Is this the wrong spring??

[Lc130]

Hi All

I'm a beginner.  I got the spring shown below from Otto Frei in the US.  It's for an AS 1700.  The supplier looked up the part number from the movement number.  When I look it up at J  Borel I get the same part that Otto Frei sent.

The problem is that while the spring certainly appears fully into the barrel, the lid wont close.  I've tried several times.

Any thoughts?

Thank you

Charlie

 

[watchweasol]

Hi  Chek that the outer coil is below the rim where the barrel lid fits on if so it may be just a tight fit, some can be a bit of a pest and need some pressure but don't distort the barrel or the lid or you will get binding problems.  If the spring is higher than the rim its wrong. Use a micrometer and measure the old spring for height.

[oldhippy]

Here is everything you need about As 1700 its in PDF so you will need a program. I use Acrobat Reader

3903_AS 1700, 1701_Smaller.pdf

[watchweasol]

Hi Have a look at the attachment from Dr Ranff's site plenty of tech _ Watch Movements_ AS 1700.html_ Watch Movements_ AS 1700.html_ Watch Movements_ AS 1700.html

3903_AS 1700, 1701_Smaller (1).pdf

[Klassiker]

Hi Charlie,

as you suspected, it's the wrong spring. As suggested above, I checked the Ranfft site (a bit tricky to navigate from the homepage - click the "pink pages" button, then "archive", then in the category list "Archive: Watch Movements", then search for AS 1700. The mainspring is listed as Zf675, 1.20 x 9.5 x 0.10 x 315mm. You appear to have been sold a 3mm deep spring instead of 1.2mm.

[rogart63]

According to Cas-Kerr it should be the same as for the AS 1580 . And they have the same dimensions. https://www.jewelerssupplies.com/product10478.html

[Lc130]

7 hours ago, Klassiker said:

Hi Charlie,

as you suspected, it's the wrong spring. As suggested above, I checked the Ranfft site (a bit tricky to navigate from the homepage - click the "pink pages" button, then "archive", then in the category list "Archive: Watch Movements", then search for AS 1700. The mainspring is listed as Zf675, 1.20 x 9.5 x 0.10 x 315mm. You appear to have been sold a 3mm deep spring instead of 1.2mm.

Yup!  The new one measures 1.5 high.  The old 1.2.  Am I misreading the package label (beginner here)? It reads 3mm high, 0.105mm thick.  Is the last number the barrel diameter which I measure at 10mm.  

Interestingly, the same incorrect part comes up at J Borel.  How common is it that supply houses get it wrong?  As a follow up, where do they parts for no longer made watches?

It appears that the correct measurement is listed here https://watchguy.co.uk/cgi-bin/mainsprings

Thank you

Edited January 21, 2019 by Lc130

[Klassiker]

The spring in your photos measures 1.5mm high, not 3mm? I was reading the label on the packaging different to you. 3mm high, diameter 10.5mm and 13cm (or 130mm) long. Which thinking about it is far too low to be the length. And no information about the strip thickness is also unlikely. I am baffled, to be honest.

Oh, wait! I just put the code number into Google and ended up at the same place quoted by rogart63, on the Cas-Kerr website. The dimensions are not mm but inches! Still don't make complete sense to me, but the 13 is probably the length in inches.

As you can see from the discrepancy between watchguy uk (great blog and source of info for us beginners by the way) and Ranfft, the exact spring dimensions are not critical. Obviously it needs to fit in the barrel, and being too powerful (too thick, too wide) can also cause problems. There should be springs available on the market which will do the job, even if one of these two isn't available.

There is an Ebay seller in Mannheim currently selling an NOS barrel complete for EUR 16.90, but maybe not posting to the US.

[Lc130]

I believe the part label is measured in Dennison.  The conversion formula is here https://mb.nawcc.org/threads/metric-to-dennison-conversion-formulas.54587/

After reviewing several sites it appears

1.2mm = 3 dennison

0.105mm height = 10.5

300mm length = 13

http://www.gruenwristwatches.com/gruen-mainspring-sizes-in-dennison.php

http://watchinprogress.com/mainspring-size-dennison-to-metric-conversion/

https://www.jewelerssupplies.com/media/pdfs/MainspringsCatalog2018.pdf

 

[TexasDon]

4 hours ago, Lc130 said:

I believe the part label is measured in Dennison.  The conversion formula is here https://mb.nawcc.org/threads/metric-to-dennison-conversion-formulas.54587/

After reviewing several sites it appears

1.2mm = 3 dennison

0.105mm height = 10.5

300mm length = 13

http://www.gruenwristwatches.com/gruen-mainspring-sizes-in-dennison.php

http://watchinprogress.com/mainspring-size-dennison-to-metric-conversion/

https://www.jewelerssupplies.com/media/pdfs/MainspringsCatalog2018.pdf

 

Seriously? Dennison? That's even more arcane than the Lancaster measurement which American pocket watches use to denote size. It's based on 1/30 inch. Arrrggh! Just when I thought some of the fog might be dissipating. I wonder how Liberia and Myanmar, the only other two countries currently using the imperial system of measurement, contend with this?

Edited January 22, 2019 by TexasDon

[Klassiker]

That is just bonkers! No wonder they sent you the wrong size.

Well done for working it out. I checked Wikipedia, trying to understand the thinking behind this. Although it's not described directly, I guess it's something to do with the "American system of watch manufacturing".

[Lc130]

If you are really bored  http://www.nawcc-index.net/Articles/Watkins-MainspringGauges.pdf

From the intro I learned that in the 1800's he was trying to come up with a standardized measurement