Ethan from Shanghai sent in this LeCoultre Futurematic. If you are a regular reader, you have seen one of these before on this blog.
The LeCoultre calibre 817 is one of the weirdest movements around. The auto winder and power reserve construction are over-engineered and also not very durable. LeCoultre used a non-automatic hooked mainspring, so in order not to break the mainspring, the winding weight is held to the side with a hook to prevent overwinding. Once the watch winds down a bit, the hook releases the winding weight again…
You can’t manually wind the watch. On the case back, you have a wheel to set the watch. In this photo, it’s in resting position. To wind the watch, you press the wheel towards the inside of the case, which operates the hacking second lever, and also engages the wheel with the setting mechanism, so the watch can be set by turning the wheel. When that’s done, you pop the wheel back to the outer position, and the watch starts up again as the hacking lever is moved away from the balance.
With the movement taken out of the case back, you can see that the hacking second lever is badly damaged – somebody took off a bit of it, and also damaged the plate in the process.
The bottom plate with the auto winding mechanism. The hook that holds back the winding weight is completely missing, so the watch will overwind the mainspring.
The banking stop spring is broken, so I’ll need a new one as well.
The screw with the arrow pointing to it is to let down the power. There is a hole in the plate through which you can reach the click spring on the bottom plate whilst holding this screw with a screwdriver. You can then slowly release the mainspring.
The gear train.
This must be the most complicated centre wheel ever.
The mainspring tension has to be released whilst holding the barrel arbor in a pin vise, and holding the barrel whilst removing the two little screws.
The barrel and arbor assembly. The plate with the four holes rides up and down depending on the state of winding.
The cone visible at 3 o’clock is pushed to the side by the plate on the barrel, this changing the power reserve indication.
The parts go through the cleaning machine.The mainspring has to be pre-tensioned by 1 1/2 turns before putting the plate and screws in. This again is done with a pin vise.
Now I put in the balance jewels.
Now I can start on the wheel train.
Ready for the bridge.
The wheel bridge and the auto winder bridge in place.
The click wheel and click are on the bottom plate, which is quite unusual.
And so are the wig-wag wheels.
Here, you can see the auto winder assembly on the bottom plate. On the left side of the click spring, you can see the little hole that is used to release the tension from the mainspring before taking the movement apart.
The lever on the right is pushed to the side as the mainspring is wound.
The red and white indicator for the power reserve in place.
And the little second disc with the arrow goes on. You can also see the new hook, which I got from Zaf Basha, at 9 o’clock, very close to the pin that engages the hook to stop the weight.
I put the oscillating weight in, and notice that it’s missing its bushing.
Performance is very good.
So off to the lathe to make a new bush for the oscillating weight.
The outside diameter is correct, and I’ve drilled a hole that I can later widen with a broach.
The raw bush. I smooth the sides, and rivet it into the oscillating weight.
Now, with a broach, I can widen the inside diameter until it fits.
The diameter is now correct, and I clean the weight and put it into place.
A perfect fit. The oscillating weight moves easily without side shake.
And now I can case the movement.
I clean and grease the setting mechanism.
Last, but not least, I have to deal with the broken hacking second lever. After a bit of head scratching, I decide to find some material that I can solder on.
And here it is – a washer that is also 1/10mm thick – the same as the lever. I solder it on.
Here you can see the lever back to its correct shape.
And it’s back in place and working.
The movement is in the case back, and I check that the setting and the hacking second feature work properly.Cased with a new crystal, and back to working order!