Recording jumper for Heuer 12 is too strong

Chris Radek

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Apr 13, 2014
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Hi friends,

I'm servicing a Heuer 12 which had, among many other problems, a broken recording jumper. There are two, which in this model seem to be the same part, 8270, for the hour and minute recorders. The owner knew this and sent with the watch a new jumper, which came from a reputable parts dealer, and was very expensive (he sent the receipt too.) The new spring, which looks identical to other new springs I see on ebay, is way too strong. You can see the new one (top) in my photo compared to the remaining original (bottom). Not only is its resting position much farther inward, the spring itself appears thicker and feels stronger.

The watch stops when trying to move whichever register this new jumper is on, but the old one works fine in both places.

Please believe me that the watch is correctly serviced. It is running perfectly and all functions are adjusted correctly and work right. If I remove some of the tension by pressing the arm of the spring outward, the register advances properly.

Of course I tried some gentle pressure and that absolutely didn't bend it; it's much harder than a hairspring. My gut tells me it will certainly break before it will bend into a new shape.

The foot can't be pivoted because it's placed definitively with a pin and a screw.

I feel like the chances of being successful shellacing it to a fixture somehow and thinning the spring part on an arkansas stone would be low. Thinning it the easy way (flat) would be easier, but I could only remove at most maybe a quarter of the thickness, and I doubt that would fix it.

I have many hours and some serious parts expenditure in this repair and I'm irritated and blindsided by this last problem. What remedy haven't I thought of? I would certainly like to have a correct part, but it's not clear to me how to get one. There seem to be a lot of these "bad" parts out there.

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praezis

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Feb 11, 2008
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Did you measure the thickness difference of both parts?
If supposedly too hard, you may blue the spring part?

Frank
 

gmorse

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Jan 7, 2011
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Hi Chris,
My gut tells me it will certainly break before it will bend into a new shape.
If its temper is correct for a spring, (on the pale side of blue for something this weak), then you can safely bend it enough. Just try and alter the whole spring and not just bend it at a single point.

Regards,

Graham
 

Chris Radek

NAWCC Member
Apr 13, 2014
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Lincoln, NE, USA
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After my customer and I agreed it was no use as-is (and he couldn't return it), I went ahead and bent it, much farther than I thought was safe, and was successful.

Thanks for your encouragement!
 

gmorse

NAWCC Member
Jan 7, 2011
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Breamore, Hampshire, UK
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Hi Chris,

Glad it worked, steel is amazing stuff isn't it!

Regards,

Graham
 

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