# ETA 2836-2 vs ETA 2836-2 COSC



## Guest

Hi all..

I understand my Engineer Master II Diver using calibre ETA 2836-2 while
Trainmaster Cleveland Espress is calibre ETA2836-2 with COSC certification.

Does this mean both watches are using the same calibre, albeit one is with a COSC certification ?

If I am not wrong, COSC only a shown of verification that the watch has been subjected and passed a series of test (among them the -4/+6 sec daily rate spec). The test itself does not make the watch more accurate.

If that is so, does it also mean both watches will have the same accuracy ? 

As I am new to automatic movement, I am presuming that accuracy of the movement mainly depends of calibre. Am I right in this sense ?

Hope any kind soul in this forum can able to enlighten me. 
Thanks in advance.


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## obie

Yes and no. 

Within a single movement group, i.e. ETA 2836-2, there are different levels of ebauches, i.e. unfinished movements. Some ebauches are more expensive than other versions within the same group, as sometimes there can be numerous versions of the movement depending on the fit and finish of the ebauhes. 

For your question, these are in fact two different ebauches, with one difference. The COSC movements come to Ball Watch already tested and certified by the COSC, as in the one used in the Cleveland Express. This means that the movement was sent to COSC and run through their multiple tests. The ones that pass get the cert and are sent back to ETA/Ball. There is a cost to test, and that is usually passed on to the end user. 

The movement used in the Engineer Master II Diver is not COSC, but is still a high caliber ebauche of the ETA 2836. The movement could be COSC certified if sent to COSC, but it is not so the cost is not as expensive since it wasn't individually certified. 

So within the two watches you mentioned, yes they should keep time the same. Understand that there are numerous lower grades of the ETA 2836-2 which are not finished as well, and could give less accurate timing. Ball watch from what I was told uses either COSC certified of COSC certifiable movements. 

What makes one version of a certain caliber better than another is the parts used within the ebauche and the time taken to make sure all the parts work as they should, i.e. individual time putting the movement together and "tuning" them if you will. So there are many factors that go into what will make a movement or watch run better than another.

Now the movements are tested for COSC not the entire watch. Additionally most companies finish their own movements to make them unique to them. Rotors are usually added by the company and are blued screws or finishing on the actual movement. I own two COSC watches, and about 6-8 non-COSC, and thankfully most of my watches all keep time within COSC specs. But even a lower caliber movement given to a competent watchmaker, should be able to get close to COSC standards easily.


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## sukispop

Excellent explanation, Warren! :-!

Thank you!


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## Guest

Thanks Warren.

Appreciate your great effort in explaining to me. Thanks again.

Cheers..


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## avaxis

obie said:


> Yes and no.
> 
> Within a single movement group, i.e. ETA 2836-2, there are different levels of ebauches, i.e. unfinished movements. Some ebauches are more expensive than other versions within the same group, as sometimes there can be numerous versions of the movement depending on the fit and finish of the ebauhes.
> 
> For your question, these are in fact two different ebauches, with one difference. The COSC movements come to Ball Watch already tested and certified by the COSC, as in the one used in the Cleveland Express. This means that the movement was sent to COSC and run through their multiple tests. The ones that pass get the cert and are sent back to ETA/Ball. There is a cost to test, and that is usually passed on to the end user.
> 
> The movement used in the Engineer Master II Diver is not COSC, but is still a high caliber ebauche of the ETA 2836. The movement could be COSC certified if sent to COSC, but it is not so the cost is not as expensive since it wasn't individually certified.
> 
> So within the two watches you mentioned, yes they should keep time the same. Understand that there are numerous lower grades of the ETA 2836-2 which are not finished as well, and could give less accurate timing. Ball watch from what I was told uses either COSC certified of COSC certifiable movements.
> 
> What makes one version of a certain caliber better than another is the parts used within the ebauche and the time taken to make sure all the parts work as they should, i.e. individual time putting the movement together and "tuning" them if you will. So there are many factors that go into what will make a movement or watch run better than another.
> 
> Now the movements are tested for COSC not the entire watch. Additionally most companies finish their own movements to make them unique to them. Rotors are usually added by the company and are blued screws or finishing on the actual movement. I own two COSC watches, and about 6-8 non-COSC, and thankfully most of my watches all keep time within COSC specs. But even a lower caliber movement given to a competent watchmaker, should be able to get close to COSC standards easily.


do we know for sure Ball buys ebauche, or complete movements from ETA and stick it in the watch? i've tried searching information on Ball watch movements and to be honest, very little information was available.. seems that nobody is aware.

"accuracy under adverse conditions".. i really love to know what did Ball do to the movements to live up to that statement in terms of accuracy. i just came across this article about how bell & ross slaps complete movements from ETA straight into the watches..which got me thinking about Ball

P/S i know some people don't really care about movements, well, I do. I won't be too happy knowing that the heart of my Ball watch is the exact same thing in the Tissot (completed movement from ETA and stuck in the watch - not that Tissot is bad, its just a difference class and price range).


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## v76

If you want your mind to rest easy on the movement, buy from a true "manufacture" like Zenith, Girard-Perregaux, JLC or Rolex ... or, a Grand Seiko??


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## avaxis

v76 said:


> If you want your mind to rest easy on the movement, buy from a true "manufacture" like Zenith, Girard-Perregaux, JLC or Rolex ... or, a Grand Seiko??


or a Tissot? Since Swatch group owns ETA AND Tissot, it is effectively an in-house movement. Same goes with Orient and Seiko. all Orients and Seikos have in house movement. so to speak.

in-house movement is not what I'm after. just want to know what did Ball do to live up to "accuracy under adverse conditions". the adverse conditions part I know, the Hydrocarbon line lives up to that. so I am asking about accuracy now... from the looks of it nobody here has a clue (yes I did search).


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