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Other than Cousins, anywhere to buy GR mainsprings?


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Hello -  I'm trying to source a mainspring for the Seiko 70XX series (GR2377x) and Cousins is out of stock. Not the first time that Cousins seems to be the one and only place to get a mainspring (among other parts). Anyone aware of another way to order GR mainsprings and/or source a suitable replacement? I am resourceful and am aware of them popping up on ebay from time to time and the ability to get one from a donor movement. However, Seiko mainsprings often need a refresh more than their swiss brethren, IMO.

Thanks in advance!

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2 hours ago, MikeRaleighNC said:

I don't see them sold on their site. Should I just call them? I appreciate your help, thanks. (ps, love your youtube content)

Hey, big thanks. Cutting a balance staff on Friday and putting it on YouTube. The closeups should be great with my new setup.

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17 hours ago, MikeRaleighNC said:

Connected with Jules Borel; they show the 0201075 (barrel complex for the 7S26B/C as being a substitute for the 0201024 (70XX barrel complete). Though I read somewhere they have different specs; anyone know?

Ordered the 0201075 as a substitute for the specified 0201024; will report back whether it works (cannot find this question resolved elsewhere on the web)

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On 1/6/2021 at 10:17 AM, MikeRaleighNC said:

Ordered the 0201075 as a substitute for the specified 0201024; will report back whether it works (cannot find this question resolved elsewhere on the web)

Confirmed: 0201075 is a suitable replacement for the 0201024. The teeth of the 075 seem a bit rounder than the 024 (which each come to a point), but it seems to mesh just fine with the train. Power wise, it seems to have the same strength (0.11mm) as the 024, though I did not open the barrel to measure.

I have issues with 70XX movements having lower-than-ideal amplitude (180 to 210 degrees); I might try the 0.12mm strength mainspring used in 7s26c to see if it helps.

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 One of the problems with getting mainsprings now is there's a limited number of sources that actually make mainsprings. I've noticed sometimes with American pocket watch mainsprings Coming in a envelope with a company name. But when I look at the actual mainspring package I recognize the number is a GR number. So it's conceivable that generic mainsprings if their new could be what you're searching for perhaps.

16 hours ago, MikeRaleighNC said:

I have issues with 70XX movements having lower-than-ideal amplitude (180 to 210 degrees); I might try the 0.12mm strength mainspring used in 7s26c to see if it helps.

Seiko with their all their watches almost never gives you specifications except. The only place any references to amplitude is ever been found at least in the older tech sheets is the Seiko 4006. you will note that Seiko is not expecting huge amplitudes out of their watches they were designed that way.

Then I have a link below to a site listing lift angles. Looks like for the Seiko watches in the 7000 series it's 53°.

https://watchguy.co.uk/cgi-bin/lift_angles

Seiko 4006a amplitude 180° fully wound up.JPG

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On 1/6/2021 at 4:17 PM, MikeRaleighNC said:

Ordered the 0201075 as a substitute for the specified 0201024; will report back whether it works (cannot find this question resolved elsewhere on the web)

Strange that you dind't find the previous discussions on this subject, or to the 7S26 parts reference sheet that I maintain, it has that compatibility information and more.

https://docs.google.com/spreadsheets/d/e/2PACX-1vRN2UULQKTfKmhRStZhDdIOIQrqd6sPB-g6x2SKyQQjOvTBjG_7TQXQhAT4f1WqAX5QAPkIimi-3jqd/pubhtml

 

7 hours ago, Rafael said:

Seiko watches usually have a higher lift angle than swiss watches.  Make sure to check the correct lift angle prior to checking the amplitude.

Maybe you are referring to older or more exotic mov.ts? Because Seikos has 53 deg, pretty much the same as any ETA, for example.
Also, as often mentioned, having a "wrong" lift angle in the machine only influences the amplitude reading very little, as in 2 degs per one of difference. If one has low amplitude as the OP mentioned, can't blame that.

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6 hours ago, JohnR725 said:

 One of the problems with getting mainsprings now is there's a limited number of sources that actually make mainsprings. I've noticed sometimes with American pocket watch mainsprings Coming in a envelope with a company name. But when I look at the actual mainspring package I recognize the number is a GR number. So it's conceivable that generic mainsprings if their new could be what you're searching for perhaps.

Seiko with their all their watches almost never gives you specifications except. The only place any references to amplitude is ever been found at least in the older tech sheets is the Seiko 4006. you will note that Seiko is not expecting huge amplitudes out of their watches they were designed that way.

Then I have a link below to a site listing lift angles. Looks like for the Seiko watches in the 7000 series it's 53°.

https://watchguy.co.uk/cgi-bin/lift_angles

Seiko 4006a amplitude 180° fully wound up.JPG

Very helpful validation that a healthy vintage Seiko still might not achieve 250+ amplitude. Regarding lift angle, I have taken that into account (e.g. 53).

5 hours ago, jdm said:

Strange that you dind't find a pointer to the previous discussion on this subject, or to the 7S26 parts reference sheet that I maintain, it has that compatibility information and more.

https://docs.google.com/spreadsheets/d/e/2PACX-1vRN2UULQKTfKmhRStZhDdIOIQrqd6sPB-g6x2SKyQQjOvTBjG_7TQXQhAT4f1WqAX5QAPkIimi-3jqd/pubhtml

 

Maybe you are referring to older or more exotic mov.ts? Because Seikos has 53 deg, pretty much the same as any ETA.
Also, as often mentioned, having a "wrong" lift angle in the machine influences the amplitude reading very little, as in 2 degs per one of difference. If one has low amplitude as the OP mentioned, can't blame that.

Thanks for pointing this out; I did not uncover that in my search for the answer. Regarding lift angles, I can confirm some of them are higher. Notably, the 61XX and 63XX series are 54.5 and the 52XX series at 56. 

Thanks all for the helpful discussion. Hopefully folks find this feed useful in the future.

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9 hours ago, jdm said:

Strange that you dind't find the previous discussions on this subject, or to the 7S26 parts reference sheet that I maintain, it has that compatibility information and more.

https://docs.google.com/spreadsheets/d/e/2PACX-1vRN2UULQKTfKmhRStZhDdIOIQrqd6sPB-g6x2SKyQQjOvTBjG_7TQXQhAT4f1WqAX5QAPkIimi-3jqd/pubhtml

 

Maybe you are referring to older or more exotic mov.ts? Because Seikos has 53 deg, pretty much the same as any ETA, for example.
Also, as often mentioned, having a "wrong" lift angle in the machine only influences the amplitude reading very little, as in 2 degs per one of difference. If one has low amplitude as the OP mentioned, can't blame that.

You are correct of course, missed the fact it's not a vintage Seiko 😅 The last one I worked on was a 1970's Seiko (and quite exotic - 5126A) which had a lift angle (as far as I could tell) of 56 and from what I read that's not rare (although, as mentioned, they usually have poor amplitude to begin with. Ended on 240 if I recall correctly). Changed the amplitude reading quite dramatically. 

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