Mechanical WW Mainspring bridle position in barrel

Paul Raposo

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Nov 4, 2005
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I bought a new mainspring for a handwind movement and popped it into the barrel from the retaining ring and all went well until I realized I misjudged the position of the bridle and it's in front of the wedge inside the barrel as opposed to behind it or against it.

Does this mean I need to remove the spring and insert it again or can I put everything back together and when I wind the spring the bridle will slip around into place?

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Paul Raposo

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Nov 4, 2005
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I got everything back together and before recasing the movement I started winding it very slowly. On the fifth wind I could hear the spring slip and on the sixth wind the bridle locked into place inside the barrel. It took 29 turns to full wind.

Here's a pic of the spring that was in the barrel. The previous owner had the movement serviced two years ago for $327 CAD and service included a new mainspring per the receipt. This spring doesn't look very new to me.

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Al J

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Jul 21, 2009
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This is why I always use new alloy springs, because even if it was a "new" (never used) blued steel spring, it's very old already and they can still snap in short order.

These blued steel springs can still be bought from material suppliers, and I've ordered by caliber before and been sent blued steel springs. Now whenever I email a supplier asking for a spring by caliber, I always include "white alloy only" in my descriptions.

So it's very possible that the watchmaker did replace the spring, with a newly purchased blued steel spring.
 
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Paul Raposo

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Nov 4, 2005
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Cambridge, ON Canada
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So it's very possible that the watchmaker did replace the spring, with a newly purchased blued steel spring.
That's quite possible. I just assumed whoever did the work reused the original spring while charging for a new one.

The watch was taken to a local jewellery store for servicing but they send their watches out to someone for work. For years they were using the Sears store in Kitchener until they stopped doing onsite work. Not sure who they're using now.

I actually prefer blue steel springs for old pocket watches, set or not, especially 18 size movements. There has been a lot of debate here about new white alloy vs old stock blue steel in old PW movements, but I'm comfortable with the old blue steel.

The movement is running really well with very good amplitude, low beat error and running +3 seconds dial up. It appears a service was done, the mainspring notwithstanding.
 

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