Beginner's pocket watch - 1925 Elgin Grade 315

[jmarcott86]

So I decided I wanted to learn how to fix watches, as one does, and after many nights browsing eBay I decided to jump in and buy this beautiful little watch. It wasn't running at all when I got it, and the keyless works were all stuck and it wasn't moving the hands when the crown was pulled out. I disassembled and cleaned everything, and even bought a microscope to try servicing the balance jewels (almost losing a screw or two in the process). The crystal is in very good condition, and the dial is nearly pristine, and cleaned up very nicely with a bit of distilled water and a microfiber swab.

After a couple of weekends troubleshooting piece by piece I got everything running, and after lubricating everything it's running well and keeping very good time. The time grapher app I'm using on my PC suggests it's running +/- 5 seconds with around 290 degrees amplitude, but the beat error is pretty bad at around 4 ms. I tried adjusting that too, but when I took the balance off and inspected the hairspring under the scope I noticed a partial fracture of the hairspring collet! I found a donor movement for $12 though, so hopefully it has a good hairspring I can swap in 

[JohnR725]

27 minutes ago, jmarcott86 said:

I noticed a partial fracture of the hairspring collet!

Unfortunately all too common on pocket watches in which case it's best to leave it alone.

28 minutes ago, jmarcott86 said:

I found a donor movement for $12 though, so hopefully it has a good hairspring I can swap in 

As you're new here just a reminder swapping hairsprings usually leads to timing issues. Typically on modern watches you cannot swap the hairspring as each hairspring is vibrated to that exact balance wheel. In the case of the Elgin watch You can swap the hairspring but You will have to match the balance wheel to the hairspring. In other words  there will be some timing adjustment issues.

I would try to swap the entire balance wheel and who knows you might be lucky and it might just swap but probably won't.

29 minutes ago, jmarcott86 said:

PC suggests it's running +/- 5 seconds with around 290 degrees amplitude, but the beat error is pretty bad at around 4 ms.

Your PC is suggesting excellent timing wonderful amplitude and why do we care about the beat now? Of course there is the problem of how does the watch really run over 24 hours versus the timing. Plus I assume you looked at the timing and more than one position? But it's back to is it worth trying to fix the beat error?

 

[watchweasol]

Hi  John is absolutly right in what he says  some times its a case if it not broke then dont fix it, its a nice looking watch and running well enough for its age. well done for getting it working again.

[jmarcott86]

That totally makes sense that the balance and spring go together. As long as it runs well I could probably live with the beat error. I just have to give it a bit of a twist to get it running. It's not consistent in all positions (about +/- 60 seconds stem up/down, but I'm not sure it was even when it was new since it's an unadjusted movement.

I'll probably just keep the donor movement as a spare in case the collet on this one ever completely breaks.