This Longines that Stuart sent in has an unusual rotor for the auto winder – so I thought I’ll share a look at this movement with you.
And here is the calibre 340 in all its beauty. The rotor is mounted on a wheel that goes around 360 degrees, which in turn drives another wheel. That takes the gear ratio of the auto winding mechanism right down, and is an unusual design – probably not cheap!
The movement needs some attention, as the amplitude is pretty low.
The bottom plate is a nice sight indeed. The see saw construction of the intermediate winding/setting wheels reminds a bit of a pocket watch.
The unusual rotor with its bridge.
The wheel train. The solid wheel at the bottom is the one that the rotor wheel engages with to wind the movement.
The barrel is a sealed unit. I can’t find a new one, and the old one seems to be in good condition, so I will leave it in.
The centre wheel is set in its own cock.
The bottom plate wasn’t cheap to construct, either. Looks like money wasn’t too big a consideration when this movement was designed.
The cap jewels are translucent, and I’m not a big fan of that. They are easy enough to lose if they are ruby coloured …
For a movement without a date, there is no lack of parts!
As usual, I put together the base movement first.
I now have a decent amplitude. There is a bit of wear in the movement, and I blame the slightly jagged graph on the escape wheel / pallet fork. Still good for the age of the movement, though.
The bottom plate ready for dial and hands.
With a new crystal, the watch looks as good as new.