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.
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.
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.
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!
Have seen quite a few of the 497 movements and most have a broken banking stop spring or the fourth wheel pin is broken so that the seconds hand will not fit. A few have had escape wheel failures and all of the parts for these are expensive.
Yes, it’s not a watch that you can afford to wear regularly. Best kept in a collection and taken out once a year for Christmas 😉
Christian is getting really good at these FutureMatic watches!:) Fun to watch when he gets them working again!
Can anyone tell me the Best Fit # for the hacking lever ?
My movement seems loose in the case, my watch maker thinks there is a ring that goes around the movement ? Please someone help me on this ? Again Best Fit # would help.
There is no Best Fit number for the hacking lever – its unique to this Jaeger Le Coultre movement (817/497) and is NLA.
You may find one secondhand, but it will be very expensive.
On the plus side, the watch will work fine without it and many that I’ve seen for sale have already lost theirs.
I have a couple of repaired levers (same process that you can see in this post), but I only use those for clients that send in their watches for repair and service, I’m afraid.
Dear Christian,
I have never posted any comment although I read all your posts since quite some time ago. I can only congratulate you for the craftsmanship work you do on resurrecting this old pieces by being able to manually make parts. I can tell you than very few watchmakers are willing to take the time and skill to do the work you do- if they don’t have the parts they just say it is impossible to solve.
Cheers from Barcelona
What an… interesting design! Marvellous though 😉
Could the mainspring be replaced with a standard slipping auto spring of similar dimensions and so make the hook mechanism redundant?
I’m afraid not – the power reserve indication wouldn’t work if the mainspring slipped.
Christian, words can’t express my gratitude. Thank you for being able to fix this watch and I thoroughly enjoyed following the progress of this project. You are a true professional and I look forward to receiving the watch back in Shanghai.
Out of curiosity Christian, what does it mean to you when you talk about “overwinding the mainspring”? I read constantly where watch “experts” insist that there is no such thing as an ‘overwound watch’, so to hear you use the term, I’m curious to hear a verdict from the master! 🙂
A bit of a special case here… If the oscillating weight wasn’t hooked, it would continue to try to wind the mainspring with considerable force – more than you can muster with a crown by hand, and that would break the mainspring.
It is true that it’s almost impossible to overwind a watch, unless you use brute force.
I love when you do this type of watch. I think the designer and owner each have a smile or furrowed brow of equal measure and often at the same time. The furrowed brow would only be equalled by the servicer of the watch, in this case Christian.
I love Jaeger.
Thanks for putting this one on the blog.
Is this another of those jobs that you shouldn’t really be taking on Christian? 😉
Probably 😉
Definitely – but I’m glad you do!
Well this one blew my mind! A really fun timepiece and such ingenuity 😉