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fhf 909 running slow


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FHF 909 in vintage Lucien Piccard is showing average  +10 sec per day, beat error 0.5 and 210 amplitude in six postions.   Seconds hand is circulating at correct speed.   The problem is the minute and hour hands are drastically slow and often stop.  This is all after I serviced.  Thought it might be binding but the movement never stops or slows.. just the two hands.   The watch sets and winds with ease.    Not sure what could be causing this.  I'm confused...

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  • 1 year later...

Are any of the hair spring coils sticking together or touching, or touching the underside of the balance bridge, or fouling the balance wheel arms?

If so then you either have a contaminated or magnetised hair spring (coils sticking together) or a distorted one.

Any of the above will cause the rate to be too fast.

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