Jump to content

Recommended Posts

Posted

I need to get a replacement balance for 7s26b.
I looked on eBay and there some NH36 balances, some state for B, some for C, some for all of them, others are very cheap from China and they don't even mention the NH36. It doesn't give me a great deal of confidence in getting the correct one. Are the NH36 interchangeable with Seiko?
How do I ensure I get the correct one?

Posted
8 hours ago, PeterS said:

I need to get a replacement balance for 7s26b.
I looked on eBay and there some NH36 balances, some state for B, some for C, some for all of them, others are very cheap from China and they don't even mention the NH36. It doesn't give me a great deal of confidence in getting the correct one. Are the NH36 interchangeable with Seiko?
How do I ensure I get the correct one?

As mentioned in many other similar threads, all Seiko balances interchanges between 7S26B/C, as well 4R36, 6R15, SII NH2x, and 3x and even the older 7S26A or 700x if you swap the balance cock. You can use my pars document to know more details
https://docs.google.com/spreadsheets/d/e/2PACX-1vRN2UULQKTfKmhRStZhDdIOIQrqd6sPB-g6x2SKyQQjOvTBjG_7TQXQhAT4f1WqAX5QAPkIimi-3jqd/pubhtml

People had mixed luck with the Chinese balances, which are of inferior quality. But since the original one is too expensive when for 5 pounds more you can get a brand new NH36 from AliX, that is preferred way to long lasting, sure repair that will also add manual winding and seconds hacking.

  • Like 1
Posted

Thank you very much for the information and the spreadsheet.

You are right, considering the price of the balance wheel and the complete NH36 movement, it makes sense to swap the movements.
As much as I would like to repair the Seiko movement it financially doesn't make much sense.
I bought the NH36 a while ago so I think now it's the time to use it and keep the 7s26 for spares.

  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • Very interesting! I answered the mail from Longines, explaining that I was a bit disappointed and that I wouldn't ask for a costly confirmation for a watch which isn't a high-end one ... and I received another email explaining that they couldn't not certify the authenticity of the watch, but they could specify that, according to the serial number on the caliber and to their handwritten records, the watch was produced in 1938. Great! @Mercurial I will take the measurements and will keep you informed. Thank you all. This forum is incredible 👍
    • Good stuff, thanks!!!  I'm going to save it and re-read your post and watch the video again.  I have a few follow-up question:  My understanding is that the spring vibrates or breathes between the the two regulator pins. When the pins are fully open the effective spring length is from the stud and theoretically no rate adjustment can be made by moving the regulator arm. As the pins are closed the spring gets closer to one side of the regulator block but doesn't touch a pin. You can still move the regulator carrier the entire terminal curve without upsetting the coils.  The rate can now be adjusted using the regulator because the effective spring length can be modified.  My question is: Does the hairspring bounce off and touch one of the pins as it breathes? Is that why the effective hairspring length is adjusted by moving the regulator?  And follow-up: How is amplitude affected by the spring between the pins? Does fully open pins, dial up position = max amplitude?  When spring adjusted to 1/2 width still = max amplitude? When I have crown down gravity is pulling the spring against one of the pins and I would expect rate to go up and amplitude to go down. Is that correct?
    • A quick Google for Longines 25.17 found several similar watches - like this one with writing on the case back similar to yours https://benjaminmarcello.nl/product/longines-cal-25-17-tank-from-1938/
    • Apps like Watch Accuracy Meter can be inaccurate, and will read some watches better than others.  What daily rate does Watch Accuracy Meter give you if you check the Longines once it’s been running for 24 hours? Best Regards, Mark
×
×
  • Create New...