# Regulating/adjusting Sellita SW200 COSC certified movement



## Uhrentraeger (Jul 16, 2012)

Hi there (I have been reading this forum for the past 2 years)

I have a question. Long story short:

1. I bought a Maurice Lacroix diver watch in November 2010. Silly me I bought it off ebay. The watch at that time was brand new and unworn
2. It came with a COSC certificate bearing the date 29/08/2007
3. Since day 1 the watch was running slow (about -10 to -15 seconds per day)
4. I then had a watchmaker in Edinburgh regulating it. However, it lasted only for two weeks that the watch was running say +1 seconds/day. And again it started running slower and quickly ended up running -10 seconds/day on average. 
5. Last year in July I had a watchmaker in Leicester (UK) replacing 1 hand (the original one had a blemish) and also in that case the watch came back no better than -3 seconds/day.

I think I am a bit unlucky because my movement is at the extreme side of COSC: daily average rate is -3 sec/day and all the rates in different positions are negative (e.g. 9 o'clock up -8 seconds/day, 3 o'clock up -5 seconds/day).

6. As things go the winding mechanism of the SW200 stopped working about 1.5 month ago. A local watchmaker here in Edinburgh quoted me £200-250 for the repair. I didn't commission the repair to him because he insisted it is a ETA 2824 movement and he also has never heard of COSC and £250 sounds a little steep to me.

7. I then posted the watch to an online repair watchmaker in the south of England. He charged £80 for replacing the wheels, cleaning and reassembling/servicing the movement.

8. However, the watch now is running -10 seconds/day slow again (I am wearing it 24 hours a day). He meant the Sellita is much worse than ETA (I do not doubt that) and -10 seconds/day is a good value even for a COSC certified SW200.

Now my question: it seems to me the movement is "inheritely" slow (as also testified by COSC) and making that movement run faster is impossible even after a full service (cleaning, lubricating, etc.). Right? 

I really like to know if a timing machine gives only 1 possible best case adjustment option for the watchmaker testing a movement since 3 watchmakers now have failed to bring it into the plus side.

I am tempeted to buy a cheap watch case opener off ebay. I have a dress watch with a Pesseux (hand wound) movement and my attempt to self-regulate it turned out to be successful.


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## pithy (Aug 22, 2010)

What brand and model is your timing machine?

p


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## Uhrentraeger (Jul 16, 2012)

Hi: I haven't got a timing machine. When i make reference to COSC i just repeat what my cosc certificate states:

6H (6 o'clock up): M1, M2: -4.8, -5.0
3H (3 o'clock up): M3, M4: -4.7, -4.5
9H (9 o'clock up): M5, M6: 0.1, 0.2
FH (dial down): M7, M8: -0.8, -1.2
CH (dial up): M9, M10: -4.3, -3.8
CH (dial up): M11,M12, M13: -3.8, -4.7, -3.9
6H (6 o'clock up): M13, M14: -7.5, -8.2

Variations of the daily rate: V1=0.3, V3=0.2, V5=0.1, V7=0.3, V9=0.0

Mean daily rate: -2.9 (seconds/day)
Mean variation: 0.2 (secondas/day)
Maximum variation: 0.3 (seconds/day)
Difference between flat vs. hanging positions: -0.5 (seconds/day)
Greatest difference between mean daily rate and any rate: 3.1 (seconds/day)
Rate resumption: -3.3 (seconds/day)
Variation rate per 1 degree centigrade (temperature): 0.0 (seconds/day/degree celsius)

So I am now wondering if this movement (assuming it still holds true after 5 years COSC testing date) is inherently slow. As I said wearing the watch 24 hours a day gives -10 seconds/day (after a watchmaker serviced the movement).


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## pithy (Aug 22, 2010)

Uhrentraeger said:


> Hi: I haven't got a timing machine. . . . . . . .


What is your methodology for establishing the rate?

p


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## Uhrentraeger (Jul 16, 2012)

Hi: I just wear it and compare it to a seiko quartz (e.g. every day in the morning). If it loses 10 seconds within 24 hours it has lost 10 seconds (it is as simple as that). If it would have gained 5 seconds I would not complain.


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## pithy (Aug 22, 2010)

Uhrentraeger said:


> Hi: I just wear it and compare it to a seiko quartz (e.g. every day in the morning). If it loses 10 seconds within 24 hours it has lost 10 seconds (it is as simple as that). If it would have gained 5 seconds I would not complain.


You may wish to review COSC - Contrle Officiel Suisse des Chronomtres. There is an English version.

Cosc is a static test under laboratory conditions. Deviations from these conditions result in varying rates. Watchmakers generally report instantaneous rates. Cosc is a cumulative measurement. These are very different measurements. Has your Seiko been benchmarked?

p


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## Uhrentraeger (Jul 16, 2012)

irk: benchmarked? I doubt my seiko loses 10 seconds per day (anyway valid caveat). we are not talking about comparing -1 seconds we are talking about comparing -10 seconds per day. This -10 seconds/day is also fairly constant (tomorrow it will be again -10 seconds/day). In the last 1.5 years it has never been +10 seconds/day or +5 seconds/day for that matter.

My method may not be very sophisticated but catching -10 seconds/day is not a big task to do (I do not need an atomic clock for this: I do not even need a PhD in physics for it even though I hold one and being even employed for doing research at a reputable university). I am also not after to confirm/reject the COSC measurements or bad mouth any watchmaker.

All I wanted to know: can it be regulated better or is better to just live with it.


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## pithy (Aug 22, 2010)

Uhrentraeger said:


> . . . . . All I wanted to know: can it be regulated better or is better to just live with it.


The rate of the movement can be increased by simply shortening the effective length of the hairspring vis-a-vie the gross and fine adjustments of the regulator or alternately by reducing the mass of the balance.

p


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## pithy (Aug 22, 2010)

p


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## Robb Ludwig (Aug 12, 2011)

Sounds to me like this is the difference between static testing and the real world. 

If I'm mistaken, my capability for which is renown, your watch might need to be set to run ten seconds fast, if when you wear it it's running ten seconds slow.


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## Uhrentraeger (Jul 16, 2012)

pithy said:


> p


Hi there: Thanks a lot. All I will do now: 1. Checking my Seiko quartz (as a scientist I am all for proof and refutation) against an atomic clock over the course of the next couple of days. 2. (Maybe or maybe not) Fetching a cheap watch case opener off ebay.

Anyway I think the watchmaker did an otherwise good job and I really appreciated it that he has enclosed the broken parts. The return envelope had 4 little parts which he seemingly replaced. I now learnt my lesson not to handwind an automatic. I think this has happend to my watch: TimeZone: Public Forum => Sellita 200 Movement

I was always much more worried not to overwind or break the stem on my handwound Pesseux movement in my Maurice Lacroix dress watch.


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## RonP (Jun 13, 2010)

Hi,

Sorry to hear you have so much issues in regulating the watch. In these cases (and I had it once also with a customer) the watch ran fine on the tming machine in all positions, however in the wrist it was maybe 10-15 seconds fast. I solved this by regulating the wath on the timing machine 10 seconds slow compared to how it originally regulated. After that it ran fine on the customers wrist.

Any good wathmaker n your location should be able to do this for you. Please have your watch afterwards checked on watertightness after it has been opened.

Succes,

RonP


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## pithy (Aug 22, 2010)

Uhrentraeger said:


> . . . . . I was always much more worried not to overwind or break the stem on my handwound Pesseux movement in my Maurice Lacroix dress watch.


Your Peseux (700X?) is designed to be stem wound. ETA 2824-2 Questions (Al J. = Archer)



RonP said:


> Hi, . . . .


Greetings stranger. You've been missed.

p


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## Eeeb (Jul 12, 2007)

RonP said:


> Hi,
> 
> Sorry to hear you have so much issues in regulating the watch. In these cases (and I had it once also with a customer) the watch ran fine on the tming machine in all positions, however in the wrist it was maybe 10-15 seconds fast. I solved this by regulating the wath on the timing machine 10 seconds slow compared to how it originally regulated. After that it ran fine on the customers wrist....


Old watchmaker books call this technique 'regulation to wearer'


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## RonP (Jun 13, 2010)

Eeeb said:


> Old watchmaker books call this technique 'regulation to wearer'


Indeed, but it works and makes the customer happy, so what more can wish for;-)


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## Uhrentraeger (Jul 16, 2012)

pithy said:


> p


 I now opened the case with the help of a cheap case opener.

My fine adjustment screw is at the extreme end of the "plus" marker. As I said my watch runs slow by -8 to -10 seconds/day (fairly regular).

How can I make it run faster now? I think I cannot turn the fine regulation screw further down the plus side.

Which arm do I need to turn next? The beat adjustment or gross regulation? And into the left or right side. Or does it all come down to trial and error?

I am a bit pissed off now because it seems to me the watchmaker was well aware that my movement is going too slow how would one otherwise explain the fine adjustment screw moved down to the maximum positive side?

Thanks for any input


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## pithy (Aug 22, 2010)

1. Get sufficient magnification to enable close inspection of the job

2. Source a screwdriver that fits the slot on the fine adjustment screw

3. Center the fine adjustment

4. Move the gross adjustment clockwise as observed ["north"] a very small interval with a piece of pegwood (shorter vibrating length = higher spring force = short duration half cycle)

5. Measure rate

Do not molest the beat adjustment under penalty of banishment.

p


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## Uhrentraeger (Jul 16, 2012)

pithy said:


> 1. Get sufficient magnification to enable close inspection of the job
> 
> 2. Source a screwdriver that fits the slot on the fine adjustment screw
> 
> ...


So it seems to me the Sellita movement is "up side down" in terms of plus and minus compared to the ETA?

Christopher Ward Forum • View topic - Adjusting the 2824-2 >20 sec/day

Thanks for warning me not to nudge the beat adjustment arm.


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## pithy (Aug 22, 2010)

A discussion of the post you reference is counterproductive. It is the responsibility of the reader to determine which posts are credible and similarly it is the responsibility of the writer to assure that he is accurate.

p


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## Uhrentraeger (Jul 16, 2012)

pithy said:


> A discussion of the post you reference is counterproductive. It is the responsibility of the reader to determine which posts are credible and similarly it is the responsibility of the writer to assure that he is accurate.
> 
> p


If I use your method "nudging the lever" further up north (in the original picture: up, clockwise) would make the watch going even slower. I first brought the fine regulation screw mark into the neutral position.

To make it run faster I need to move the arm anti-clockwise as shown in the thread (link above). Maybe we are cross talking und you meant by "north" denoting "anti-clockwise".

I hope I have touched the gross adjustment; I cannot see any beat adjustement lever (but I haven't got any magnifier glass).


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## pithy (Aug 22, 2010)

In the 2824 family:

Beat error is corrected (or induced) via movement of the stud holder which obviously holds the stud which is attached to one end of the hairspring. 

The effective vibrating length of the hairspring is adjusted by the movement of the regulator which holds the regulating pins which straddle the hairspring and come into contact with it in its oscillations.

The hairspring spirals clockwise from its stud attachment, through the regulating pins and around the collet on the balance staff to its attachment.

p


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## Uhrentraeger (Jul 16, 2012)

pithy said:


> In the 2824 family:
> 
> Beat error is corrected (or induced) via movement of the stud holder which obviously holds the stud which is attached to one end of the hairspring.
> 
> ...


If I am going to open it again within the next few days (it is going to fast now) I am gonna take a snapshot and post it here. It is maybe interesting to see a COSC certified Sellita SW200. As far as I can tell the balance wheel is made of Glycudur and has the peculiar cloverleaf shape.


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## pithy (Aug 22, 2010)

Uhrentraeger said:


> If I am going to open it again within the next few days (it is going to fast now) I am gonna take a snapshot and post it here. It is maybe interesting to see a COSC certified Sellita SW200. As far as I can tell the balance wheel is made of Glycudur and has the peculiar cloverleaf shape.


Which number did you move?

And in which direction, CW or CCW?

p


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## Uhrentraeger (Jul 16, 2012)

pithy said:


> Which number did you move?
> 
> And in which direction, CW or CCW?
> 
> p


I think it was 300/6 anti clockwise to make it run faster. I first moved it clockwise but it quickly turned slower.

The thing is I for the hell of my life cannot spot arm 375. There is just only one lever. I hope they are not at the same position which actually would mean I moved both arms at the same time into the same direction.

I think I need to wait until the power reserve and balance wheel stops swinging to getter a better clue.


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## pithy (Aug 22, 2010)

Uhrentraeger said:


> I think it was 300/6 anti clockwise to make it run faster. I first moved it clockwise but it quickly turned slower. The thing is I for the hell of my life cannot spot arm 375. There is just only one lever. I hope they are not at the same position which actually would mean I moved both arms at the same time into the same direction. I think I need to wait until the power reserve and balance wheel stops swinging to getter a better clue.


If you moved "300/6" CCW (topdown) - the rate would slow as the hairspring would now be "longer". The diagram above shows the layout with the autowind bridge removed. Accordingly, a portion of "300/6" may be obscured by the bridge on your watch. If you moved "375", the symetry of the beat (the comparative duration of the half cycles of the hairspring expansion and contraction) has now been altered.

p


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## Uhrentraeger (Jul 16, 2012)

pithy said:


> If you moved "300/6" CCW (topdown) - the rate would slow as the hairspring would now be "longer". The diagram above shows the layout with the autowind bridge removed. Accordingly, a portion of "300/6" may be obscured by the bridge on your watch. If you moved "375", the symetry of the beat (the comparative duration of the half cycles of the hairspring expansion and contraction) has now been altered.
> 
> p


I am going mad. I think I fiddled around with the beat adjustment lever. It seems to me the gross regulation arm is obscured. I managed to move the gross 300/6 regulation arm further down clockwise into the bridge. But there is probably now way to move it back again because it would be hard to reach it from the other side.

I flying to the continent this Saturday and my brother owns a camera; I tried to take some shots with my mobile phone but it turned out to be useless.

On another note: the beat adjustment arm has been moved now. What can I do to rectify this if at all? Or would I need to consult a watchmaker? The price for the biggest ..... of the day goes to Mr. Uhrentraeger.


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## pithy (Aug 22, 2010)

Uhrentraeger said:


> . . . . . On another note: the beat adjustment arm has been moved now. What can I do to rectify this if at all? . . . .


Buy some beer. Save some for the undergrads. Have them mobilize the university's lab equipment and catch a clean audio sample of the movement with the dial up. [For extra credit they can divide up into teams and: 1. configure a piezo mic and a mosfet preamp with a low SNR as an input for your tablet 2. write code for realtime "tick" analysis with noise filtering algorithm - ported for Android]

Manipulate the hairspring stud holder until t1 = t2 (< +/-.0005 seconds error).

p


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## vic225 (Oct 11, 2011)

I tried regulating my SW 220 with the fine tuning screw.... but seems like nothing happened.... whats the problem?


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## watchma (Jul 11, 2012)

vic225 said:


> I tried regulating my SW 220 with the fine tuning screw.... but seems like nothing happened.... whats the problem?


How much did you move it ?

and how have you checked that 'nothing happened' ?

Have you timing equipment? or have you "timed" it over 24hours or something ?

and you must have timed it for reference before any adjustment right ?


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## vic225 (Oct 11, 2011)

it was all the way to the - side before, loosing around 8 secs a day timed 24 hours with the clock on my computer, then i moved it to the middle. same rate...... but now i move around 1.5 slots to the + side seems like is finally gaining after leaving over night... will wear it longer to see whats the total for the day now...


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## LCheapo (Jul 14, 2010)

Careful with the computer clock. Those can easily lose or gain a second or two in 24 hours, and additionally they jump if/when they resync to a timeserver. Time.gov has some pages with scripts and apps that measure and compensate your round trip time. I'd recommend those.

Regarding the original thread: what ever came of that timing script that Professor Uhrentraeger was charged to create (or have his students create)?


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## vic225 (Oct 11, 2011)

checked with time.org too... weird... first day was gaining around 4, next day was losing around 6... maybe the position affects it... 1st night was crown down at night 2nd night was dial up...


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## LCheapo (Jul 14, 2010)

Happy New Year! I think what makes most sense is to invest a week without wearing the watch, wind it in the morning, record the time against time.gov, and leave it in one position until the next morning. Then repeat, working through all six positions in one week. Relatively constant temperature would also be good.

Oh, and start your own thread once you have the numbers.


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## BenchGuy (Sep 23, 2012)

Uhrentraeger...getting back to the basics of your original post:
1. Your watch can very probably be regulated to perform better than -10s/d.
2. Your COSC card is dated 2007 (although you bought "new" at a later date)...the watch has probably not been serviced since 2007.
3. Chasing regulation on a watch that is not correctly cleaned, oiled and maintained can be a real effort in frustration.

Recommendation: If you like the watch...no more "fiddling" (even if "scientific fiddling"). Take it to a competent independent watchmaker and have it serviced. Explain your interest in watchmaking and ask if you can watch and have him explain the process...you might have to pay a bit extra for lessons. This should be a lot more satisfying and less frustrating than covering new ground to you (old ground to us) on your own (albeit with well-intentioned help from the internet).

Good luck and welcome to the world of watchmaking. Regards, BG

PS: Eine Frage...sind Sie aus Deutschland gekommen?


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## Adamgreenberg (9 mo ago)

Uhrentraeger said:


> Hi: I haven't got a timing machine. When i make reference to COSC i just repeat what my cosc certificate states:
> 
> 6H (6 o'clock up): M1, M2: -4.8, -5.0
> 3H (3 o'clock up): M3, M4: -4.7, -4.5
> ...


This is normal for an sw200, but COSC certified level should do better. Your smart phone has a free atomic clock app


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