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Hello,
I've bought a soviet watch equipped with a Raketa 2609-1 movement. After disassembling/ reassembling, it is quite correct, except the beat error, which is quite high (> 5ms). Usually, I can correct it with the adjustable stud, but there is no such thing on this caliber, only a regulator. Is there a way (not too complicated) to reduce the beat error?

Thanks in advance!
https://1drv.ms/i/s!AmSEWqSryKqAmwlxJjjqf-HKI6eI?e=2YBcxm]https://1drv.ms/i/s!AmSEWqSryKqAmwlxJjjqf-HKI6eI?e=2YBcxm

Edited by BlueHarp
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3 minutes ago, BlueHarp said:

Hello,
I've bought a soviet watch equipped with a Raketa 2609-1 movement. After disassembling/ reassembling, it is quite correct, except the beat error, which is quite high (> 5ms). Usually, I can correct it with the adjustable stud, but there is no such thing on this caliber, only a regulator. Is there a way (not too complicated) to reduce the beat error?

Thanks in advance!
https://1drv.ms/i/s!AmSEWqSryKqAmwlxJjjqf-HKI6eI?e=2YBcxm]https://1drv.ms/i/s!AmSEWqSryKqAmwlxJjjqf-HKI6eI?e=2YBcxm

Only by adjustment of the collet that holds the hairspring. Its an interesting exercise for a beginner in how to trash the hairspring.  Any way you can practice on something that doesn't matter first.

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Here's a post that explains how to spin the collet to reduce beat error.

These lessons were designed for those that were complete beginners, so I had them remove the balance and hairspring from the cock to do this task, but if one feels confident, the collet can be turned whilst in situ. You just need a balance tack the has a table for the balance to sit on and with an oiler going between the hairspring coils the collet is turned that way. If really confident, just a normal balance tack can be used.

 

Also I roughly worked out how much to turn the collet depending on how much beat error there is.

If a watch movement has a 300 degrees amplitude and it is an 18000 bph movement, that equates to the balance moving 1500 degrees in total in 1 second, which is 1.5 degrees of movement for every millisecond. An 18000 bph watch ticks five times per second, which is 5 times 300 = 1500 degrees. So, if your movement has a beat error of 5 milliseconds the collet needs to turn approximately 7.5 degrees. This is a rough estimate.

Edited by Jon
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I never fancied doing it from a tack, I used to do it with the cock stuck down on its back or its side and pull the balance wheel out to reach in to the collet. Until i tried it , i prefer doing it whilst hanging from a tact now. I made myself a big seven foot one from a sunshade base and 2 inch steel tubing, i have to be quick though, my arm gets tired and i fall off 🤪

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Thank you for your help! I tried to turn the collet and I was successful to some extent. The beat error is now 3.7ms instead of 5.5. I'm afraid to go further on, as this kind of work is very delicate.

I wonder what effect such a beat error can have on the caliber? Is it risky to leave things as they are?

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16 minutes ago, BlueHarp said:

Thank you for your help! I tried to turn the collet and I was successful to some extent. The beat error is now 3.7ms instead of 5.5. I'm afraid to go further on, as this kind of work is very delicate.

I wonder what effect such a beat error can have on the caliber? Is it risky to leave things as they are?

It is a tricky operation for a beginner but if you intend to work on older vintage watches especially the cheaper ones you will come across from time to time. Same goes for non shock protection, its something you will have to get used to. Just practice doing it with a scrap watch.

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13 hours ago, BlueHarp said:

I wonder what effect such a beat error can have on the caliber? Is it risky to leave things as they are?

The only risk is when the watch has stopped due pover reserve end, to need shaking to start when wound.

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Ah ok. Very interesting. The beat error is now 2,3 and the watch starts by itself when wound. That could be better, but I'm satisfied with that result.

Thanks for your invaluable help. This forum is fantastic for those who learn watch servicing as a hobby 👋

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