Patek “Model 10” Service info

[Woolshire]

I have several 1900-1930 Patek wristwatches (only one is complete with case/dial/hands). All are 10L (round 22mm’ish), and I believe were referred to as “Model 10”

I have asked a few general questions on here (thank you for the helpful answers!) and feel I’m ready to completely service these watches BUT I find it interesting that there are, basically, zero guides or videos of these watches being serviced. I also know parts are really hard to find. I’m sure I can find a mainspring that will work, by measuring the old one, but a new Patek mainspring would be a nice touch.

Has anyone seen a service manual for these or videos of watchmakers working on them? I’m guessing the rarity of these and the absence of willingness (by some) to share repair techniques on these rather expensive watches is the main reason finding service info is difficult.

Photo is one of the earliest. It needs a balance stud cover and the pallet and bridge...tall order, I know. The pallet was the mustache type.   

Any service info or helpful tips appreciated.

[nickelsilver]

You won't find any tech guides on these, they figured anyone working on them would know where to put some grease and where to put some oil. Parts were somewhat available 20-25 years ago depending on caliber, but usually needed final fitting requiring at a minimum a lathe and rounding up tool for wheels, and quite likely faceplate work for bridges. Patek won't supply parts anymore and there's about 0% chance anyone has a stock outside of them. Your best bet if finding a donor movement, but that's not so easy and there's still the fitting thing- these were made in rough form in large batches, then finished in small batches of 5 or so at a time. Some things might interchange but it's never a given.

 

The only thing out of the norm you might encounter with this movement is the ratchet wheel should fit on a square integral with the barrel arbor, and the barrel arbor should be in two parts, with the square and a large shoulder on the outside, then the hook will screw on to it from the inside, making the barrel captive.

[Woolshire]

Thanks for the response. I’m not sure I followed the barrel arbor two-piece part. I will be careful taking it apart. The Geneva stop works is also something I hadn’t encountered before. I since have worked on a couple that have that. 

Does the mainspring on these have normal ends? I mean like most other Swiss watches from this period?
I would love to find a pallet and bridge for this one, but doubt there are any available out there...at least for a non-obscene price . I see a few pallets for Patek out there, but zero mustache style. 

[Woolshire]

Well, no time like the present. I decided I would tear down the watch. Here is the barrel. I removed the stop works. The wolfs tooth winding wheel is still attached. I’m assuming that unscrews from the arbor. I hold the square of the arbor and then unscrew the winding wheel? A little help here, please?

Also, you can see the mainspring is broken, but does appear to be a “standard” style.

[nickelsilver]

The ratchet should lift off, then hold the square and use your special 2 pronged tool to uncrew the hook* and it all comes apart. These would typically have a hole end spring with either an attached or separate "t" that fits in a slot in the barrel and one of the notches in the lid. A normal tongue end replacement will work fine with the barrel hook.

 

* I Usually grab the square, the with a firm grip on parallel jaw pliers, not on the hook itself, unscrew the "bonde" (hook part in French). It's usually not that tight.

[Woolshire]

Okay, thanks!

 The ratchet wheel doesn’t want to pry off. Obviously, I’m not going to force anything. The trick is sometimes figuring out what “force” really means.

btw, if anybody is interested, the mainspring on this is 1.50x0.09x11.75”

[Woolshire]

Hmmm...The wolfs tooth ratchet ain’t budging. I tried to unscrew the bottom of arbor, but that isn’t moving, either.

I have used as much force as I’m willing to, without better understanding how this comes apart. It should be normal threads, right? Doesn’t seem it would be reverse threaded, but thinking through that makes my head hurt.

There is a square hole in the ratchet wheel. It seems that if that is held, I should be able to unscrew the bottom of the arbor via the two holes. That isn’t working. I did notice that the later model has a round hole in the ratchet wheel. I’m guessing that one would lift off and I could proceed as described earlier. This one seems to have the ratchet wheel actually screwed onto the arbor, or otherwise attached.

Any further advice?