# Regulating an ETA 2892 need help



## houstontx8 (Jan 16, 2008)

Hi all,

Need help
Ok, I've read 100 plus notes on regulating watches and googled for days.

I've got an eta 2892-a2 that runs slow 4.5 seconds an hour.
It consistently looses 4.5 seconds an hour no matter how I turn the regulating screw ("A" below).

Need someone to please shed light on what I can do the the two balance arms? One is hidden under the rotor. Does anyone know what arm to move and in what direction?

Would someone please label the following drawing of what B and C do.


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## vardjuin (Feb 14, 2008)

so doe you watch go slow or fast?

the end of the hairspring is fitted to b. 
to make it go faster you should move c away from b


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## houstontx8 (Jan 16, 2008)

vardjuin said:


> so doe you watch go slow or fast?
> 
> the end of the hairspring is fitted to b.
> to make it go faster you should move c away from b


it's running slow.
So, I should not touch B and then push C away from B. (move C to the left to make it go faster). Is that correct? Thanks


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## Henry Hatem (Sep 28, 2006)

This should not be taken as a course in precision timing or an advocate of adjusting timing without the understanding of having a properly serviced movement. Also this is a "general discussion" so my assumption is the watch is serviced properly and ready for final timing. Before any timing adjustments are made a step to demagnetize is imperative or else you are chasing bunnies. Once you have a properly serviced and demagnetized movement on the timing machine, "B" in your diagram is the balance spring stud or where the balance spring is terminated. Moving "B" will alter the beat of the watch. Beat is the timing difference between the tic and toc measured in ms or milliseconds. "C" in your diagram is the regulating pins and an adjustment will alter the timing - this a "rough" adjustment. Understanding of the regulating pins and their separate proper adjustment to the balance spring along with the terminal curve of the balance spring is imperative or adjustment via "C" is meaningless an inconsistent. "A" in your diagram is a fine adjustment of timing in the seconds range. Adjusting the regulating pins distance from the balance spring stud is adjusting the effective length of the balance spring slowing or increasing the rate. The shorter the effective length of balance spring the watch will run faster. Increasing the effective length of the balance spring the watch will run slower. In contrast a "Free" sprung balance does not have regulating pins and requires a much finer grade of movement and escapement. Timing is adjusted by regulating fine weights on the balance itself. There are many details and functional checks that are made post / prior and during these adjustments that is taught in a professional or schooled environment.


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## houstontx8 (Jan 16, 2008)

Thanks!
I've updated the diagram below. I believe this matches your terminology.
Is the "B" Balance correct below, in that moving it left increases the beat?


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## Henry Hatem (Sep 28, 2006)

I would not have any "faster or slower" nomenclature on the beat adjustment. Yes you could figure faster or slower for this movement but if the balance spring is left or right hand spiral or the balance spring stud was in differing configurations this could change. Knowing this is the beat adjustment is label enough. Beat is a product of many other factors including the colleting and placement of the balance spring, the pallet fork, escapement condition etc. This can be done with a watch "run down" by adjusting the "line of centers" but the final beat adjustment of a modern watch should be done using a modern timing machine capable of displaying beat error in milliseconds, amplitude and a setting for lift angle.


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## gregoron (Feb 24, 2010)

houstontx8 said:


> Thanks!
> I've updated the diagram below. I believe this matches your terminology.
> Is the "B" Balance correct below, in that moving it left increases the beat?


Thanks for this posting, but I'm reading and re-reading this and I think this diagram is labeled wrongly - you have B and C reversed.

On the ETA 2892, B is the Regulator, and C is the Spring Stud where the balance spring ends. C changes the beat and should not be touched. Basically, do not touch the stud where the balance spring ends if you want to make time adjustments. You can make coarse adjustments via B, which is the regulator arm. Fine adjustments can be made via A.

These are my references:

http://www.eta.ch/swisslab/2892A2/2892A2.html
http://www.timezone.com/library/wglossary/wglossary631695562774064902

PS:

On the 2824 and 2842 movements, your original diagram above applies with regards to B and C.


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## lysanderxiii (Oct 4, 2006)

Nearly 2 minutes per day?

Might need more than must pushing the regulator around....


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## Genway (Feb 12, 2009)

Easy way to figure out -

When B and C are apart -> faster
B and C are closer -> slower
If spring start (attached to) from one side, move the other side only. Where the spring end is stud, no affect on timing but on performance.

Two possible problems here:
Since the regulator screw is essentrical, it is possible you turn right or left get no affect to the timing - both side came back to the same point on regulator, so need to observe closely that the regulator are actually moving when you turn.

Another possibility is the spring is not even inside of the regulating pins.

Let us know.


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## webvan (Dec 11, 2008)

A belated thank you for this topic that gave me the nerve to try to regulate my recently acquired watch with an ETA 2892 that was losing 30 seconds a day. Fine tuning wasn't going to do the job so I gave the "B stud" (not the one where the balance spring ends) and I got it to around +3 spd as per my Timegrapher set to 30 seconds, so now I can play with the fine tuning if need be.

Having said that, while doing the adjustments I saw the "beat error" as reported by my Timegrapher, vary between 1.0ms and -0.3ms so it does seem like the B stud does have some impact on the beat of the watch.


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## webvan (Dec 11, 2008)

Since I still had a beat error of 0.8ms instead of the accepted 0.3ms I went back to adjust that and gregoron was right, the "settings" are reversed on the 2892 (Omega 1120)...or rather the balance spring stud (B in the first drawing) is in fact the stud to be used to do the coarse regulation and the regulating pins stud (C) modifies the beat. On all other watches I've seen it's the contrary.

Glad I got that Timegrapher 1000 a few months if not I would certainly have "lost it" trying to regulate that SMP300. It is now ticking at +1 spd with a 0.1ms beat error. Now that the beat error is down from 0.8ms time keeping (understandably) is much more stable, it used to vary quite a bit.


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