A Seiko shows strange behavior

[UhrTobi]

Hello,

I'm new here since a views hours and there is already my first problem I'm not able to solve. I did my first practice on a Seiko 7S26C movement. It is from a watch of a verry good friend. He was verry unsatisfied with its performance and told me, that the watch goes some times to fast, other times to slow. A timegrapher analytics shows this, too. In the same orientation the watch fluctuates between ca. +25s/day and -30s/day within a view minutes without any disturbance from outside. It had got a verry low amplitude of about 156°. He gave it to me just to practice. But now I have a strong motivation to fix the problem. I dissassembled it following Marks verry helpfull videos on youtube, cleaned and lubricated it and put it together two times. It still works nevertheless . And the amplitude is now sometimes over 200° but suddenly it goes back to 180°. I could regulated the beat error down to ca. 0.1ms and it goes to max. 0.6ms depending on orientation. But the amplitude is still not stable and the accuracy is still fluctuating. The hair spring looks good ans all bearings seems to be clean. And so I can't guess, what the problem is. I would be verry glad if someone could give me some assotiations how I could fix the problem.

Many thanks an best regards

Tobi

[Nucejoe]

If you find a patern in fluctuations,  you have spotted where the fault is likely to be. 

 

[UhrTobi]

Thank you! I did never measure long enough to see any pattern. I will do so now and will report

[watchweasol]

Have you demagnetised the watch as magnatism can cause fluctuations.

[UhrTobi]

Oh, no I don't - I have got not such a tool. I guess, I will need one. Good idea! Thanks 

[UhrTobi]

Here in my laboratory, there is a magnetometer with a high resolution. I will take the movement tomorrow and do some measurments.

[JohnR725]

2 hours ago, UhrTobi said:

A timegrapher analytics

I don't suppose we could have pictures of this? In addition to a picture of like dial down perhaps crown down would be nice? Sometimes we can see things that look fine do you but don't want find us.

 

2 hours ago, UhrTobi said:

But the amplitude is still not stable

Until you can get the amplitudes stable everything else will be unstable. Seiko watches will run with lower amplitudes but they have to have stable amplitude as long as that's unstable everything else is bad so you have to deal with this.

2 hours ago, UhrTobi said:

I'm new here since a views hours and there is already my first problem I'm not able to solve. I did my first practice on a Seiko 7S26C movement. It is from a watch of a verry good friend. He was verry unsatisfied

Then just to clarify something is this the first watch you've ever serviced?

[UhrTobi]

Yes, it is my verry first . I think, I will learn much about all this, if I can find the reason for the behaviour with your suggestions . I will take some fotos of the screen this eavening in all orientations and I will measure the magnetic condition of the movement - thank you. 

[JohnR725]

1 hour ago, UhrTobi said:

I did never measure long enough to see any pattern.

Depending upon how your timing the watch a problem with LCD-based timing machines is it's hard to see long-term patterns. Your fluctuations Are slow enough that their back quite a ways in the gear train. Somewhere you're having as a  a power transmission issue As a guess.

This is where typically when you're assembling the watch you get the basics of the watch running and you put it on your timing machine. But it looks like you finish the watch and gave it back to the owner and then discovered your problem? So it's better to find out if you have a problem before the watch is entirely assembled. It makes it easier to troubleshoot if you don't have the entire watch their.

 

[UhrTobi]

Quote

Depending upon how your timing the watch a problem with LCD-based timing machines is it's hard to see long-term patterns.

Yes, that is a problem.

Quote

But it looks like you finish the watch and gave it back to the owner...

No, the movement is still out of its housing and waits for some new ideas. The watch comes to me with this problems and the owner did not expect me to find a solution. He gave it to me just for my practice. But I will give it back to him until I managed to fix the problem - that's how I intend to do it .

[JohnR725]

2 minutes ago, UhrTobi said:

The watch comes to me with this problems and the owner did not expect me to find a solution.

One of things always nice is to tell us stuff like that in the beginning in other words the watch had this problem. Because often times people repairing watches especially new people repairing watches generate new problems.

Then you also discovered cleaning doesn't fix everything.

3 hours ago, Nucejoe said:

If you find a patern in fluctuations,

See if you can find a pattern having a pattern watch repair really helps. Except sometimes it's really hard to find.

What did you do with the mainspring barrel when you were servicing the watch?

3 hours ago, UhrTobi said:

And so I can't guess, what the problem is.

The problem is this is watch repair? Currently were guessing because we need proper eyes in the field with proper observation skills usually lacking in beginners.

In addition to this problem in the watch came in any other things you observed? Rust on the stem or the watch looked super dirty any other observations incoming?

[jdm]

3 hours ago, UhrTobi said:

.And the amplitude is now sometimes over 200° but suddenly it goes back to 180°.

On this class os Seiko you need a bare minimum if 210 deg. constant and steady in all position. Also, lines must be straight and without off dots. 

Unfortunately when that dies not happen it becomes very difficult to achieve for a beginner. The hairspring may look OK to you, but it no, including on the vertical plane. Same for pivots and escapement, or endplay it could be also that the train is not absolutely free. Then you will be told about a weak mainspring, but tou would be wastunf time and money trying to replace it. One thing is sure, magnetizaton does not cause limited amplitude. 

All that being said, it's to you to decide if accept that is like that, otherwise be prepared to for frustration while chasing gremlins that cannot even be seen. 

[UhrTobi]

Quote

One of things always nice is to tell us stuff like that in the beginning in other words the watch had this problem. Because often times people repairing watches especially new people repairing watches generate new problems....

Oh, I thohgt I did - excuse me. Yes, I'm a beginner and my goal was at first not to solve any problems but to dissassemble and reassemble the watch. I never thougt, I would get by so that would be on live after this torture, but it did and it did a little better - a verry liitle from 156° to samewhat between 180° and 200°. Still verry low, I know. And now my goal is to fix the problem. If the watch would die over alls this, it is not such worse, because my friend gave it to me just for practice. He told me, he would be glad if it could be fixed. But when not, never mind... So I have no risk and I will take this to learn. Thats the complete background. Of course I would be a little proud of setting it to work again, but when not, did I learned a lot anyway. My eyes are very good. I did a lot of little things in the past such as soldering FPGA MCUs etc. and there I've got several verry good microscopes, stereoscopic fom 1x to 3x and a view classic ones from 4x up to 1000x (I know, that would be not necessary) . So I think my equipment is verry sufficient. 

The movement was verry clean. Somewhere there was a little to much oil so I cleant it but there was no rust or dirt anyway.

Quote

Unfortunately when that dies not happen it becomes very difficult to achieve for a beginner. The hairspring may look OK to you, but it no, including on the vertical plane. ...

For me it is just a challange. If I will be not successfull, there waits o lot of old watches on wich I can  continue practicing. I will not be frustrated, don't worry. But I'm still highly motivated to fix the problem. I can not find any deformation on hair spring on any axis - I examined it from all sides with the stereo microskop, but of cource, it could be, that I do not recognize a deformation wicht the expert woud see at once   .

And in this minute I did a measurment with my smartphone (Catapilla62) using phyphox and I found a magnetification roughly about 10µT - could this be enough to cause problems?

[UhrTobi]

I forgot: I cleaned the main spring to and brought it back to its barrel  - I hope, I did it not such bad

[JohnR725]

2 hours ago, UhrTobi said:

And now my goal is to fix the problem.

That is a good Goal let's continue with this. As you're beginning to grasp that we would usually prefer beginners start a little differently there's other movements better to learn on etc. etc. but were here now you have a watch let's find out why this watch is it running and what if anything you can do to fix the problem? At least you didn't start on a Rolex watch or Omega watch or Basically expensive watches where it's very problematic to obtain spare parts and a happy outcome is usually not guaranteed.

9 hours ago, UhrTobi said:

Seiko 7S26C

Then I hate to assume things like you have the tech sheet? In case you don't I'm attaching one.

Then I'm looking for something specific But on looking at it I'm stepping out at least one image. Notice someday will have to meet somebody from a Seiko and ask them a technical question like Whitey oil the pallet fork pivots? Because in general the world feels this is evil and bad and don't do it. So as you're new to watch repair you might follow the technical guide this is where you do not fall the guide do not boil the pivots the pallet fork. You do have to oil the pallet stones Where they engage the escape wheel

One of the trends that was the watch companies are doing today is the mainspring barrel notice in the tech sheet it says barrel complete? This is because most companies today in fact most companies in the service centers will just replace the entire barrel. That's because are interested in doing things really really fast or service centers and they can get barrel complete switch we cannot conveniently. This means the tech sheet doesn't tell you how to taken apart it didn't explain how to lubricated and didn't explain all the things you need to look at like is the barrel worn out?

Then one of the problems with the Seiko tech sheet is that it doesn't tell us something action doesn't tell us a whole bunch of things like honey wine this watch up? Or what sort of timekeeping can you expect so how do curiosity rather than me telling you how exactly did you wind the watch up before you put on the timing machine?

 

Seiko 7S26C_36C.pdf

[UhrTobi]

Quote

Then I hate to assume things like you have the tech sheet? In case you don't I'm attaching one.

Wow, thank you!!

Quote

At least you didn't start on a Rolex watch or Omega watch or Basically expensive watches where it's very problematic to obtain spare parts and a happy outcome is usually not guaranteed.

Oh yes, starting whith a Rolex it would be a little too brave, I beleve. I've got a new Mühle-Glashütte watch. In fife years it shoult have a service the manual told me. So I have got 5 years to learn. I hobe I will manage that

Quote

You do have to oil the pallet stones Where they engage the escape wheel

Ok, good to know! Thank you, I will do so 

Quote

This means the tech sheet doesn't tell you how to taken apart it didn't explain how to lubricated and didn't explain all the things you need to look at like is the barrel worn out?

It was not such complicate to open the barrel and extract the spring. It was a little dirty but the inner surfaces of the barrel looks fine after cleanig. I oiled it following Marks videos - I can only hope, I did a sufficient work. 

Quote

Or what sort of timekeeping can you expect so how do curiosity rather than me telling you how exactly did you wind the watch up before you put on the timing machine?

I winded the wheel above the barrel to winde up the main spring more than ten times and it still runs since the eavening before yesterday.

 

This eavening I do some measurments with the timegrapher and several positions of the movement. For each position I took two scrennshots with ca. 1 minute between each. I font sometimes some dots outside the main line so could this be noise from some disturbing element?

[xyzzy]

One thing to check, you have pressed the crown in all the way, so the watch is not in time setting mode?  If you leave it engaged then the keyless works can cause a decrease in amplitude that comes and goes and you get something like what you see.

[UhrTobi]

Quote

One thing to check, you have pressed the crown in all the way, so the watch is not in time setting mode?  If you leave it engaged then the keyless works can cause a decrease in amplitude that comes and goes and you get something like what you see.

That is right, but is this not the normal use position of the crown? 

[jdm]

2 hours ago, UhrTobi said:

That is right, but is this not the normal use position of the crown? 

Of course it is. Since this mov.t does not hack, it may happen that the stem is left unnoticed in the setting position. However from your pictures that does not seem to be the case.

One of the most common reasons of reduce amplitude is the hairspring rubbing on the balance arm, it's almost impossible to detect that visually, so the best way is listening carefully, some people even looks at the waveform, but that requires  adapter for the timegrapher microphone to plug into the PC.

[Nucejoe]

 In cases where reduction of amplitude is accompanied by gaining time, your prime suspect would be a fault at  hairspring,  rubbing, sticking....  etc, out of best oscilator also eats amplitude but wont affect accuracy ( it will affect precision however) , but if its just low amplitude and timing is good, other causes come to picture, like bad jewels or pivots, pallets ..... that eat amplitude. 

JohnR's  point is real important to keep in mind, "  at low amplitude tg readings are not credible " 

 

 

 

[UhrTobi]

Quote

One of the most common reasons of reduce amplitude is the hairspring rubbing on the balance arm, it's almost impossible to detect that visually, so the best way is listening carefully, some people even looks at the waveform, but that requires  adapter for the timegrapher microphone to plug into the PC.

I see - I have to work on a spectrum analyzer  . Thats not impossible. I will try to manage this (could last a view days ). Thanks for this tip! 

Quote

JohnR's  point is real important to keep in mind, "  at low amplitude tg readings are not credible " 

So maybe if I get the amplitude at a reasonable value, the measurments will show a higher stability.

[JohnR725]

4 hours ago, UhrTobi said:

I see - I have to work on a spectrum analyzer  . Thats not impossible. I will try to manage this (could last a view days

You don't need a spectrum analyzer?  Here's a question the ask everyone that's helping you today ask how many of us have a spectrum analyzer?

I suppose if you would like to spend your way out of a problem I could recommend some nice witschi timing machines. Like in our oscilloscope features really nice. We have that of work I really like that you can look at the waveform see if there's other noise in the waveform. Time plot is nice really nice and let you look for power fluctuations in the gear train which you might be having here. For automatic microphone that is really really nice. What's not nice is the insanely high price of well it's really expensive fortunately at that work.

Now you get stuck with something different? How does watch repair compared to being a doctor? Ever notice how doctors say they're practicing well watchmakers are practicing. Every single watch we touches like a patient and their all the moonlit different. So why am I bringing this up? How do we learned watch repair how doctors learn. Usually hobbyists don't quite learn like doctors do sort of? In other words ideally you should possibly go to school study read books do lessons gain knowledge practice on dead bodies. In watch repair then you move into a Chinese clone of a 6497 running you get a live patient preferably with your timing machine. Verify it's running it has heart beat before you  play with it taken apart put it back together make sure it still running like it was before. Or we just grab a patient jump in and start practicing like were doing here which is a problem.

I'm too lazy to read everything above so I was asked some questions like why exactly were you given the watch in the first place? Yes I know it wasn't running and it was a dead on arrival and it's not expected to reroute leave to running condition but worked on change that we expected to leave running. Why did the customer think the watch had a problem? Did you put it on the timing machine in the beginning before you started playing with it? What I'm trying to figure out is what existed before versus what have you done to the watch? Because in trying to figure out a for chasing two separate problems the original problem and whatever new problems you have or whether it's all the same thing war I don't know?

A lot a good help up above?  so you can understand why the answer I originally had here is gone and you get all of this? I was looking at the answers related to the hairspring? Yes it's really hard to see if it's touching the balance. It's usually easier to see if it's flat user hairspring flat. It's not flat it introduces problems. If it's touching the balance arm it's definitely a problem. Sometimes it's extremely difficult to see if it's touching the balance arm. What I will do but if you do what I do you break anything don't blame me. I will gently push down on the hairspring over a balance arm and see if they hairspring goes down at all in other words is it resting on the arm or is floating above the. But depending upon the size of the hairspring how soft it is you have to be extremely careful or you have a new problem. Sometimes you get the lighting right to shadowing right.

So was thinking about hairsprings then your timing machine images they have a problem it's a big mess? What I mean by big mess well I think most of us know dial-up and dial down and crown up down whatever but you made it one big image and the contrasting is a little hard on the display so I enhanced little the photographs because we have a problem?

You notice I'm not really concerned about the graphical display is more concerned about the numbers? Dial-up and dial down should always be very close to identical. If for amplitude socks both of them should suck equally. Going to the crown positions are the pendant positions with a pocket watch is more friction amplitude will always go down. But we have an interesting problem here dial up as 191 that looks promising. 197 looks better and the other image. But what about dial down  172 and 174 dropped a little bit? What about the crown position why is that equal to the dial position that shouldn't be at all.

When we start dealing with too many problems you have to go back to the basics. Like and others have mentioned this the balance jewels did you know that the  end stone on the end one sides flat and one side is slightly curved what would happen if you put those upside down? I'm making a wild guess but we're having a problem here definitely having a problem with the balance wheel unless and that's problem?

So while you think about all that I had another question what you grease your mainspring barrel with?

So we need the before and your before analysis of what you perceive the problem was and if you had before timing how does it compare to after. Are we trying to fix a pre-existing condition which we still haven't figured out or the new problem that you may or may not of introduced. Then you really don't need a spectrum analyzer if you won the lottery a really expensive witschi machine would be nice but you still have to grasp what you're looking at and which are looking at in the watch fancy timing machine doesn't make for a good watchmaker.

[jdm]

9 minutes ago, JohnR725 said:

 how many of us have a spectrum analyzer?

Potentially anyone owning a decent computer, using free or commercial software, maybe in trial mode.

I never used one on a watch however it would be certainly interesting for academic speculation or research. Certainly not needed or canonical for practical repair. 

[JohnR725]

2 hours ago, jdm said:

I never used one on a watch however it would be certainly interesting for academic speculation or research.

Somebody's already done the research in 2007. I have a nice PDF that I downloaded and has been uploaded at least twice to the message board somewhere in the middle of the DIY timing machine I know I uploaded it and somebody recently uploaded it again. I'm not going to post in this discussion because I think somebody needs to learn how to analyze and troubleshoot their watch. But you can do a search it's on the other discussion that should be titled Signature Analysis of Mechanical Watch Movements.  Is an interesting paper because it gives you a clue as to what frequencies you need and don't need. Which is why the preamp that I have I don't look at anything below 1000 cycles and it works fine.

 

[UhrTobi]

Dear John,

 

many thanks for your helpfull words! I will answer to the main things and I'm verry enthuseastic to do so .

First I measured the watch with a timegrapher (Weishi) before I started. The amplitude fluctuated near by 156° and there was a beat error of ca. 6 ms.  After I had dissassembled and reassebled the movement (and also cleaned and oiled it!) the amplitude becoms a little higher - between rohghly 180° and 200° - sometimes lower.  I think, the measurments shows a still erratic condition.  The beat error I could reduce to someting about 0,2ms and it is quite stable.

I've got a view books and after reading them I do not beleve, that I'm realy able to fix problems but I felt, I could make a first tiny step on this movement, my friend gave to me eaven for my practice and not for fixing any problems. But suddenly the movement survived after twice disasseblings and works a verry little better than before after cleaning ans oiling. I never thought, that could hapened and now it is a chalange for me to learn and to fix this problem. But because I have no experience before I hope to find some help here and I'm thrilled a bit that you all gave me so much suggestions to fix it. So it will surely last a view days to try ans examine all this. And by the way, as a physicist building a spectrumanalzer is just an other challange, too. But this is not the main thing. Lets go back to the movement it selfe. Most of you sugest that the problem has something to do with the balance. I was able to buy two other balance-units on ebay. So I will change the original. Maybe something new will happen 

 

Quote

Signature Analysis of Mechanical Watch Movements...

Thanks for the tip. I will look for that document 

[LittleWatchShop]

5 hours ago, JohnR725 said:

Here's a question the ask everyone that's helping you today ask how many of us have a spectrum analyzer?

I can generate an FFT on my scope...so there is at least ONE!!  LOL

But...I don't.

Edited January 12 by LittleWatchShop