Eta 2789-1 amplitude

[Gaus]

Hello watchlovers, I have a question. I'm servicing an eta 2789-1. When I re-install the balance balance, it runs very nice (260). But when I give the movement a little shake, the amplitude drops enorm. I took out the balanceassembly en re-installed it again. The same problem occured.  What could cause this problem? Problem end stones?

[Nucejoe]

Wiil you let us know the amplitude in at least four positions? 

Also check shakes on staff,  fork arbour and escape wheel.

I gather you didn't check the jewels hole and end stones? 

Regs

 

[Gaus]

Hello Nucejoe,

 

After re-installing the balance, it was okay in four positions. after a little shake it dropped. I took out the endstones and cleaned them.

[Nucejoe]

How about impulse and pallet stones, shelac might get washed off during clean and pallet stones move sometimes impulse jewel gets loose.

Regs 

[Gaus]

Hello Nucejoe, I found out what the problem was. I cleaned the mainplate with the balance installed, but I forgotten to clean the pivots of the balance staff. After cleaning the problem seemed to be solved.

Thank you for your advice.

with  kind regards, Hans  

[JohnR725]

2 hours ago, Gaus said:

I cleaned the mainplate with the balance installed, but I forgotten to clean the pivots of the balance staff

It also means that you have another problem? You can clean the balance wheel in the watch but you're supposed to remove the balance jewels so they can get clean. The vantage of cleaning with the balance still mounted to the main plate is it protects the balance and hairspring. But as you pointed out if you keep the balance jewels in they don't get clean the pivots and the jewels are not clean either. Not unless you take them out and clean them after the fact. So it's usually better to take the jewels out the first place they can get nice and clean with the exposed pivots also getting clean.

 

8 hours ago, Gaus said:

I took out the endstones and cleaned them.

Oh wait I didn't read everything you did take the jewels of but it's not just and some is that need the explain the hole jewel needs to get cleaned in other words the entire jewel assembly needs to be cleaned preferably without the pivot being there.