Mainspring issue...humbled

[LittleWatchShop]

Pride goeth before destruction and a haughty spirit before a fall--Been a little prideful about my watchmaking progress but was humbled yesterday when I broke a mainspring.  Did not know they could be so delicate.

Anyway, now I am learning about mainsprings.

This is a Wittnauer C11KS movement.  Jules Borel site is very useful for confirming my measurements on their database, but they do not stock the part I need.  So, I go to Ofrei.com and find a generic.  Here are the specifics:

W: 1.1mm, T: 0.1mm, L: ~15"

I did the calculations for length using the formula in the Bestfit catalog and it is close.

So right now, I think I will get the mainspring on the Ofrei site unless someone else has a better idea (sourcing the part in US).

 

[JohnR725]

always nice when getting a mainspring to measure whatever was in the watch to compare to whatever you think is supposed to be in the watch

then I'm having a confusion second length I believe is for your watch it does give the specifications for the mainspring which seems to be different than what you have above? Then the last two links appear to have the mainspring

MS-38T   MAINSPRING 1.20-.14-400 12   GR 3004

which do not agree with the numbers you have above so I'm confused?

 

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Wittnauer_C11KS

http://cgi.julesborel.com/cgi-bin/matcgi2?ref=WIT_C11KS

http://cgi.julesborel.com/cgi-bin/matcgi2?ref=qWH_h

https://www.jewelerssupplies.com/product10262.html

http://www.ofrei.com/page1834.html

 

 

 

 

[LittleWatchShop]

Here are the measurements of the barrel.

Total barrel thickness: 1.59mm

Barrel lid thickness: 0.21mm

Bottom of the barrel (LOL) thickness: 0.19mm

Space for the mainspring: 1.59 - 0.21 - 0.19 = 1.19 mm (prolly 1.2mm)

I have attached images of the measurements.

You can see that I measure 1.1mm for the width of what came out.

I found a C11K mainspring on ebay today...ordered it.  Something will work.

I watched Mark's video on this topic this morning.  I would like to get my hands on that GR handbook (or pdf). 

[LittleWatchShop]

Note that there is a lip on the MS barrel lid.  I did not measure it, so it could reasonably be 0.1mm thus requiring the MS to be that much thinner.

[LittleWatchShop]

23 minutes ago, LittleWatchShop said:

I would like to get my hands on that GR handbook (or pdf).

They are on Cousins website...10 pages at a time.  I downloaded them all and combined them into one PDF file.

 

[jdm]

41 minutes ago, LittleWatchShop said:

They are on Cousins website...10 pages at a time.  I downloaded them all and combined them into one PDF file.

Full catalog available at https://watchguy.co.uk/tmp/GeneraleRessorts.pdf and hereby attached, 1974 edition. One wonders what they did in the last 46 years about documenting their products ?!?

The Cousins UK copy had the advantage of carrying many annotation to expand applicability and correct errors.

BTW, that JFA micrometer is the bomb.

 

GeneraleRessorts.pdf

[LittleWatchShop]

Just now, jdm said:

BTW, that JFA micrometer is the bomb

Yup...I love it.  Another great inheritance from my Dad.

[LittleWatchShop]

This is what arrived from ebay purchase and installed today.  Seems to be working properly.