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Importance of amplitude.


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In any system, there is noise. Some random, and some systematic.

I will call the point where the balance crosses zero, in John's figure, the trip point. The faster the rate as the balance crosses the trip point the less susceptible it is to noise. So, higher amplitude (faster rate or slope) would seem to be better for at least that reason.

I am somewhat amazed at low amplitude pin lever watches that keep pretty good time.

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7 hours ago, LittleWatchShop said:

I will call the point where the balance crosses zero, in John's figure, the trip point. The faster the rate as the balance crosses the trip point the less susceptible it is to noise. So, higher amplitude (faster rate or slope) would seem to be better for at least that reason.

this almost sounds like a sine wave? a Sine wave that's affected by lift angle. lift angle becomes interesting because typically a modern watches it's really close to 52° but deal with older watches like American pocket watches then begin a much bigger span. Anywhere from 38 to 62° I've seen. Then another way you look at lift angle is the amount of time that the escapement is screwing up our sine wave. 

 

image.thumb.png.3c60b55f0d723dbd29cb3ee0d9274852.png

 

 

 

 

 

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15 hours ago, mikepilk said:

But if you have a watch that's 50, 60, 100 years old and has been used extensively, there will inevitably be wear in all components. So you cannot expect to get the amplitude the watch had when new. 

I agree that we can be a bit forgiving with very old watches. 

However, in principle, I think that a 100-year-old watch that has always been serviced well and regularly for its entire life can work like (almost) new and achieve amplitudes like (almost) new. Of course, this is rarely the case... so when it gets to us, we have to deal with the wear that has been caused by a lack of care over X years. But again, in principle, we could repair or replace the worn parts (i.e. more than a standard service, but rather some restauration). OR, we (or our client) make a decision to prioritize the originality of the watch and accept lower amplitudes.

My point is: if amplitudes are lower than the manufacturer's specification, something IS wrong -- and if our troubleshooting concludes that it's simply wear in all parts, then that's what's wrong. How we deal with that conclusion is a second question. Accept it for the sake of originality, or repair/replace. Both are fine, but that should be a conscious decision. 

I recently serviced an Omega 625 from the 1970s (=50 years old) and an Omega 244 from the 1950s (=70 years old) -- these are rather comparable movements of similar size an very similar Omega factory performance specifications. The "older" watch was clearly better taken care of in the past and I'm now getting an amplitude of 295 (fully wound, dial up). The "younger" watch was in bad shape, but by replacing 1-2 parts and a thorough service, it also runs at an amplitude of 285 (fully wound, dial up). Both comply with all the factory specifications that @JohnR725 regularly posts about Omega. This is not to brag (even though, I'm immensely proud). I'm just trying to point out that the older watch runs better than the newer one because it has always been well taken care of. And again, both run "like new" (according to the Omega specs).

Theoretically, and now I'm going very far... a very old watch could potentially run better than when originally produced because we can now use modern mainsprings and better lubricants.

But please note that I'm always comparing with the original production performance ("what they are designed for"). I'm not comparing a 100-year-old tiny ladies watch movement with a large, modern ETA movement...

 

13 hours ago, Nucejoe said:

Does this    certain amplitude     have any technical significance.

Praezis makes lots of sense here,

 

 Yet I am still not clear what makes 220 degrees majical, if I understand this part then I can easily agree amplitudes between 220 - 270 are clever to choose at the drawing board.

 

Just to clarify, when I wrote "certain amplitude" I wanted to indicate that not every watch is built for the same amplitude (270 or 300 isn't always the magic number). Ideally, we would find out the factory specifications and measure our work against that. For Omega, @JohnR725 regularly posts the specs, for example here: https://www.watchrepairtalk.com/topic/3548-omega-deville-cal-625/?do=findComment&comment=215566

When it comes to the technical significance, and apart from my point above, the other Members have posted quite some remarkable insights.

 

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Just adding my 2 cents here, and apologies if I seem to be stating the obvious, but I think the important thing is the difference in amplitude from before I touched it and after I worked on the watch, rather than an absolute number. As everyone has pointed out above there are so many variables on an old(er) watch; age, damage, moisture, service (in)frequency, under/over lubrication, wear and tare etc... that it is almost impossible to meet an ideal amplitude number. Therefore, I resign myself to being happy if I can bump up the amplitude, then I deem that I have done a good job, if there is no change or it is worse then I have to do better.

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9 minutes ago, Waggy said:

but I think the important thing is the difference in amplitude from before I touched it and after I worked on the watch, rather than an absolute number

exactly you made an improvement. Or if the watch was in really good condition with modern synthetic oils you achieve the same thing as you had before. You did not make things worse.

this is why I suggest newbies to start with a clone of a 6497 its large it's running and ideally they should have a timing machine. They verify the watch is running they taken apart they put together and verify that they haven't done a damage. Although if the pivots falloff hairspring gets mangled or other things they can blame gremlins that's quite common not their fault that any of those things happened.

29 minutes ago, Knebo said:

(or our client) make a decision to prioritize the originality of the watch and accept lower amplitudes.

the problem is amplitude is only part of the equation. Customers can't see amplitude they know if the watch is on time. They know if the watch stops after taking it off for the evening and waking up in the morning with a watch that didn't have enough energy to run overnight. But very few have timing machines amplitude isn't important to customers at all.

31 minutes ago, Knebo said:

factory specifications

factory specifications can be quite amusing if you can find them. for instance Seiko from the 4006 they give you an amplitude specification to strive for. They do not give you a minimum amplitude at the end of 24 hours?

image.png.da774f617b328ea2fe856c37a41e8322.png

typically for specifications they can be hard to find Swatch group has specifications but they're hiding behind a username and a password and account that can be really really hard to get. Which is why the best you are ever going see in this group is somebody snipping out something. unfortunately the specifications are only for newer stuff almost no vintage although Omega does have specifications for watches not covered by the specification sheet. In other words vintage but I really wouldn't call it vintage newer vintage.

let's look at the past Hamilton specifications for the 992B for instance nice PDF attached. Notice the amplitude? The way the timing is specified would be similar to how they do chronometer certification today or even in the past. Chronometer certification is based on a watch running and keeping time nobody cares about the amplitude.

But some people do Elgin internal documents 1955 approximately. Unfortunately they do not have a date anywhere in the thing it's based on his approximately 1955. You're right they are concerned about amplitude unfortunately they do not measured in degrees with the nifty timing machine and yes it had timing machine since the Al quite remember there is an internal booklet on timing machines stuff which is somewhere else

so you can see specifications but not in degrees. It also brings up an amusing problem of if you are a service the watch today with a modern mainspring versus the original weaker Elgin spring that was needed now what are you going to do?

image.thumb.png.20a85da00824c73e3c6472b8a2c706ed.png

then continuation of

image.thumb.png.39afdbfb461f9e54a8a7a251aea49ac0.png

so we can't necessarily adjust our watches beginner watch is to keep time within factory specifications if we don't have factory specifications. Here we have from 1955+ you have to convert turns to degrees which I always find confusing.

So yes amplitude is important but so is timekeeping.

 

 

Brochure_technique-SW200-1_6.pdf Hamilton 992b 950 timing.pdf

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46 minutes ago, JohnR725 said:

the problem is amplitude is only part of the equation

Yes, absolutely. But it does cover a lot.

 

46 minutes ago, JohnR725 said:

Customers can't see amplitude they know if the watch is on time.

Yes, first, this if for us as watchmakers to look at our own work. If we see that we cannot reach a certain target without replacing parts, we can talk to the customer and explain. Sure, many customers won't understand or care. 

 

46 minutes ago, JohnR725 said:

eiko from the 4006 they give you an amplitude specification to strive for. They do not give you a minimum amplitude at the end of 24 hours?

image.png.da774f617b328ea2fe856c37a41e8322.png

That's cute 😄 Well, if that's the level the movement is designed for, we should be happy with a result like that.

46 minutes ago, JohnR725 said:

let's look at the past Hamilton specifications for the 992B for instance nice PDF attached. Notice the amplitude? The way the timing is specified would be similar to how they do chronometer certification today or even in the past. Chronometer certification is based on a watch running and keeping time nobody cares about the amplitude.

But some people do Elgin internal documents 1955 approximately. Unfortunately they do not have a date anywhere in the thing it's based on his approximately 1955. You're right they are concerned about amplitude unfortunately they do not measured in degrees with the nifty timing machine and yes it had timing machine since the Al quite remember there is an internal booklet on timing machines stuff which is somewhere else

Maybe the old timing machines couldn't measure amplitude!? Maybe they'd be able to measure the daily rate, but not amplitude. That's why they base it on visual observation. But they did care about it.

Edited by Knebo
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Reducing the lock on pallet is a common technique to increase amplitude in old watches 

Good amplitude contributes to stability of oscilations?  also expands  the interval within which positional variation ought to be adjusted whilst it shifts the said interval so to includes the 220 degrees magic number. 

Is there any furthure importance in high amplitide?

 

 

 Google brings you interesting articles on accuracy versus precision, whether or not high amplitude facilitates acheiving precision is a valid question. 

Rgds

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4 hours ago, Knebo said:

Maybe the old timing machines couldn't measure amplitude!? Maybe they'd be able to measure the daily rate, but not amplitude. That's why they base it on visual observation. But they did care about it.

did you know that timing machines don't come into existence until the mid-30s? They display the results on a variety of methods but the most common was printing on paper tape that came out or printing on a rotating drum covered with paper. Elgin had several different types a machine but the drum type seems to be the most common. This is why there was the reference to measuring over a certain time span because when the drum was spinning and printing you don't see anything it's not until it stops than you can look at the pattern and see what it's doing.

We won't really see amplitude until at least the 60s and that's with analog meter. You won't see digital amplitude until the early 80s. In not going to see any specifications of amplitude until basically we have digital amplitude meters. They'll be some specifications for analog meter but that we definitely nothing for pocket watches no one can ever service a pocket watch the factory specifications because there is no specifications.

5 hours ago, Knebo said:

But they did care about it.

perhaps they did care about it but they didn't obsess about it. Quite a few people on this group obsess with amplitude is being the most important thing. Tell you what I give you piece of advice that you're not going to listen to. Something my instructor said in school and yes when we were in school no digital amplitude well not originally it came along the later on. so his saying was don't please the timing machine.

4 hours ago, Nucejoe said:

Reducing the lock on pallet is a common technique to increase amplitude in old watches 

what you're trying to say here is proper adjustment of the escapement will give you maximum amplitude. You don't want to play with the pallet stones unless you know what you're doing in other words you need to know how to adjust the escapement and that's more than just the pallet stones. This comes up with a vintage watch is a movable banking pins which are movable so watchmakers move them and playing with the pallet stones to fix that isn't really in your best interest. The overall escapement has to be adjusted correctly.

 

6 hours ago, Nucejoe said:

Google brings you interesting articles on accuracy versus precision, whether or not high amplitude facilitates acheiving precision is a valid question.

one of the problems is  accuracy versus precision is a silly  because they don't mean the same thing they have very distinct meanings. Then the discussion on this thread is amplitude which seems to be more important then if the watch can keep time or not.

For instance what would you rather have a watch that fully wound up runs at 300° and at the end of 24 hours is 201° versus a watch that runs at a mediocre 240° basically from fully wound up to the end?

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11 hours ago, Knebo said:

I agree that we can be a bit forgiving with very old watches. 

However, in principle, I think that a 100-year-old watch that has always been serviced well and regularly for its entire life can work like (almost) new and achieve amplitudes like (almost) new. Of course, this is rarely the case... so when it gets to us, we have to deal with the wear that has been caused by a lack of care over X years. But again, in principle, we could repair or replace the worn parts (i.e. more than a standard service, but rather some restauration). OR, we (or our client) make a decision to prioritize the originality of the watch and accept lower amplitudes.

My point is: if amplitudes are lower than the manufacturer's specification, something IS wrong -- and if our troubleshooting concludes that it's simply wear in all parts, then that's what's wrong. How we deal with that conclusion is a second question. Accept it for the sake of originality, or repair/replace. Both are fine, but that should be a conscious decision. 

I recently serviced an Omega 625 from the 1970s (=50 years old) and an Omega 244 from the 1950s (=70 years old) -- these are rather comparable movements of similar size an very similar Omega factory performance specifications. The "older" watch was clearly better taken care of in the past and I'm now getting an amplitude of 295 (fully wound, dial up). The "younger" watch was in bad shape, but by replacing 1-2 parts and a thorough service, it also runs at an amplitude of 285 (fully wound, dial up). Both comply with all the factory specifications that @JohnR725 regularly posts about Omega. This is not to brag (even though, I'm immensely proud). I'm just trying to point out that the older watch runs better than the newer one because it has always been well taken care of. And again, both run "like new" (according to the Omega specs).

Theoretically, and now I'm going very far... a very old watch could potentially run better than when originally produced because we can now use modern mainsprings and better lubricants.

But please note that I'm always comparing with the original production performance ("what they are designed for"). I'm not comparing a 100-year-old tiny ladies watch movement with a large, modern ETA movement...

 

Just to clarify, when I wrote "certain amplitude" I wanted to indicate that not every watch is built for the same amplitude (270 or 300 isn't always the magic number). Ideally, we would find out the factory specifications and measure our work against that. For Omega, @JohnR725 regularly posts the specs, for example here: https://www.watchrepairtalk.com/topic/3548-omega-deville-cal-625/?do=findComment&comment=215566

When it comes to the technical significance, and apart from my point above, the other Members have posted quite some remarkable insights.

 

Er what was the question again ? 🤔. Ah yes the importance of amplitude. The short answer, it is and it isn't 🙂

10 hours ago, JohnR725 said:

Although if the pivots falloff hairspring gets mangled or other things they can blame gremlins that's quite common not their fault that any of those things happened.

 😲 Oh wow pivots just fall off, on their own like ? Thats a bummer, this hobby is definitely not for me then. Anyone want to buy some watch stuff ?

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9 hours ago, JohnR725 said:

 Chronometer certification is based on a watch running and keeping time nobody cares about the amplitude.

Lets say timekeeping is the technical product watchmakers aim for and amplitude is   a measure    that indicate how well is the oscilation so is a tool useful  to our peruit of improving timekeeping.

The interval at our disposal within which adjustments are practical to make , is expanded with high amplitude , thus adjustments can be made more accurately, combined with microadjustor yet more accurate regulating is brought within reach.

 

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41 minutes ago, Nucejoe said:

Lets say timekeeping is the technical product watchmakers aim for and amplitude is   a measure    that indicate how well is the oscilation so is a tool useful  to our peruit of improving timekeeping.

I agree. Very well put!

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9 hours ago, Neverenoughwatches said:

It maybe is, but thats really a cheat way to compensate for other reasons why that movement has low amplitude instead of finding the actual reason Unless that is the actual reason. 

  We were talking loss of amplitude due to wear in used watches, nevertheless, I should have specified this technique is an option after you have eliminated all other possible causes of amp loss.

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21 hours ago, Nucejoe said:

Lets say timekeeping is the technical product watchmakers aim for and amplitude is   a measure 

what if I give up and you're right amplitude is the most important thing and with outstanding amplitude you get great timekeeping would that make you happy?

oh by the way yesterday I was thinking about the group when I was at work. Why was that the day before I had almost completed and Illinois watch made in 1888. Is all wound up running lubricated and I just left it in yesterday as when the case it up but has to on the timing machine. The nifty timing machine that does measure amplitude but also looks at the watch and six positions. So I have to please six positions on a timing machine and not please this group on amplitude.

I almost thought of bringing the print out home but I said I don't give a darn. At the end of 24 hours the balance wheel looked beautiful the amplitude in the pendant positions claim to be below 200°. That was assuming that the lift angle was correct and I just didn't feel like figuring out what should be. I was happy to set a Delta of less than 20 seconds. it was running a little something so I played with the mean time screws a little bit move the regulator and I'll see how fast or slow it's running today. But I was thinking there I was really worried about timekeeping and didn't give a darn about amplitude obviously there's something wrong with me.

Yes amplitude is important but a whole bunch of things determine the amplitude of the watch. Then depending upon things like over coil versus flat hairspring you have the regulator pins. We have isochronism wonder if that's important? It would actually be just much better for watch would keep constant amplitude versus a high to low amplitude. Because of the constant amplitude you can that much more constant timekeeping versus amplitude timekeeping variations. This is why when you look at the technical specifications of giving a maximum amplitude because anything more bad things happen. They like to see a low amplitude but that can be quite low depending upon the watch. But the silly manufacturers still want to see timekeeping.

 

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10 hours ago, Nucejoe said:

I Think I should keep the discussion going to reach a useful conclusion .

thought I would show you something that made me happy. Did I get 300° amplitude fully wound up no. At the end of 24 hours was it below 200 yes was I unhappy know what's my problem? Probably best if you don't answer that question unless your psychiatrist.

I tend to be multitasking jobs on the bench all kinds of watches in various states so is convenient to finish assembling and 18 size Illinois pocket watch made in 1888. Did the final assembly lubrication and left at the run overnight the next day when it was well and down I regulated using the mean time screws and then the regulator. Then I chased up the watch wound it back up and printed the numbers out the next day.

so we have two separate printouts one of them was at the end of 24 hours. As in see the amplitudes are nowhere near 300° how sad we will note that I'm not sad at all. I was very happy with the Delta of 14.6 seconds. Timekeeping was a fraction of a second slow I thought it looked outstanding.

Then I wind the watch up legal bit and run another timing. As we can see it still running a little slow and things I thought looked outstanding. I had also recorded what time the watch had and it looks like I lost about four seconds overnight. That is outstanding for watch those made 130 some years ago. I will probably nudge the regulator hair and speed up possibly just a tiny bit but still beyond good

then a note regarding numbers. They look impressive on the print out. But they look more impressive iPhone remember to bring the USB drive you can print everything out but the print outs art as nice as if you have a USB device you can just push the image capture and capture images off the screen. Nice when a timing machine is really running Windows CE. Yes I looked at the software update see what it was. but the note related to the numbers if I had run this several times more than likely every single time the numbers will be a little bit different. This is because of you looked at the time plot which I didn't capture for us we will see that the time plot shows fluctuations due to gear train fluctuations. Those fluctuations will average out typically over time slew not an issue usually. But the timing machine even with averaging over the Gavin set for 20 or 30 seconds there will be variations in the numbers. So for instance you put your watch on the timing machine you look at the amplitude stare at it for a while is steady or does it go up and down up-and-down there's gear train fluctuations.

So here we have an example of amplitude really wasn't that important. I'm not saying that amplitude isn't importance but an obsession with the watch most to 300° or else well I wish you well for the house if that's your golden watch repair have fun. I miss happy the watch keeps time and runs overnights it does it for a couple more days it can go away.

01 other little thing I forgot to mention. When I place a cased up pocket watch on the timing machine usually things are where the machine says they are sometimes up isn't up it's really down but the up-and-down will be up and down they just might not be the right ones. Usually the left right pendant upended down one of those are all of them will be off because I'm holding to a pocket watch case different than I would a normal movement. Even when I have the pocket watch movement in the timing machine I think the left and right are usually reversed.

image.thumb.png.31a8ed80d9af15a0895fb5522aa7f8ee.png

 

Edited by JohnR725
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46 minutes ago, Klassiker said:

JohnR275 already did?

I don't believe either the timegrapher or the watch are at fault in that case.

yes I clicked on the link I did find it amusing they do have a watch repair section and this isn't the watch repairs section. One of the complaints I have with message boards are there's too many places to hide messages and then finding them becomes impossible unless somebody points them out.

the problem with timing machines are they have limitations. All of the timing machines will have limitations if they cannot get a good clean signal. Most of the 1000 machines don't have a gain setting which can be a problem. The 1900 and most witschi machines do have volume settings regains settings but there's only so much you can do.

so if you have a heavy case possibly with a chronograph running the timing machines are going to have a really hard time getting a clean signal. I believe the person said it took more than a minute for the machine to figure out what it was seeing and that is definitely a clue to a problem. If the timing machine can't pick up that really quiet roller jewel hitting the fork then what is it picking up? Everything is dependent upon the roller jewel hitting the fork if you start picking up another part of the signal or sometimes especially if the amplitude is really low then the timing machine isn't sure where the locking occurs in other words it occurs beyond worth looking then you'll see really high amplitudes like this person is seeing when a real life it's not a high amplitude.

It's back to the reality of visually looking at the watch what does the amplitude look like. Looking at the graphical display make sure it looks clean and nice they can still be fast or slow but it has to yet the bill a recognize the lines it can't look like a snow globe as somebody else on this group likes to call it. Snow globe effect is very back. If you looked at the signals on his pictures looked at the video they looked a little on the rough side. Then of course the numbers have to agree with the graphical display and what you're seeing on the.

In real life there's probably nothing wrong with the timing machine and there's nothing wrong with the watch it's just it's not picking up a good clean signal.

let me give you a picture of the problem. This comes from the witschi machine at work as you can see from the upper and lower our oscilloscope traces there's a problem. The dashed red line is where the machine thinks it should be triggering from. The upper red line isn't quite where I think it should be but it's much closer than the lower line. Notice on the lower I oscilloscope traced it things the wrong part of the waveform is what it should trigger from. If you are looking at the numeric display or if we had a video you would see an alternating between the amplitude it shows which would be the upper one and then the other one would be much higher so you see this altering of amplitudes because of the wrong signal. So yes even a machine that cost about $10,000 can get confused. But at least with the oscilloscope I can see why it's confused.

 

image.thumb.png.2aa3d919ab2a2d07c2ae2798909b11b3.png

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