Logines Pocket Watch - Yoke Spring Problem Caliber 19.75

[Tschacko]

Hey guys,

I wanted to service a 100 year old Longines Pocket watch. As soon as a removed the dial the yoke spring sprung out of place. There is a wheel holding it also in place (see second picture)

Anybody can help me put it in the right place ? I thought it was enganged in the hole with shorter end but it seems to me it would be too twisted.

Thanks Tschacko

[matabog]

open the spring more!

 

http://ranfft.de/cgi-bin/bidfun-db.cgi?1k&ranfft&143&2uswk&Longines_19_75

 

[HSL]

It seems to be very deformed so be very careful when correcting that arc on the yoke spring.
If you have a small vice try to tap it rounder again, bending it with a deformation like that will probably make it snap .
 

[anilv]

It doesn't look like an original spring to me, probably he original was lost and someone modified another to fit.

Guitar wire is a good source of springy metal wire.

Anilv

[AndyHull]

I agree, that looks like entirely the wrong spring, unless someone has already messed up the curve, in which case, it is probably not going to be reliable anyway. I would suggest replacing it.

Another source of sprung wire are the springs in old ballpoint pens, which came in a variety of wire gauges.

Metal musical instrument strings (guitar, violin etc) are typically made of steel, often over-wound with nickel. Save the nickel for your electroplating experiments.

You can of course purchase spring wire (brass or steel) by the reel,  from the usual suspects.

You may need to remove the temper, bend the wire to shape and re-temper it. This is a bit of an art in itself. I'm not sure this is the best video on the subject, but it is certainly one of the most entertaining.

 

 

Edited March 5, 2019 by AndyHull

[Tschacko]

Looking at the picture of Ranfft.de it seems like the original spring (if it is still original) also does not do a nice curve.

Good to know. I am an guitar player so I could use my old strings maybe. The thin 3 upper springs are not wound with Nickel so I could use them maybe.

I think I will try bending the old one and see how it goes.