MITKA

Service/Repair Longines Calibre 12.68z

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This lovely gold Longines is fully wound and not running, so I will give it some badly needed attention. It has one of my all time favourite movements, the 12.68z. 

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The movement looks good, but I suspect that the barrel bridge is worn causing the barrel to tilt and block the centre wheel.

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Someone scratched the barrel bridge around the click spring and the setting lever screw, but besides that the movement looks very good.

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As suspected the hole for the barrel arbor is worn.

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I start by broaching and then push fitting a new bush into the barrel bridge. Note the lovely machined click spring.

 

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I machine down the bush until it is flush with the barrel bridge.

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The old dirty mainspring.

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All the parts cleaned and ready to be put back together.

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I see that the balance moves freely after fitting the balance jewels. Those clear cap-jewels are always fun to look for when you drop them on our white floor…

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Clean mainspring fitted into the barrel.  I always find these T-end mainsprings a little tricky to fit, but practice makes master;)

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There is no free play in the barrel and the repair should last another 55 years of not longer:)

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Setting mechanism back in place. I really like how the spring is a part of the Yoke spring.

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The gear train moves freely now that the barrel is no longer blocking the centre wheel.

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The movement back in the case and ticking like it should.

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The 12.68 when in good condition never fails to perform. (It is noted that the lift angle is 44 degrees on this movement, so the amplitude is actually a little higher)

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It’s a great feeling bringing a non-runner back to life, especially when it looks this good;)

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It’s a sunny day so why not take it out!

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