zenith

[gary17]

Hi

I am working on a zenith 2542 pc and i noticed were the balance staff goes into a jewel in the plate is mis shapen. I think the part number is 2532/3025 if i am reading the sheet correctly. Is that part called the lower incabloc?.

The pics below show number 2 the hole it came from and number 1 the jewel itself.

Is number 1 the lower incabloc and is it part number 2532/3025

Also can someone explain why there are 2 balances complete. 1 is numbered 721 and the other 721a?

Isw there any way of finding out what size the balance wheel should be as i have 2 one big no weights and one small with added weight??

cheers

gary

Edited October 7, 2021 by gary17

[watchweasol]

The part number 2532/3025  Dessous =  Underneath/lower      Dessus  =   Above so you need dessous. 

[JohnR725]

On 10/7/2021 at 12:40 PM, gary17 said:

Also can someone explain why there are 2 balances complete. 1 is numbered 721 and the other 721a?

I find sometimes it helps to have other pictures which is why we of the first two links. The second one is your watch but it's hard to see the lower jewel assembly with all the calendar stuff. If you look at the pictures the balance wheels are the same nose screws large-size exactly what you would expect to find.

The third link is the balance complete for this watch and there's only one of them. the but if you go through the parts list for your watch is a confusing mess I do have pictures of both balance wheels. Then there's another separate cross reference that somewhat confusing and not entirely clear so I'm really go with the link below of basically it's the balance wheel without screws as it looks like the first two links in the picture. As a wild guess the watch probably went through an evolution and the older balance wheel would've had screws.  or and that was the confusing thing on the cross reference sheet some of the other calibers which may be older had screws and the new one does not but that's more of a guess because typically newer balance wheels don't have screws.

 

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Zenith_2542

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Zenith_2542PC

http://cgi.julesborel.com/cgi-bin/matcgi2?ref=[^[DXMSI

 

 

 

[anilv]

No 2 is not the hole it came from. The jewel setting needs to go in the hole where the end of the pallet fork is. Its pretty obvious from the dial side, I guess you've misidentified the hole when you flipped it over.

Anilv

[anilv]

wrt to the two part numbers..the 721 seems to be a screwed balanced and the 721a is probably a newer design with better material (elinvar etc) for temp compensation. You will probably find the earlier balances more difficult to source but the 721a should fit fine.

Anilv