Job Number 190195, Elgin Grade 437

This project is Elgin's grade 437, 12 size, 17 jewels, made about 1914.

The job begins with a pretty obviously broken mainspring.

This grade of Elgin is less common, and it has some unusual features. It’s thinner than other 12 size Elgin movements for one thing. One of the ways this is achieved is to use a thinner barrel and to mount it lower. Note the large round cut out in the base plate. The mainspring barrel arbor on this movement is not supported by the plate.

To accommodate the mainspring barrel cut out, the minute wheel is offset and an intermediary gear added. The minute wheel clamp is virtually identical on millions of Elgin 12 size movements of nearly all grades, but on this grade it is different.

There’s a few different tools around for manipulating hairsprings, and different ones are good in different contexts. On larger springs when adjusting the height of the stud, as I did on this watch, the wide tweezers pictured here are just right. The short, wide nose can securely grip the outer coil and hold it straight, while using the other hand and regular 3C tweezers to change the bend with a slight twist.

The ratchet wheel and mainspring barrel have an unusual design, for Elgin.

Here is the dial side of this movement. Note how the mainspring barrel comes all the way down through the base plate.

Project link (all the posts): https://pluspora.com/tags/190195_et

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And the album for this project is here: 

https://photos.app.goo.gl/TpjUJ5BMR4PRmwtp9