Girard-Perregaux Caliber 03B

[noirrac1j]

Hello fine watch fellows! It’s been a while since I’ve posted mostly because school is giving me a thorough thrashing and I simply don’t have time to do much of anything else. Well, recently I overhauled a Girard-Perregaux manual winder with caliber 03B. I was impressed by the quality of the watch and I have not been able to date it with certainty except that it has sub seconds, and to me that means late 50’s but I’m not sure.  

 

The watch had been roughly treated in past as evidenced by the scars on the movement, but it is well made, and is now at least being better cared for.

 

 

In any case, the overhaul was performed carefully and everything went back together without incident. The timegrapher helped me get it within a few + seconds a day and all seemed well…After letting it sit overnight I noticed it was running 20 minutes slow, and so I thought I must have set it wrong (which has happened after a long night!) so I set it again and checked it after an hour—20 minutes slow! I found it strange that it would run so consistently slow, so if course I put it back on the timegrapher and tweaked it to run about 20 seconds fast a day and again reset the time. When I checked it again one hour later it was 20 minutes slow.

 

OK, so I knew something was wrong, but what? It was not the balance or the drive gears because the timegrapher readings are good, but I noticed the hands were very easy to set—almost no resistance. I remember reading about certain cannon pinion problems and so I suspected that. After some research I knew it had to be the cannon pinion because the time loss was too consistent and rapid to be something in the gear train. Also the timegrapher readings were good—but that loose action upon setting was a hallmark of a loose cannon pinion.  I didn’t want to try a nail clipper (yes, I guess some people have used these) because this is not my watch and replacement parts for this GP caliber are non-existent—I checked everywhere.

 

So I went ahead and bought a cannon pinion tightener from Dash To and nervously went about it.

 

 

 

 

It took two taps and…. Success! cannon pinion tight! The Girard Perregaux keeping time beautifully again (after readjusting, of course).

I posted just in case anyone unfamiliar with old[er] watches comes across one losing big chunks of time, especially after an overhaul--check the cannon pinion!

 

J

[Geo]

Lovely watch you have there Joe, and a good write up that will help someone down the line! :)

[cdjswiss]

Congratulations on a very fine restoration and great sleuthing re. the slipping cannon pinion. I have used the same cannon pinion tool with disastrous results. I think that you had just the right touch. A too-hard tap with the hammer and I was left with two half-cannon-pinions!

 

I have since learned that it is advisable to insert a taper pin before tightening

 

 

Also, a safer tool is the inexpensive Bergeon 31001.

 

 

I am now awaiting delivery from Cousins before tightening the cannon pinion in the photo.

 

 

[Geo]

Definitely a good idea to insert a mandrel for support. The one Joe has just tightened looks like it is blanked at the hand end.

[WillFly]

Great watch - and a lovely demo of the job in hand!

[cdjswiss]

Definitely a good idea to insert a mandrel for support. The one Joe has just tightened looks like it is blanked at the hand end.

 

Yes, Geo, on looking closely I an see the blind end. The only reference that I have found to dealing with this type of cannon pinion is in the beginner's book by Harold. C. Kelley. He suggests the obvious which is to shorten a tapered broach or pin so that it fits into the Cannon pinion with some friction.

 

I also like the treatise by Jeff Elgin who goes into this business in some detail.

http://elgintime.blogspot.ch/2012/01/mechanics-of-canon-pinion-friction.html

[noirrac1j]

Hello,

 

Thanks for the feedback.  One of my big fears was damaging or crushing the cannon pinion, and I do have some cutting broaches that are tapered. This cannon pinion was very a small diameter and closed off on one end so I could not pass a broach through it. I took my chances, yes, and also used a gentle tap. The first one didn't do much, so I turned the cannon pinion around and also tapped the other side and that did the trick. The watch works beautifully but I still can't find any references to earlier GP watches by year, caliber or anything substantive (beyond the SeaHawk model). Does anyone know of some write-up or link on older GP watches? Thanks again!

 

 

P.S. That Jeff Elgin write up was what I read as a reference!

 

J

Edited May 9, 2015 by noirrac1j

[Geo]

I use a modified set of end cutters to tighten cannon pinions. The screw allows you to increase the compression a little at a time until the correct amount of friction is achieved.

[clockwatcher]

Joe, that's a peach of a watch - a juicy one! Just oozing quality.

[bobm12]

Just ordered the Bergeon tool from cousinsuk as recommended by Colin! Thanks, Colin!

 

On the other hand, that is a beautiful quality watch Joe! Great job.

 

Cheers,

 

Bob

[noirrac1j]

Thanks Bob!

 

J

[Gary]

Great write up and thank you for sharing!

[noirrac1j]

You're welcomed! Thanks for all the feedback.

 

J