continuously.

Am I right in thinking your Tudor holds the Valjoux 7750? As far as I am concerned it remains a movement with a rather good reputation in the world of horology.

Thanks Carl. Movement is a 2892, with a DD module.

[FeelingTheBlues]

Originally Posted by BristolCavendish

As opposed to keeping the chrono/second hand running continuously, would turning the stopwatch function on-off/on-off several times a day have an accrued effect on the overall accuracy of the watch?

In my initial correspondence with Adam, I cited an acquaintance who brought this variance to my attention. On the other hand, this particular individual is constantly playing with the chronograph function on his Daytona (either out of boredom, for personal entertainment or perhaps nervousness). I keep telling him that one of these days he's gonna wear out the pushers. Though a slight exaggeration, the guy fidgets with his chronograph like Captain Queeg with his marbles.

Methinks your acquaintance doth push them pushers with the strength with which I pick my nose if he wears them out. A Breitling Chronomat pushers can withstand about 1500 clicks in between two services if memory serves, I will go out on a limb and suppose his Daytona can do the same and would survive his habit of using the stop watch function like it's the last thing he does.

Are you guys acquainted enough for you to investigate on this matter? Given your talent of telling stories, how about you tell him about that fun fact and come back to me with what he says?

[FeelingTheBlues]

Originally Posted by Old Expat Beast

Thanks Carl. Movement is a 2892, with a DD module.

You should be good then.

And don't you dare banning me if I jinxed it, I'm watching you, young man!

[Old Expat Beast]

Originally Posted by FeelingTheBlues

You should be good then.

And don't you dare banning me if I jinxed it, I'm watching you, young man!

[SearChart]

Originally Posted by Old Expat Beast

Thanks Carl. Movement is a 2892, with a DD module.

That thing is a pain to get back together


I don't think you're lucky it runs that well, modern watch movements are very precisely machined so this slight loss of amplitude will have little to no effect.

Now on an older movement (50years+) there might already be a lower amplitude, dropping it further can definitely cause it to be off a few seconds.

A balance should in theory have it's center of mass exactly in the middle. But the watch gets serviced, it's knocked around, and they didn't have CNC machining back then so in reality it's not really in the middle.
If the amplitude drops significantly gravity will then have more effect on that slight deviation.
The lower the amplitude the more affected the balance gets, up until 220degrees where they found out that an imperfect balance is pretty much unaffected. Then if it gets even lower (below 220degrees amplitude) the effect gets stronger.

I've seen movements with extremely bad timekeeping, simply calculating where the center mass is located on the balance wheel and then taking a little material away completely fixes this problem.

Now like I said earlier, if a vintage watch is running within specs then I'd only expect a little loss of accuracy when engaging the chronograph and pretty much none in a modern watch.
I hope my explanation for this is easy to understand for a non-watchmaker.

[SearChart]

Originally Posted by FeelingTheBlues

I agree with you on the mechanical chronograph, however, it has to be said that on quartz movements there are certain calibers in which the stop watch function has its own rotor and coil, thus not adding any friction to the gear train and only affecting the battery energy reserve.

BC, whether or not you can notice it or not, the rule of thumb is that letting the stop watch run on a mechanical watch can and most probably affect its accuracy to a certain extent.

I meant that there was more friction overall (extra gear trains, coils etc) as in it costs more energy to power a chronograph than it would in a time-only quartz movement.

[douglasf13]

Originally Posted by SearChart

That thing is a pain to get back together


I don't think you're lucky it runs that well, modern watch movements are very precisely machined so this slight loss of amplitude will have little to no effect.

Now on an older movement (50years+) there might already be a lower amplitude, dropping it further can definitely cause it to be off a few seconds.

A balance should in theory have it's center of mass exactly in the middle. But the watch gets serviced, it's knocked around, and they didn't have CNC machining back then so in reality it's not really in the middle.
If the amplitude drops significantly gravity will then have more effect on that slight deviation.
The lower the amplitude the more affected the balance gets, up until 220degrees where they found out that an imperfect balance is pretty much unaffected. Then if it gets even lower (below 220degrees amplitude) the effect gets stronger.

I've seen movements with extremely bad timekeeping, simply calculating where the center mass is located on the balance wheel and then taking a little material away completely fixes this problem.

Now like I said earlier, if a vintage watch is running within specs then I'd only expect a little loss of accuracy when engaging the chronograph and pretty much none in a modern watch.
I hope my explanation for this is easy to understand for a non-watchmaker.

Want to know something wild? Our grandmother left us a gold, 112 year old pocket watch that had been sitting in a safety deposit for an unspecified length of time. I decided to crank it up a few weeks ago, and it ran -2 secs for three days sitting on my desk, and then I stopped winding it. Crazy. I have no idea of when the last time it was serviced. Potentially never.

[SearChart]

Originally Posted by BristolCavendish

Running with Bas' clarification/explanation and for lack of a better analogy on my part, switching to the chronograph function on a mechanical watch seems to be like changing gears (upward) in an automotive transmission. In other words, for a brief moment some power is lost/transferred during the shifting process but forward motion and speed remains somewhat intact.

It's not brief. When you press that button the gear train suddenly needs to push some extra gears and it keeps doing that untill it's stopped.
This costs energy and there is only one source which is the mainspring in the barrel.
This means that not all power reaches the balance thus it gets pushed less hard by the pallet fork thus lowering the amplitude.

[SearChart]

Originally Posted by douglasf13

Want to know something wild? Our grandmother left us a gold, 112 year old pocket watch that had been sitting in a safety deposit for an unspecified length of time. I decided to crank it up a few weeks ago, and it ran -2 secs for three days sitting on my desk, and then I stopped winding it. Crazy. I have no idea of when the last time it was serviced. Potentially never.

Now that is cool!

Edit: does your pocket watch lay flat?

The effect I explained is only there in vertical position (crow up, down, left, right) not when it's dial up or down (flat).

[Andad]

After a full wind my Daytona runs about for about 2.5 - 3.0 hours less with the chrono running.

And when it stops in the chrono running mode it stops with the chrono hand at the 60 second market 4 times out if 5.

I think it needs more power to run the chrono therefore stops earlier.

Haven't checked the difference in s/d on my T'Grapher 1000 between chrono on and off but will do.

[douglasf13]

Originally Posted by SearChart

Now that is cool!

Edit: does your pocket watch lay flat?

The effect I explained is only there in vertical position (crow up, down, left, right) not when it's dial up or down (flat).

Yeah, just flat, but I was still pretty amazed.

[BristolCavendish]

Originally Posted by FeelingTheBlues

A Breitling Chronomat pushers can withstand about 1500 clicks in between two services if memory serves, I will go out on a limb and suppose his Daytona can do the same and would survive his habit of using the stop watch function like it's the last thing he does.

Let's see now, 10-12 'compulsive' on/off/resets (3 x 12 per day) on the pushers of a chronograph comes to roughly 12,000 clicks per year (or approximately 60,000 over a 5-year pre-service period). Are the Daytona pushers designed to withstand that much usage? Running with your clarifications + Bas' explanation of the chronograph movement, this older/manual wind Daytona/Valjoux 72 must be taking one hell of an internal beating (no pun intended).

Curious. Is there a potential breakdown of lubrication and/or premature gasket wear going on as well?

Originally Posted by FeelingTheBlues

Are you guys acquainted enough for you to investigate on this matter? Given your talent of telling stories, how about you tell him about that fun fact and come back to me with what he says?

Probably why he has a Seiko quartz/3-step motor chronograph as a 'back-up' for his affliction.

[SearChart]

Originally Posted by BristolCavendish

Let's see now, 10-12 'compulsive' on/off/resets (3 x 12 per day) on the pushers of a chronograph comes to roughly 12,000 clicks per year (or approximately 60,000 over a 5-year pre-service period). Are the Daytona pushers designed to withstand that much usage? Running with your clarifications + Bas' explanation of the chronograph movement, this older/manual wind Daytona/Valjoux 72 must be taking one hell of an internal beating (no pun intended).

Curious. Is there a potential breakdown of lubrication and/or premature gasket wear going on as well?

Probably why he has a Seiko quartz/3-step motor chronograph as a 'back-up' for his affliction.

With this kind of use you'll obviously find wear marks on friction points after a while. Will it break eventually? It might, it might not.

[FeelingTheBlues]

Originally Posted by SearChart

With this kind of use you'll obviously find wear marks on friction points after a while. Will it break eventually? It might, it might not.

Indeed, that is quite a bit.

Now the question of the day: a customer brings you a watch that he uses in a similar manner, do you worry more about the pushers/levers/gaskets being moved and rubbed against constantly or the wearer's fingers?

[BristolCavendish]

Originally Posted by FeelingTheBlues

Indeed, that is quite a bit.

Now the question of the day: a customer brings you a watch that he uses in a similar manner, do you worry more about the pushers/levers/gaskets being moved and rubbed against constantly or the wearer's fingers?

As in a bad case of blisters?

While TRF focuses primarily on Rolexes and watches with mechanical movements, I'm somewhat curious why the less-expensive Seiko 'meca-quartz' movement (i.e. a 6t63) with its one-step motor can provide two different operating frequencies (a one second 'blip' on the regular second hand + a higher frequency 'sweep' on the chronograph second hand). As a result, a meca-quartz chronograph can measure at 1/5-1/8 split second increments.

Comparatively, the costlier (and more complex) multi-step motor Seiko chronographs 'blip' at one second intervals on the chronograph second hand rendering a less accurate sub-second reading. Plus it 'rotates' back to 12 on reset rather than 'fast-clicking' like a meca-quartz with its hybrid hammer/lever chronograph design. One would think that these extra step motors could be put to better use (especially on the chronograph function).

[SearChart]

Originally Posted by FeelingTheBlues

Indeed, that is quite a bit.

Now the question of the day: a customer brings you a watch that he uses in a similar manner, do you worry more about the pushers/levers/gaskets being moved and rubbed against constantly or the wearer's fingers?

I'd definitely be more worried about the watch