Playing watchmakers

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Thanks again Al!

Actually, I have this tool - I do not know the English name, "tour à pivoter" in French. But I do not have the part used to hold it and I still have to learn how to use it...
 
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Great - it's known as a Jacot tool. I actually just got the vise for it last week so I can now relocate it to be at my bench. Just FYI the vise is a Bergeon BG 2101 that has the slide lock, so there's only a plate mounted to the bench, and you can just flip a lever on the vise and remove it any time you want. Right now I just have it screwed to the bench top, but once I use this for a while and check the location to make sure it's good, I would set the plate into the bench top using a router...

As for how to use it, that's more difficult to answer. You need to know how to make/dress a burnisher, then how to select the right sizes for the pivots, and then learn how to use the tool - a bit like patting your head and rubbing your stomach at the same time, so it takes some getting used to. I believe George Daniels "Watchmaking" has some information in it on the use of the Jacot, so if you have a copy I would look there for a start. I'm sure there are other books but I can't say for sure right now.

Cheers, Al
 
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Hi Francois

You're certainly trying things out. I'm not sure that everyone has success initially with balance staff fitting so, seems pretty good going especially that you are managing to problem solve. It is difficult to use the right amount of force as sometimes you really do need to use what seems a lot and other times virtually nothing.

I think, in addition to what Al says, that Dr Carle also has a section on using the Jacot tool, if that helps. His book is pretty old and can read a little out of date but, it's another good book to have, "Practical Watch Repairing" and is also available on Kindle.

I like your comment about getting a microscope next.👍 It is surprising what you miss without one and how it can make your life easier. I think my instructors comment at the BHI was, "nowadays, you're no-one if you don't have a microscope as everyone expects one". I use mine all the time.

Keep it up.

Regards, Chris
 
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Thank you for your comments Chris!

I have to aknowledge that the microscope project is mainly due to Al and you! Obviously I will say it is your fault to my wife when she will see that strange thing on my desk...
 
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Hello,

I have been palying with watches again lately, so I thought I could talk a little bit about some service. I have also practiced changing staff, with rather "good" and so so good results, but that will be for another post.

First, let me introduce you the new visage of one of the watches I have talked about here, my Omega 30T2 in 18K solid gold. I eventually found a dial from the correct size and decided to replace the "original" but redone dial. I switched the hands as well:


As I still was not happy with the timegrapher results, I took the occasion to change some worn parts and service the watch again. I changed the 3th and the 4th wheels, the former with a used one in better condition and the latter with a new old stock one. I wanted to change the 2th wheel as well as it has straches (yes!), but I could not find one that could engage correctly with the barrel - and I did not want to change the barrel as it would have ended in a new watch! By the way, I realised at that occasion that the cal 30 have (at least) two kinds of teeth for the barrel and the second wheel.

As a result, the amplitude get better and more regular - even if it is still not perfect, maybe due to the 2th wheel issue. So now I guess I am happy with this watch!


Second, I would like to talk about two other solid gold cal 30 - I like this stuff! I serviced them those last few days and could use the kind advices I received here. It is also a good example of the difference between a worn movement and a movement in a very good condition.

First, I got this Dennison cased 283. Quite a big size with its 3,6 cm but I like it nevertheless - I am rather a 32-35 guy!



I have serviced other watches for the last post of this thread - I barely spend a week without servicing a watch! But this time I had plenty ot time and decided to do the very best I could.

Well, there was not much to do! I was only very careful in everything I did, in particular when oiling. I remembered Chris' advice about the oiling of the mainspring: I already did like he adviced me - oiling the entire mainspring before putting it into the barrel instead of adding three points of oil when it is in the barrel - but thanks to him I have understood better the importance of doing that. Same thing with the oiling of the pallets - thanks Al this time!

I only had to correct the hairspring as it was out of shape. But I only had to touch the overcoil, so it was not too difficult. I kept the mainspring I found in the watch because it was like new.

The timegrapher results are very good, but there were at some point an issue... Excellent amplitude, even too good! Around 340 at full wind in dial up and dial down positions! I thought the mainspring could be too strong, but eventually I think it is something else - will talk about that in a few sec. Good delta over 6 positions (25 sec) without doing any dynamic posing. I could have slightly reduced it (25 sec between 3up and 9up, so I could simply have added some weight at 9), but that wasOK for me.

But I had an irregular line in some position. I mean : the line was perfectly straight, but the "points" were not "clean". I thought it could be because of the pallets. So I cleaned the pallets and the pallets bridge again, but it did not change anything. I tried to change the pallets with a used one in good condition. It changed the amplitude - back to 270 dial up and down - but not my issue. I have to say that at this point the movement was in the case.

What puzzled me was the fact that the first try of the movement on the timegrapher was very good... So I thought the issue could be due to the case. After some head scracthing I eventually found the issue:





I had not srewed tigh enough the 2 screws holding the movement into the case! Usually, I screw those tigh like the other screws, but this time not...

So now, the timegrapher results are good, with the bigger amplitude I have ever seen on a 30 cal: 340-350 dial up and down at full wind - without any rebanking, which surprised me - and 310-315 in the vertical positions.

Now I have some questions for Al, Chris and the other experts.

i) First, I would have thought a watch would rebank with a 350 amplitude. Is it strange? Maybe my cheap timegrapher does not give me the exact amplitude...

ii) Second, I know (in theory!) that the "achevage" (I do not know the English term) - the precise settings of the pallets in their relation to the escape wheel and the balance - is important and can have an effect on the amplitude. But I was suprised to see that my 340 amplitude with the current pallets became a 270 amplitude with another ancor. Is that normal?

I have changed pallets stones and corrected them in order to have a decent relation with the escape wheel. But I have not done any real "achevage" and I am reall surprise to see this difference of amplitude.


Second, a 284 in a French case. This watch came with the original band and a rare French made Omega buckle - see here: https://omegaforums.net/threads/about-omega-buckles.37347/page-5


The service was badically like the previous one -and I kept the mainspring as well. I only had to slightly correct the hairspring: it was actually very good but a little bit out of center. I had also to correct the end shakse of the barrel, vertical and horizontal. I am not sure wether the bushing of the barrel bridge had been redone during a former service. But the bushing was a little bit to low and to tigh. Solved thanks to the staking tool, a file and an "equarissoire" - I think there are better tools but I did with what I have!

This time, the results were very good, maybe the best ones I have ever had:

Full wing + 30 min
pos rate ampl beat error
DU 6 309 0.4
DD 6 304 0.4
6up -4 272 0.4
9up -2 272 0.4
3up -3 279 0.6

Delta over 6 pos : 10

Full wind+ 24h
DU 5 300 0.5
DD 7 292 0.5
6up -4 266 0.5
9up -2 267 0.3
3up - 9 267 0.7
12h -4 271 0.6

Delta over 6 pos: 13

Please, note that I am fully aware that these results are due to the movement condition! I barely did anything to get that. Well, I think I have done my best, but obviously the movement was in a very good condition. It is really nice to see a 30 cal in its best! What a difference with my 30t2!

Thanks for reading this, and thanks for any constructive criticisms and advices you may have!
 
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Now I have some questions for Al, Chris and the other experts.

i) First, I would have thought a watch would rebank with a 350 amplitude. Is it strange? Maybe my cheap timegrapher does not give me the exact amplitude...

ii) Second, I know (in theory!) that the "achevage" (I do not know the English term) - the precise settings of the pallets in their relation to the escape wheel and the balance - is important and can have an effect on the amplitude. But I was suprised to see that my 340 amplitude with the current pallets became a 270 amplitude with another ancor. Is that normal?

Hi François,

1 - What was the lift angle on the timing machine set to? If it was set correctly, then yes I would expect that at 350 degrees you would see rebanking, but each watch is different in the amplitude required for this to occur. Some watches start rebanking as low at 310 degrees, and others I've had at 340+ before they started. I can't say I can recall one being at 350 and not rebanking when the lift angle was set correctly.

But also keep in mind that the amplitude displayed is an average (average of the amplitude in each direction) and it's also a calculated, rather than a directly measured, value. It may very well be that the machine doesn't calculate amplitude in the exact same way as some others might, so the value may be artificially high for example. In a watchmaker group I belong to there was recently a rather long debate over the accuracy of the cheaper machines, and some evidence was presented that lead me to question how accurate they really are for professional use.

2 - The adjustment of the depth of the pallet fork stones can have a huge impact on amplitude. Adjusting the depth is a fairly advanced thing to do when done accurately. There are still many who use a pallet warmer over a flame and eyeball the adjustment, but for me there is really only one way:





Both the amount the stone is adjusted and the fact that they produce the same amplitude of the balance is fairly critical to good performance.

Nice results by the way.

Cheers, Al
 
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Thank you Al!

The timegrapher was set to 49, so I think it is OK. To be accurate, 350 is the max the timegrapher showed - in DD position. It is more often 340. But what you said about cheap timegraphers and how the amplitude is calculated could give the explanation.

Nice tool you have here! I must aknowledge I use - when I do, that is to say pretty rarely - "a pallet warmer over a flame and eyeball the adjustment"! And it is only to have the pallet fork work, not for precise adjustments. I think it is far too advanced for me - currently at least!
 
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Hard to say for sure why it wasn't rebanking, but when it does it's pretty obvious so I think you were lucky there. If you aren't seeing the effects in timing, it must be okay. Can I ask if you have the sweep seconds pinion installed yet when you saw this? Just so you know when I have a watch that has an indirectly driven sweep hand, I typically perform my initial timing and amplitude checks without that installed. Since the tension on the friction spring can cause such a difference in amplitude, doing it without that installed initially gives me a more consistent feel from one watch to another for how the watch is performing - it removes one rather influential variable. Once I know it's all good without the sweep seconds pinion and friction spring installed, I then install them and check it again, watching for excessive amplitude drop. Just something you may want to consider doing if it makes sense to you.

For adjusting the stones, I wasn't meaning to sound derogatory - people use what they have and what they know. I would not expect you to go out and spend $1000 on a new escapement meter (plus a heater) for the rare instance you might need to adjust the pallet stones, so using the pallet warmer is the only reasonable option for you at this point. Even I don't adjust pallet stones that often, so it's only a few times a year I have to drag it out and burn my fingers...mine doesn't have the same level of insulation that the newest meters do, so my fingers are always a bit sore after using mine. 😀

I took a course specifically on the use of this meter and how small changes can affect how the watch runs. Using a timing machine with a scope function allows you to see the amplitude of the balance in each direction, and when we moved a stone we could see the effect of that. You could dial in the amplitude to within a few degrees by moving stones, and getting them to both be the same was important. It was an eye opener for sure, but again not something people do a lot of typically, depending on the type of work you do...

Cheers, Al
 
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Thanks Al!

No trouble at all, I understood you were trying to help, as usual! Maybe I was not clear enough when I quoted you - I was not at all suggesting you were making fun of people.

I think I have already heard you giving that advice concerning movements with an indirect sweep second. Actually, I have tried to follow that method. I tested the movement over 6 positions before installing the sweep pinion. But I could have probably done a more complete test - I only checked a few seconds, the day of the first part of the service and the day after, and continued by installing the pinion. The amplitude did not drop too much I think - say, 10 sec.

The results I gave above are with everyting installed, including the hands, a few days after the service. I guess I got lucky!

I have checked again after your last message, now the amplitude at full wind + 10 minutes is 342 DU and 348 DD - with a measurement over 30 seconds.
 
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By the way, if I have the opportunity, I will check this watch on a better timegrapher. I would be interested to know if the measurements I have with my Chinese timegrapher are correct, in particular with this kind of amplitude.
 
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So, I have been spending a part of my hollydays to try again changing staffs. Pretty funny, but not easy!

I have tried a few weeks ago to change two staffs for two JLC 480 I have. Well it did not end well! Changing an Omega 30 staff, as I have first tried to do, is much more easy that to change a staff on those small balances!

Actually, my first attempt was not too bad. Before I changed the staff, the balance worked a while but without being at all true. It appears that the staff was no longer strongly fitted to the balance. I only had to touch it a little bit to get it off... But thanks to that issue, I had not to cut it off, which is currently the part I fear most.
I ended with a balance that could work. But the balance was not very true, and I wanted something better. So I tried to correct that. Well, it ended with a brocken staff and a dammaged balance!

Then I tried to change another staff on the second 480 balance. This time, I had to cut off the old balance. I used again the little tool I have talked about earlier in this thread. Tricky to use correctly! As I wanted to avoid touching the balance with the abrasive wheel, I stopped before the part of the staff I had to remove were completly cut away. But thus it remains too strongly attached to the balance, and when I tried to remove it thanks to the staking tool, the hole of the balance got dammaged. I could next fit the new staff, but could not get a balance true enough to be used...

I was not so happy, and thought (I still do!) changing this kind of staff was too avanced for me at that point. It would be better for me to practice with bigger and tronger balances as the Omega 30 ones.

But I already ordered staffs for another JLC... A non working Memovox I bought cheap as I wanted to see inside! This Memovox has a 489 caliber, the first Memovox caliber as far as I know. The alarm was not working and the main movement could work but with many issues.

To sum up, with this movement I had to:
- fix the alarm, which I could do without changing part - with a lot of head stratching!
- change the sweep pinion, one of the 3th wheel jewel, and one of the winding clutch. I also had to change the time mainspring, which is not easy to find!
- as the balance staff was dammaged (twisted), I eventualy had to change it. That was the funny part...

I had bought a donor movement (with a brocken staff) for parts - as the sweep pinion alone is worth 90 euros, it was my best option! So I had two balances, and I bought 3 staffs.

With the first attemps, the same story that with my first JLC 480 happened. Not so bad at first, but not perfect, then very bad! I do not want to talk of the second one - sad story! With the second balance and the third staff, I tried a last time before accepting the idea that I would have to find an expansive donor movement with a good balance...

This third attempt did not start well, as I touched the balance with my staff removing tool. At that point, I think I have to find another solution, but I do not own a leath - I think I am not advanced enough for that - and the Platax tool, which seem a good option to me, is way too expansive if I only change a couple of staff every six months.

But I thought I could give this balance a try. So I fitted the last new staff. The balance was not perfelecty true, but it was not so bad. So I decided to continue, and poised it. Actually, I stopped too early as I can see now with the timegrapher I have a poise error. Once the balance complete has been put together, I put it back on the movement. Well, it is ticking right now! And the timegrapher results are not TOO bad. I cannot consider it works well - amplitude too weak and for the moment a pretty huge delta over 6 positions. But I can live with this amplitude and I can improve the delta with some (dynamic) poising.

So not bad after all! I just have to find a sweep second hand.

By the way, I am not fully sure of the lift angle of that movement. I read on the Internet that it is 40, but that sounds a bit low - even if I know old movements such as JLC's and Longines' can have low lift angles. Does anyone know it for sure?

 
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Actually, the watch is rebanking dial down, though the timegrapher says it has only an amplitude of 240. So I guess the lift angle is rather 56, like the 814 and the 815, which are improvements of the 489.

Will see what to do with the rebanking. With the lift angle set on 56, I have currently 305 DU at (almost) full wind, and 325 DD. So I have a difference too big between DU and DD. I will check the flatness of the hairspring tomorrow and maybe the balance jewels movement side. But at least I do not have a low amplitude, and the balance is doing its job!

By the way, having a rebanking issue with a genuine old stock mainspring already happened to me with an Omega 26,5. I wonder if those blue steel mainsprings do not get more strengh through time. Any opinion about that?
 
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Blued steel springs tend to get set and lose their strength, rather than gain any. Have you confirmed the lift angle by observing the balance amplitude at 180 visually, then adjusting the timing machine to match?
 
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Hello everybody,

It has been a while I have not added news to this thread, even if I have been playing around quite a lot...

So back to the JLC 489 "Memovox"! I was not completely happy with the balance with the new staff, and I still had to find a second hand. So I bought another donor movement in order to get the parts. The seller was not clear about the balance, and I hoped it was good. It was not! So I thought I could try to fit a new staff...

The balance of this new donor was in good condition - except the staff - so I decided to keep this one. I am still not confortable with the first part of the job, that is to say removing the old staff. I have bought a "K and D" remover, and it was the first time I used it.



It is supposed to hold the balance when you break the staff rivet in the staking tool. Well, I did not find it is so great... At least for small and fine balances such as the JLC 489 one, I am not sure it holds well enough the balance. But everything ended well this time!

The next step was to fit the new staff. My hammer hits have probably been a bit strong, but I am getting more used to this operation. When I tested it, the balance appaears not to be true enough, so I had to give new small hits in order to improve it. I am not completely happy with the result, as the balance is not perfelcty true. But I hoped it could be good enough, so I continued: I poised the balance and put back together the balance complete.

Next was the time for the timegrapher tests! Actually, it is not so bad. I have straight lines, a decent amplitude (around 280°/230° at full wind plus 30 minutes), a small and rather stable beat error (between 0 and 0. ) and a decent delta over 5 positions (24). It is not perfect, but it is good enough for me! The 12 up position is not good (slower than the other positions), but even if I prefer to regulate everything over 6 positions, this time I will be happy with 5 positions - at least for the moment!

By the way, I had to change several other parts in this watch: obviously the two mainsprings - which are not easy to find at a decent price! -, the second wheel, the cannon pinion (oddly it was too long for the second wheels I found on donors), the second hand, and one of the sliding pinions. I had to buy two donor movements, which were not cheap! So I guess it is not the cheapest Memovox you could find, even if the original watch was not expansive. But it was a great project! And I have learned quite a lot...

François