johnswatch1
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Part four - the wheel train
Now on to the wheel train.
The 12"'120 movement is beautiful in that it allows you to see the full transmission of power from the barrel (first wheel) through the centre wheel, third wheel, fourth wheel then to the escape wheel and balance.
Notice the little drilled hole in the centre wheel. This is done at the factory to separate components into tolerance groups. From the barrel to the fourth wheel, all wheels have a single hole, so that wheels from the same tolerance group are used together. Normally, these are just scratch marks, but here, we have another sign of pure class. Perfectly drilled holes (rather sinks, as they don’t go through). Great stuff.
Note also the polished sink around the centre of the wheel, the bevelled edges of the spoke arms and the perfect tooth formation.
Even the barrel lid has perlage decoration. Something is odd about the mainspring looking through the lower opening in the lid.
This is pretty shocking … and I know why the impulse pin is knocking the bankings! The mainspring must have broken at one point, and, instead of replacing it, somebody shortened it by one or two turns and bent it back on itself and wedged a piece of broken spring into that bend to form the end that locks it in the barrel. The shortened mainspring will produce too much torque, and the running time of the movement is a lot lower. On top of that, the guy used wheel grease or something similar on the mainspring.
Someone has marked the movement number into the barrel. This suggests that the movement has been separated from the barrel, e.g. to have the barrel wall reconditioned.
And finally, the bare plate
Beautiful mix of perlage and Cote de Geneve decoration on the top plate.
Here's a closeup looking at the different finishes
These are decorations that nobody except the manufacturer and a service watchmaker would ever see. It's an incredible amount of detail with no real functional benefit. Absolutely stunning. This is where precision engineering meets art.
Deep inside a Calatrava - preamble
Most of us only experience haute horlogerie through a sapphire case back and while we are promised amazing finishing throughout the whole watch we for obvious reasons cant verify this for ourselves. Having acquired a ref 96 from 1943 with an unknown serv...
Part one - external appraisal
Normal 0 false false false EN-US JA X-NONE It doesn’t get much more exciting for me than this – a Patek Philippe on the bench! John from Malta sent this watch in for a service, and I’m more than happy to oblige. In my book, watches don’t get better than t...
Part two - cracking the back
My master watchmaker, George, agreed to take apart the movement with me. This not only offers me some moral support, but for the forensic work we want to do, it’s so much better to have another person to discuss findings with. To prevent further damage to...
Part three - the teardown
I just love how the bridges and cocks form a wave throughout the movement. It also separates the functions out nicely, and makes it easy to see how the movement works. Just stunningly beautiful. From here on, I use a movement holder to properly secure it....
Part four - the wheel train
Now on to the wheel train. The 12"'120 movement is beautiful in that it allows you to see the full transmission of power from the barrel (first wheel) through the centre wheel, third wheel, fourth wheel then to the escape wheel and balance. Notice the lit...
Now some questions...
First - do you think the dial is original? I'm not one of those collectors that likes to see battle scars so unless the dial is the one it originally shipped with I'll have it refinished. This is a watch that gets worn daily, not a museum piece. With that...
Great post. Thanks John
My opinion FWIW 1. Dial looks original and I would not refinish it 2. I would get the dent on the case fixed All in all a great watch Thanks Julian
I gets my vote for post of the year
I have no idea what I could add to such a nice post so I better shut up But I really, really, REALLY enjoyed this post. Thanks
Dear John: thank you so much for sharing...
... this beautiful post and exchange of information between you and your knowledgeable watchmaker. Not being myself a PP collector (though definitively I´m an admirer of the brand) and not having much technical knowledge about movements, I enjoyed so much...
I would...
Hi John, I am pretty sure the dial is in original condition - I would not restore it. The damage on the case should be an easy fix - go for it. The Calatrava is an all time classic design, Ref. 96 is a bit small - I have the larger Ref 570 which is the pe...
I've decided to..
Thanks Erich, The screws are fairly badly scratched so I'm having these poished along with a light polish of the regulator. The dent is going to be fixed and the hands lightly polished to remove the marks acquired over at least 6 previous services. I'm ex...
Great post ! Thanks !
Really a cool post, very interesting and very good pictures. I am looking very much forward to see the "reverse" process or at least the the finished piece. Best regards Georg