Haydn sent in this Patek Philippe for a service. The power reserve is very low, and it doesn’t run reliably, and I can’t pick up a signal on the timegrapher.
The calibre 350i is a pretty special construction, and the winding/stetting wheel on the back of the watch gives us a hint to that.
The dial has screws as dial feet, which are held with nuts in the movement – very nifty.
Just what you expect from a PP – very nice finishes throughout.
The winding stem is at 4 o’clock of the large blued screw, and left of it the Geneva Seal. Note that the barrel arbor isn’t jewelled. Now you can see why the winding/stetting wheel is at the back. The rotor doesn’t move on top of the movement, but around it, so a traditional winding stem couldn’t be fitted. This construction makes the movement nice and thin, even though it’s automatic.
The auto winder gears. the brass coloured wheel at the bottom is the one that engages with the rotor. The rotor only winds in one direction, as you can see from the ratchet wheel and its click. Apparently, the original calibre 350 had bi-directional winding, which caused a fair amount of problems, so the 350i (improved) has only uni-directional winding.
Here you can see the winding construction – the winding stem is held by a clamp with a blued screw. On the right side of the click wheel, the automatic winding mechanism sits.
Now the gear train is visible.
Now it’s time for the bottom plate.
The rotor, which is suspended from the inner rotor ring with ball bearing, which isn’t oiled.
All parts cleaned and ready for re-assembly.
Mainsprings aren’t available, but the old one is still in very good condition.
The escape wheel has cap jewels that can’t be removed, so they have to be oiled through the jewel hole.
The gear train is back in place.
The wheel bridge is mounted, and I can put the winding mechanism into place.
Now the auto winder gears go in.
And we have a beating movement.
Now I put together the bottom plate.
And the movement is ready for casing.
Back into service.And looking very good on the timegrapher, too!