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7S26 balance spring, what's up with it


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Working on a 7S26 for a mate, I've got a new balance in the mail because I'm not super confident I can fix this, but I'd still like to try.

image.png.437bb105d85db4df9c2d4c4f09449e23.png

It looks like the spring is pretty mangled to the right of the regulator pin, so I'm wondering if it might have been originally clamped in the pin there, and it's just slipped back a bit? Should I attempt to insert it more into the regulator, or should I leave it where it is and try and reshape it?

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You definitely need to reshape the endcurve and put the hairspring in the slot of the regulator. The regulator stud can be rotated to align the slot with the hairspring.

Seiko uses a system similar to Etachron. To remove the hairspring stud, you can use a fine tip tweezer to carefully wedge the stud out of the clip.

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1 hour ago, lexacat said:

Working on a 7S26 for a mate, I've got a new balance in the mail because I'm not super confident I can fix this, but I'd still like to try.

image.png.437bb105d85db4df9c2d4c4f09449e23.png

It looks like the spring is pretty mangled to the right of the regulator pin, so I'm wondering if it might have been originally clamped in the pin there, and it's just slipped back a bit? Should I attempt to insert it more into the regulator, or should I leave it where it is and try and reshape it?

Hi lex, some centering of those coils needs to take place. First make sure that the hairspring is thoughly clean and nothing sticky remains, magnetism shouldn't be an issue as modern ( last 70 years bright nickle alloys ) hairsprings are non magnetic. Next check its freedom between the regulator pins, which at the moment doesn't look like it is, seems to be nipped, notice the gap between the end curve and the.1st coil is wider on both sides of the regulator. Once free turn the stud for some concentric adjument of the coils, if that looks ok then the regulator pins can be closed up and checked for hairspring freedom all along the terminal curve. Maybe some reshaping of it like Hector suggests as the curve looks a bit raggy.

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Yes, reshaping of the end curve is definitelly needed. This can be done without taking out hte stud from the holder at all.

The spring is not clamped in the stud, it is glued with heat melting glue and it is not protrding from the other side like in old watches that have 'reserve'. So it is as it should be there.

Edited by nevenbekriev
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@lexacat reshaping hairsprings is more of an art than a science, sometimes you take a spring and make a minor tweak and everything miraculously falls into place (those are the good days), other times you can be 99% done and make a final micro adjustment and it ends up worse than you started. But practice and experience will get you there in the end, you can go from this:

0121.thumb.JPG.7ed6461bf5a1eaf883a016603438a0e0.JPG0122.thumb.JPG.728184d5b3b2422a7049d441ecb9e9b5.JPG

 

To this:

0126.thumb.JPG.b66f5170961295eb56dacffe6151c5a6.JPG

Only general advice I can give is to look for the problem area (eg where the coils are touching) and then look 90 degrees away for the cause and make your adjustment, when making an adjustment hold the coil with a fine set of tweezers (No 5) and then stroke the spring on whichever side of the held section works with another set of closed No 5's or thin tool (eg oiler) to make the adjustment - repeat as necessary, if you try make an actual bend you will inevitably overdo it and start the downward spiral of fixing the fix, then having to fix that fix......take regular breaks to avoid frustration and re-fucus your concentration.

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On 1/29/2024 at 7:27 PM, lexacat said:

mangled

I think mangled is a bit of a harsh word here. let's interesting in the world of horology the battle of Japanese watch manufacturing with the Swiss is that sometimes they share things like the system here of the regulation on the stud commonly called a Etachron system the Swiss hold the patent for one part and the Japanese hold the patents for the other part.

I'm attaching an image so you have a better idea of how things look. For now what I would do is just open the regulator up to its maximum and just move it out of the way see you can see if they hairspring got bent there. you and up with way more adjustments which of course will cause way more confusion when you're trying to figure out what you're trying to do here. 

 

 

image.png.06c75573e1b15435a7d93f2c15dc35d7.png

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  • 4 weeks later...

Hey guys, thanks for all the great info! I've been snowed under with work but hoping to have a crack at this when I get a spare second. I've got a new balance to pop on this if I screw things up, but hopefully I can get it looking good again 😃

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