seiko 11a mainspring?

[Ishima]

Quick one, I'll probably just have to find a mainspring the hard way, by measuring, but I thought i'd check to see if if anyone knew what mainspring a seiko 11a needs.
http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&&2uswk&Seiko_11A
 

[rogart63]

https://www.ebay.co.uk/itm/Seiko-401-110-Mainspring-Ressort-Muelle-Zugfeder-Molla-1104A/162358367342?hash=item25cd50146e:g:kmAAAOSwZQRYepH-

[Ishima]

Thank you for your speedy reply rogart. I don't suppose you know the difference between th 1104a mainspring and the 11a's mainspring? (im assuming there is one, however small, as they are under different Seiko part numbers) the other thing is, I should like to get this from a supplier if possible, for business purposes.

[rogart63]

12 hours ago, Ishima said:

Thank you for your speedy reply rogart. I don't suppose you know the difference between th 1104a mainspring and the 11a's mainspring? (im assuming there is one, however small, as they are under different Seiko part numbers) the other thing is, I should like to get this from a supplier if possible, for business purposes.

Just googled my way and then found boley had a number for the mainspring. 401 113. Then is googled that and found this on  ebay. Didn't do much research. Have checked if cousinsuk has any parts? 

If i look on boley.de they say ersatz 03567 for 1104 

http://boley.de/en/caliber/watch-movements/hattory-seiko/6924

and if i look at 11A they saye ersatsz 03567 also 

http://www.boley.de/en/caliber/watch-movements/hattory-seiko/6895?q=

Then look at cousisnuk for 1104A they have a replacement  mainspring GR5458. So that must work in the 11A also. 

Edited January 21, 2018 by rogart63

[Knebo]

Hello @Ishima, hello all,

Did you find a suitable mainspring?

I'm also servicing a Seiko 11A right now and I am unsure.

I measured the mainspring I found in the barrel as 1.6 height and 0.06 thickness; with a barrel diameter of 5.2 (maybe up to 5.5). Despite @rogart63's unquestionable logic about the supposed compatibility of the cal 1104 mainspring, the GR5458 is 1.85 high and the barrel is 6mm. That seems very large for the barrel I'm working on.... I have my doubts.

Any feedback?

Cheers!

 

 

EDIT: I found this. As you can see indicated by red, the mainspring for cal 1104A is NOT compatible with cal 11A. The parts printed in light letters are compatible, but those in bold are not.

But the question remains, what are the "official" measurements of the 401.113 mainspring...?

 

EDIT No2:

Based on my own measurement, I think this one is the closest match:

 

But still looking for clarity...

Edited July 20, 2023 by Knebo

[JohnR725]

2 hours ago, Knebo said:

But the question remains, what are the "official" measurements of the 401.113 mainspring...?

Seiko is not going to give you an official measurement as you're supposed to purchase the mainspring by part number. then the link below has parts including two separate mainsprings of different widths. Giving you even more choices.

then of course there's the mainspring catalog

http://cgi.julesborel.com/cgi-bin/matcgi2?ref=SEK_11A

 

[DrHWO]

3 hours ago, Knebo said:

what are the "official" measurements of the 401.113 mainspring...?

You may have already looked here, but on the occasions I've used this, it's been right. https://watchguy.co.uk/cgi-bin/mainsprings

 

[Knebo]

Thanks so much for the replies!

But has become even more mysterious... 

@JohnR725: Jules Borel suggests such drastically different mainsprings?? How? 0.7 and 1.1 thickness... and more crazy even, barrel diameters of 6.5 and 10?? Impossible that this makes any sense. The watchguy.co.uk link from @DrHWO also suggest the latter (1.1. thickness and 10mm barrel diameter). But it cannot be correct. 

The fact: the barrel has a diameter of 6mm. I'd even have doubts that 6.5 would fit.. but 10mm: a joke.

So, I guess if I dismiss the outrageous one (on Watchguy and in @JohnR725 second screenshot), there are MS-714E and GR4428. At least they agree on 1.60 height, 0.07 thickness and lenght of 240/242. I guess I'll just try my luck even if I'm worried that the barrel diameter of 6.5 is just a bit too large (again, I measure 6).

But happy to read more of your thoughts

 

Screenshot also from Jules Borel (note that the MS-714E is listed as the replacement for 1.50 x 110(=0.11mm?) x 420, hahaha, how??)

[DrHWO]

11 hours ago, Knebo said:

.........I guess if I dismiss the outrageous one............

My bad! 401-113 isn't listed on watch guys mainspring page. Clearly I need to leave this to the professionals!

[JohnR725]

I thought we would have fun and see how much more confusion we can have today. So for this I'm going to bestfit online and we get this. So we get the generic first and then we get the original. The only minor annoyance of the online edition is is no pictures and we don't get a better description of the mainspring but we will get a cross reference

first the cross reference of the original number of very few watches using that spring.

then the cross reference of the substitute number or the best fit number if you want

then what's interesting about the alternative numbers or the MS number is it's basically the Denison size of the mainspring with a letter for the length is brings up an amusing problem but it's not much of a problem bestfit has a different letter than we have up above but there's three springs are probably all work just fine

and just in case you don't have a listing of those numbers I've attached something with the listing and a bunch of other bonus mainsprings listed also.

Oh and if you want to worry about thing as their other dimensions that are not listed that are really important. Like the center curvature that fits over the arbor if it's the wrong size it's an issue and other mainspring this big it's going to be a major issue to do anything about it you can sometimes squeeze it for mainspring on a pocket watch if you're lucky you might not break it but on a tiny watch it better be right the first time I would look on eBay and see if you can find an original spring.

 

Mainsprings Cas-Kar Catalog 2018.pdf

[Knebo]

1 hour ago, DrHWO said:

My bad! 401-113 isn't listed on watch guys mainspring page. Clearly I need to leave this to the professionals!

I don't think there was anything wrong with your answer! I used WatchGuy before and I hasn't failed me until this time. Thank you anyway!!

 

11 minutes ago, JohnR725 said:

I thought we would have fun and see how much more confusion we can have today

 go for it! 

As much confusion as you may try to create ;-), your sources and attachments are always of great value! I always learn.

In this case, however, your post is rather reaffirming, not confusing. It confirms that I should go for either of the following. If the 6.5 diameter of the GR4428 fits, perfect. If it's too large, the GR4427 will be the next best thing. With regard to the center curvature, I'll have to cross my fingers.

Thanks again!

[Knebo]

On 7/21/2023 at 11:37 AM, Knebo said:

If the 6.5 diameter of the GR4428 fits, perfect. If it's too large, the GR4427 will be the next best thing.

So I can report that GR4428 does NOT fit from the washer. Too large for the barrel. 

I'll be ordering GR4427. 

[Knebo]

Well well well, I got GR4427 now, and it's also not working properly.

It does fit in the barrel just fine, BUT the inner curvature doesn't work (just as @JohnR725 warned). Specifically, the size of the last/center coil is too large for the unusually small barrel arbor of the Seiko. It won't hook properly.

I've now found and ordered an NOS Seiko spring #401.113 on eBay. 

Again, I'll report back.

[Razz]

On 9/6/2023 at 3:35 AM, Knebo said:

Well well well, I got GR4427 now, and it's also not working properly.

It does fit in the barrel just fine, BUT the inner curvature doesn't work (just as @JohnR725 warned). Specifically, the size of the last/center coil is too large for the unusually small barrel arbor of the Seiko. It won't hook properly.

I've now found and ordered an NOS Seiko spring #401.113 on eBay. 

Again, I'll report back.

On some mainspring you have to heat the inner coil and use rounded pliers and tweezers to shape the coils smaller to fit the arbor. A denatured alcohol lamp or solering iron will work.

Look up Alex Hamilton the US watchmaker who has has a tutorial video on his Youtube channel. Do not try to bend without heating first as it will break. I am getting prepared to try one myself.

[Knebo]

10 hours ago, Razz said:

On some mainspring you have to heat the inner coil and use rounded pliers and tweezers to shape the coils smaller to fit the arbor. A denatured alcohol lamp or solering iron will work.

Look up Alex Hamilton the US watchmaker who has has a tutorial video on his Youtube channel. Do not try to bend without heating first as it will break. I am getting prepared to try one myself.

Hey @Razz, yes, good point, I'm sure that's possible. I did something similar with a Vostok mainspring (the bridle had broken off and I just "bent" back the last bit of the mainspring to create a new bridle. It worked. Back then, I just used a normal lighter... that was sufficient and the watch is still running very well.)

In this particular case, I have already ordered an original Seiko spring and I hope that it'll just fit.

[Knebo]

Well, getting the original Seiko mainspring made things easy. It just fits with the right inner coil for the arbor. Seiko part 401.113. 

I have to boast a bit on this occasion... I achieved oiling perfection on the pallet stone lubrication. Note that this movement is 13x15mm small and that the parts are absolutely tiny. 

I oiled it last night by pure feel (I don't have a microscope). Checked today and I'd say that the oil contact area is spot on. No? 

The timegrapher trace is also spotless.

Before:

After:

 

Edited September 16, 2023 by Knebo

[DrHWO]

1 hour ago, Knebo said:

I oiled it last night by pure feel

Thats damned impressive. I'm still struggling with more "normal" sized pallet stones!

[JohnR725]

1 hour ago, Knebo said:

ell, getting the original Seiko mainspring made things easy. It just fits with the right inner coil for the arbor. Seiko part 401.113. 

Is it nice when you can just show something in and not deal with the nightmare of this is a small watching getting the mainspring in is a definite issue if it's not in the ring.

 

1 hour ago, Knebo said:

I oiled it last night by pure feel (I don't have a microscope). Checked today and I'd say that the oil contact area is spot on. No?

Like everything else in watch repair there can be some variations. But based on the amplitude it looks like you did good and the trace looks nice and clean if for instance you only have lubrication on one side that shows up on the timing machine.Oh and regarding the timing machine it is always best to check in more than one position like dial up and down and then one of the crown positions just because but yours is looking really good

4 minutes ago, DrHWO said:

I'm still struggling with more "normal" sized pallet stones!

Oh you can always go to pocket watches where I don't get concerned about the quantity of lubrication on the pallet stones at all. Pocket watches tend to be big enough that the rules of super minimalistic or else no longer apply. Or basically for the most part I just don't worry about it other than if I get too much where is not supposed to be I take the pallet fork out the rinse it off and put it back in again and see how things look.

[DrHWO]

You're right. It seems the pocket watch is less critical.  I've just completed a Waltham 610 grade (1920, so > 100 years old) and the pallet stones were bigger than the wristwatches I'm used to. I'm not sure how long it had been seized for, but it took several cleaning steps before the accretions of brass shavings and monkey brain oil parted company with the pivot holes (7 jewels).

Edited September 17, 2023 by DrHWO
spelling error

[JohnR725]

29 minutes ago, DrHWO said:

I'm not sure how long it had been seized for, but it took several cleaning steps before the accretions of brass shavings and monkey brain oil parted company with the pivot holes (7 jewels).

This is actually the best pocket watch to service what you're describing. Organic oils have an outstanding property of going bad with time. The outstanding feature is the watch stops and does not disintegrate over time. As modern lubricants don't disintegrate but at some point in time may not lubricate then things will start to wear out especially a seven jewel watch. So basically it means a cleaning ok a really really good cleaning and maybe a little more cleaning and a new mainspring and you have a beautiful functional watch.

Although brass shavings in a watch or never desirable. I find a lot of times the keyless and other places where you have a steel wheel rubbing on a brass surface is where you will see the most wearing. So for things like that I just take the steel wheel and use of Pisa lapping film across its flat surface and knock off any edges that have developed over time and that seems to help at least hopefully. But yes a lot of the early keyless works there's a lot of metal on metal.