Eta 2824 shows poor amplitude after service.

[Gaus]

Hello watchlovers, I have service my eta 2824 movment (with date). I tested it on the timegrapher. The beat error is oke (0.1), but the amplitude is very low, about 170. Is there something I did wrong? Thank you in advance for the help. Sincerely, Hans

[jdm]

Can you post a timegrapher picture, that may give an hint. A common cause is the hairspring touching somewhere. Sometime that can be revealed by listening or looking at the waveform, but the primary inspection is always visual.

[watchweasol]

As mentioned by jdm a picture of the timegrapher display and of the watch, and also what you did by the way of service. :- example   change mainspring, balance end stones and shocks removed  etc, all will go towards a possible diagnosis.  Thank you

[Tudor]

And make sure the lift angle is set correctly. (53 degrees for the 2824 and 50 degrees for the 2824-2)

[Gaus]

Thank you very much all. The problem was a very tiny piece of debris under the balance, as jdm suggested. Problem solved.

[jdm]

1 hour ago, Tudor said:

And make sure the lift angle is set correctly. (53 degrees for the 2824 and 50 degrees for the 2824-2)

That only changes the amplitude reading of less than 5 deg. No matter the caliber, when the amplitude is way off,  don't blame that to the instrument left at its very adequate default of 52.

[Tudor]

All I’m suggesting is that we control what we can, with the greatest accuracy possible, to better understand the things we cannot control. 

[jdm]

6 hours ago, Tudor said:

All I’m suggesting is that we control what we can, with the greatest accuracy possible, to better understand the things we cannot control.  

All I did, if you allow me, was to provide a factual bit of information to guide not only the the OP, but any beginner when it comes to diagnosing low amplitude. 

Now for the technical explanation. Below the amplitude calculation as provided by JohnR275 in the relevant topic further below.

In the example if we  replace the lift angle with the correct value of 50° for a 2824-2, we get 221°, to correct an error of about 9°. Which is significant perhaps for fine adjusting, but not in cases of severely degraded amplitude. 

 

[Tudor]

Informative post!