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Okeedokee but...

"...Does not lower the power reserve; that's a myth. No, it's not a myth. When the chrono is running, the mainspring has more work to do. Sure, it won't run down any faster, but it will reach a point where there's not enough strength left to keep the movement going..."

Sooooooo....
View attachment 15504544
So you are reframing the question to suit your needs. Not unexpected, so let’s revisit your original claim...

"and they also lower your power reserve"

And you went on to describe this as:

"the watch will run out of power faster"

It's clear from my posts that the watch will stop sooner with the chronograph running. On that we agree, however you attribute this to it somehow using power "faster" which is completely incorrect, and actually not possible.

Again the power reserve is designed into the movement, and is based on the length of the mainspring, which in turn determines how many revolutions the barrel will make. The barrel in a Speedmaster Pro for example, turn the center wheel, and the center wheel has the cannon pinion fitted to it - the minute hand goes right on the cannon pinion. The gear ratio between the barrel teeth and the center wheel pinion determine how many revolutions of the center wheel will happen before the mainspring stops unwinding - that is the power reserve. As I've said, that doesn't change unless the length of the mainspring changes, or the ratio of the gearing changes.

The formula for this is as follows:

n2/n1 = Z1/Z2

Where:

Z1 - number of teeth in the barrel
Z2 - number of teeth in the center pinion
n1 - number of revolutions of the barrel
n2 - number of revolutions of the center pinion

This formula is from The Theory of Horology, which is the textbook used for most watchmaking schools (WOSTEP, SAWTA, etc.).

What does change is the load on the movement side, so that can be from a chronograph running, a date change mechanism, or simply lack of maintenance with dried up oils and debris or wear in the movement. But none of these things cause the spring to unwind faster, or the torque level of the spring to drop off faster, which was your original assertion. This is simply incorrect, and doing the simple test I've described above would illustrate that for you if you really wanted to understand this.

In fact a number of years ago there were a number of people here in the Omega section that did this very test, and the results were compiled into a thread. The search function on this site is so bad I haven't been able to find it, but if someone out there can find it, it would help people understand this more completely.

If you want to claim this is just a semantic argument that's fine, but there is a material difference in the two ideas that I'm not sure you fully understand (or admit to) yet.

But if you want to claim that this is still wrong somehow, and go against hundreds of years of horological knowledge, hey you be you man... :)

Good talk.

Cheers, Al
 

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My career was that of a Mechanical Design Engineer of over 30 years.
Archer/Al is and has been 100% correct in his supplied information concerning this Chronograph subject.
Feel free to continue the arguments. If you do, you know not of what you speak, or else you are just confused.
 

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So you are reframing the question to suit your needs. Not unexpected, so let’s revisit your original claim...

"and they also lower your power reserve"

And you went on to describe this as:

"the watch will run out of power faster"

It's clear from my posts that the watch will stop sooner with the chronograph running. On that we agree, however you attribute this to it somehow using power "faster" which is completely incorrect, and actually not possible.

Again the power reserve is designed into the movement, and is based on the length of the mainspring, which in turn determines how many revolutions the barrel will make. The barrel in a Speedmaster Pro for example, turn the center wheel, and the center wheel has the cannon pinion fitted to it - the minute hand goes right on the cannon pinion. The gear ratio between the barrel teeth and the center wheel pinion determine how many revolutions of the center wheel will happen before the mainspring stops unwinding - that is the power reserve. As I've said, that doesn't change unless the length of the mainspring changes, or the ratio of the gearing changes.

The formula for this is as follows:

n2/n1 = Z1/Z2

Where:

Z1 - number of teeth in the barrel
Z2 - number of teeth in the center pinion
n1 - number of revolutions of the barrel
n2 - number of revolutions of the center pinion

This formula is from The Theory of Horology, which is the textbook used for most watchmaking schools (WOSTEP, SAWTA, etc.).

What does change is the load on the movement side, so that can be from a chronograph running, a date change mechanism, or simply lack of maintenance with dried up oils and debris or wear in the movement. But none of these things cause the spring to unwind faster, or the torque level of the spring to drop off faster, which was your original assertion. This is simply incorrect, and doing the simple test I've described above would illustrate that for you if you really wanted to understand this.

In fact a number of years ago there were a number of people here in the Omega section that did this very test, and the results were compiled into a thread. The search function on this site is so bad I haven't been able to find it, but if someone out there can find it, it would help people understand this more completely.

If you want to claim this is just a semantic argument that's fine, but there is a material difference in the two ideas that I'm not sure you fully understand (or admit to) yet.

But if you want to claim that this is still wrong somehow, and go against hundreds of years of horological knowledge, hey you be you man... :)

Good talk.

Cheers, Al
Archer, as always, excellent. deep-understanding info from you. Much appreciated...(y)

Like you I used to "hate" the Search function until I got good at it - read a little bit how to use (there are some notes somewhere by the Admin how to use the features) & I found this thread - look at post #5 - everything tabulated so it's very easy to read & conclude for oneself....


"Does Running the Chronograph on my Speedy reduced the Power Reserve"
 

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Discussion Starter #24
If it’s a recently acquired new watch and you’ve only had for over a year it won’t need to be serviced anytime soon. At least not for another 4 years or more. Omega claims that coaxial technology cuts down on movement wear and therefore frequency of service. I would just go by the timekeeping. If the watch is keeping good time and all functions work properly then no need to service it. Why fix it if it ain’t broke? If it starts losing time significantly or the chrono functions stop working as they should then it’s different story.
Solid advice Paul! Thank you again for your time and expertise. Since the watch was bought new I’m sure that I have plenty of time before I bring it in for service. I’ll keep an eye on the chronograph functions and how it keeps time. Have a great rest of your day.
 

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Archer, as always, excellent. deep-understanding info from you. Much appreciated...(y)

Like you I used to "hate" the Search function until I got good at it - read a little bit how to use (there are some notes somewhere by the Admin how to use the features) & I found this thread - look at post #5 - everything tabulated so it's very easy to read & conclude for oneself....


"Does Running the Chronograph on my Speedy reduced the Power Reserve"
Thanks for finding that. The results there show without question that the power isn’t being used up faster, and that the laws of thermodynamics are still intact. ;)
 

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Well I stand corrected. Now I need to research and figure out why, because the laws of thermodynamics are not being broken.
 

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Well I stand corrected. Now I need to research and figure out why, because the laws of thermodynamics are not being broken.
LOL!! this crazy thing called Physics always wins!! :p

no need to figure it out - Archer has already done it for you in post #21...
 

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I found this entire thread to be very informative, particularly as I had similar concerns regarding a chronograph but I now feel more comfortable owning and operating one. Thanks everyone!
 

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LOL!! this crazy thing called Physics always wins!! :p

no need to figure it out - Archer has already done it for you in post #21...
No he didnt. Not all all from a physics point of view. Depending upon design we know amplitude can decrease.

So I'm thinking the spring must have unused energy on every normal beat. When the chrono is engaged some of that extra energy drives the chrono.
 

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Hi There

I’m admittedly a new watch owner. I’ve attached a picture of the Omega Speedmaster I’ve had for a little over a year. I certainly didn’t know much about it’s functions this last year. I even left the chronograph running for a year thinking it was the second hand. I have two questions and any help would be greatly appreciated. First question, did I do any damage by leaving the chronograph running for over a year? Also I have pressed the reset on the watch a few times while the chronograph is in motion. Has that caused any damage that needs servicing? Again, I didn’t realize that was a stop watch function and thought it was the second hand. Please let me know your thoughts. Thank you. View attachment 15504097
You've ruined your watch, it may be worth $500 now, but I'd be willing to give you $600 for it ;)

But seriously, it's fine. Some chronographs run all the time by design. The Zenith El Primero Retrotimer comes to mind (which is an amazing watch I will add).
 

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No he didnt. Not all all from a physics point of view. Depending upon design we know amplitude can decrease.

So I'm thinking the spring must have unused energy on every normal beat. When the chrono is engaged some of that extra energy drives the chrono.
You are overthinking it. The torque curve of a mainspring unwinding isn't flat - it decreases over time, yet the watch still runs. Graphic illustration of a torque curve showing toque compared to turns of the mainspring barrel:



This would tell you immediately that there's more torque there than is needed to drive the wheel train when the watch is fully wound. So add some loads from a chronograph running, a date change, or whatever other complication you want - if the torque being delivered from the mainspring is still enough to overcome those loads, the watch will still run. If it doesn't it will stop.

If you have a chronograph like a Speedmaster, try the test I've described. It will not only illustrate the concept very clearly, it will also demonstrate where the peak load is. When the chronograph is running, the load it adds is not constant. There is a fairly constant load for most of the time, but when the minute counter engages and starts to flip, there is a spring on the minute counter jumper that needs to be overcome. This is the peak load spot and why if you do this test, the watch will likely stop right when the chronograph seconds recording hand is at 58 or 59 seconds, just before the flip of that minute counter.

If you watch it run down, right new the end before it stops you will see that it will just barely get the flip done, and then have no problem doing the next round of the dial.

A spring has a set amount of energy in it that is released at a constant rate in a watch. Adding loads doesn't somehow cause that energy to be released faster as our friend Mickey believes. That would certainly be something that the laws of physics would have trouble with...but what I've described? Not so much...

Cheers, Al
 

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You are overthinking it. The torque curve of a mainspring unwinding isn't flat - it decreases over time, yet the watch still runs. Graphic illustration of a torque curve showing toque compared to turns of the mainspring barrel:



This would tell you immediately that there's more torque there than is needed to drive the wheel train when the watch is fully wound.

Cheers, Al
Not overthinking it since I came to the same conclusion after my initial hypothesis was deemed incorrect. No need to run a test we are on the same page. But thanks for the great explanation!

Mickey usually has reasonable posts other than his stance on Tudor. He'll come around on both 😄
 

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My career was that of a Mechanical Design Engineer of over 30 years.
Archer/Al is and has been 100% correct in his supplied information concerning this Chronograph subject.
Feel free to continue the arguments. If you do, you know not of what you speak, or else you are just confused.
From one former engineer to another, thanks for jumping in.

Cheers, Al
 

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Al,

Thanks for having the patience to explain this to us all. I, for one, have learned a great deal from this thread.

Best,

Rene
 
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So you are reframing the question to suit your needs. Not unexpected, so let’s revisit your original claim...

"and they also lower your power reserve"

And you went on to describe this as:

"the watch will run out of power faster"

It's clear from my posts that the watch will stop sooner with the chronograph running. On that we agree, however you attribute this to it somehow using power "faster" which is completely incorrect, and actually not possible.

Again the power reserve is designed into the movement, and is based on the length of the mainspring, which in turn determines how many revolutions the barrel will make. The barrel in a Speedmaster Pro for example, turn the center wheel, and the center wheel has the cannon pinion fitted to it - the minute hand goes right on the cannon pinion. The gear ratio between the barrel teeth and the center wheel pinion determine how many revolutions of the center wheel will happen before the mainspring stops unwinding - that is the power reserve. As I've said, that doesn't change unless the length of the mainspring changes, or the ratio of the gearing changes.

The formula for this is as follows:

n2/n1 = Z1/Z2

Where:

Z1 - number of teeth in the barrel
Z2 - number of teeth in the center pinion
n1 - number of revolutions of the barrel
n2 - number of revolutions of the center pinion

This formula is from The Theory of Horology, which is the textbook used for most watchmaking schools (WOSTEP, SAWTA, etc.).

What does change is the load on the movement side, so that can be from a chronograph running, a date change mechanism, or simply lack of maintenance with dried up oils and debris or wear in the movement. But none of these things cause the spring to unwind faster, or the torque level of the spring to drop off faster, which was your original assertion. This is simply incorrect, and doing the simple test I've described above would illustrate that for you if you really wanted to understand this.

In fact a number of years ago there were a number of people here in the Omega section that did this very test, and the results were compiled into a thread. The search function on this site is so bad I haven't been able to find it, but if someone out there can find it, it would help people understand this more completely.

If you want to claim this is just a semantic argument that's fine, but there is a material difference in the two ideas that I'm not sure you fully understand (or admit to) yet.

But if you want to claim that this is still wrong somehow, and go against hundreds of years of horological knowledge, hey you be you man... :)

Good talk.

Cheers, Al
If it runs out sooner...it had less power reserve...was my thinking.

No reason to take it so personal AL.
 

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If it runs out sooner...it had less power reserve...was my thinking.

No reason to take it so personal AL.
I don’t take things like this personally. I do my best to explain things to people, and it’s up to them to listen or not. If you don’t end up believing the facts, I personally couldn’t care less. I know that in the process of explaining it to you, others will gain a better understanding even if you can’t.

No worries on my end...
 

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I don’t take things like this personally. I do my best to explain things to people, and it’s up to them to listen or not. If you don’t end up believing the facts, I personally couldn’t care less. I know that in the process of explaining it to you, others will gain a better understanding even if you can’t.

No worries on my end...
Not a worry on my end and I still stand by the hundreds of posts that say/prove/think that if you run a chronograph the entire time your watch won't run as long.... (y)

Your even mentioned in this thread from 2013 so I see you've taken this issue serious for quite awhile. LOL

If you run it with chronograph it will stop sooner. Sure you can stop the chronograph and run it some more without but then....your not running it with the chronograph which is what we are talking about.
Maybe semantics.

 

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Not a worry on my end and I still stand by the hundreds of posts that say/prove/think that if you run a chronograph the entire time your watch won't run as long.... (y)

Your even mentioned in this thread so I see you've taken this issue serious for quite awhile. LOL

If you run it with chronograph it will stop sooner. Sure you can stop the chronograph and run it some more without but then....your not running it with the chronograph which is what we are talking about.
Maybe semantics.

Which is completely different than saying it uses the power up faster, as you have claimed. Glad we agree on this finally. ;)
 

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Which is completely different than saying it uses the power up faster, as you have claimed. Glad we agree on this finally. ;)
The watch doesn't run as long with the chronograph engaged. Yes I am glad we agreed finally.
 
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