WatchTech

My question is regarding different grades of the same caliber, for example the Eta 2824-2.

Hi Jon,
Looking at the technical documents from ETA of the 2824-2 there are differences between the 4 different grades.  Some have only to do with the finishing, some with the testing and regulation and some are different materials.  In my opinion it is only the differences in materials that will influence the timing. 

The 4 different grades of the 2824-2 are: 1 Standard, 2) Elaboré, 3) Top, 4) Chronomètre

Let us ignore the differences that exist in decoration and talk only about those that might have to do with the timing.
According to the documentation the grades fall in 2 groups according to the materials used.
The differences between Standard and Elaboré in one group and Top and Chronomètre in the other group have to do with the regulation and testing.  It looks like every Standard could be regulated as well as an Elaboré and every Top as well as a Chronomètre.  One would just have to spend the time to do it.

The materials differences are:
  Grade                                                     1) 2)                                      3) 4)
  - Mainspring material                          Nivarox NO                         Nivarox NZ
  - Pallet material                                    polycrystaline ruby            ruby
  - Balance wheel material                   nickel                                   glucydur
  - Hairspring material                           Nivarox 2                             Anachron
  - Shock absorber system                   Etachocs                             Incablock

At least for this movement I don't see anything that would suggest that the Chronometer version is less robust than the others.

Don


This message has been edited by DonCorson on 2013-11-10 05:51:38

This is very interesting information.  It does, however, make me wonder all the more why some rather high-end brands use the lower grade movement, if they're not more robust, and the cost differences between the grades is fairly low compared to the total price of the watch.

Hi Don, thank you for your inputs: me too I’m interested in the differences between the various grades of the ETA movements. In particular, for the watch I’ve designed I’ve chosen the ETA 2892A2 for its reliability and robustness, but also because of the availability of technical documents on the ETA website (essential, to design the whole watch). I’d like to have a watch with a good accuracy and I’d really appreciate a movement with COSC performances, so I’d requested to my watchmaker to search for a “Top” or a “Chronomètre” version, but I guess it's not so easy…

That said, let’s go to the point. The watch I’ve designed has a solid case back, therefore I’m not interested in special finishings, except if they’re intended to give the movement substantial improvements in reliability and/or robustness and/or precision. The ETA 2892A2 is used by many watch companies and I’m aware of the following improvements: increased winding efficiency by reducing the diameter of the ball bearing support and application of rhodium plate on the main plate, bridges and plates for a better corrosion resistance. Could you confirm? Could you add some more suggestions?

Thank you in advance!

Ciao,

 

Elio

Hi Elio,

As you may be aware ETA has removed the manufacturers information from the public portion of their website recently.
Because of this I am not able to look into more detail on the 2892A2.
In small quantities the only movements that are available are those destined for service work.
Chronometer movements should be available, but will be very expensive I think.
If you are able to become a direct customer of any movement manufacturer, certain quantities of movements a year required , they will make the decoration as you would like it.  You can choose.
As the winding efficiency of the 2892A2 has always been somewhat in question, I can believe that they have made improvements in this direction.  I am not aware of anything in particular 'though.

 I wish you all the best for your project.  Be sure to keep us informed as it advances.
Don

Dear Don, thank you for your kind, friendly and very competent reply.

I wasn't aware ETA has removed the manufacturers information from the public portion of their website. This means that the files I've downloaded when I started to design my dream-watch, are "precious", in some way. The version of "Manufacturing Information" in my possession is the one released on the 24th February 2011; about the available grades of the ETA 2892A2, it gives the following technical description:

My project advances quite slowly, but it's not my fault. To better explain my design ideas, I've became in a few months a self-educated 3-D programmer on the 3-D modeler Rhinoceros. To realize a plastic prototype, I've learned to work on meshes and on Stereolithography format. To facilitate the production of the various parts of the watch, I've became in a few months a sort of technical drawings designer. Now, if I want to dress my "creature", I have to go through the patience of a Zen monk: you know, very reasonably it's not easy to speak with watchmakers, casemakers & various suppliers when you're ordering a pièce unique...

Ciao,

 

Elio