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Need new Mainspring for Coventry Astral

SteveTimes

By SteveTimes
in Watch Repairs Help & Advice

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SteveTimes Member

SteveTimes

Posted
Posted

Hi guys,

I'm servicing my Coventry Astral and discovered the Mainspring has snapped at the end. It is a Swiss movement, here are the measurements:

Diameter:  17mm
0.25 mm thickness
2.1 mm height
500mm

I am also needing a 60 tooth ratchet wheel, it's missing a tooth. It's diameter is 14.5mm.

Can anyone help me out? I'm a newbie and don't know where to get these things yet 🙂 Thank you all

PXL_20211114_202525568.jpg

PXL_20211114_202542847.jpg

jdm Distinguished Member

jdm

Posted
Posted
9 minutes ago, SteveTimes said:

.It is a Swiss movement, here are the measurements:

Post a picture of the mov.t to identify it and search for its parts. You can get generic mainsprings and even search them by size on Cousins UK, but not for specific parts like a ratchet wheel.

 

9 minutes ago, SteveTimes said:

I'm a newbie and don't know where to get these things yet

Have a read of our pinned topic:

 

watchweasol Distinguished Member

watchweasol

Posted
Posted

Hi  The usual ports of call    are cousins uk, HS Walsh, AG Thomas, in the uk    Or Jules Borel, Esslinger, Timesavers, Otto Frei in the USA.   a trawl of the net will find others Im sure.      cheers

watchweasol Distinguished Member

watchweasol

Posted
Posted

Hi  The Astral brand is associated with Williamson / Smiths .  The Coventry Astral shown below i.  You may need to look for a donor  for spares watch on the Ebay. information in the pocketwatch database is nonexistant for smiths

dealer_vintagewristwatch_superhighres_1551368203949-8907756736.jpg

SteveTimes Member

SteveTimes

Posted
  • Author
Posted

Okay guys, I've emailed HS Walsh & AG Thomas to see if they can help. I also opened a request on Cousins UK but I don't think they like to operate that way (They make it very clear on their website that they don't assist with finding parts, you just have to know the exact item code for ordering) But we will see anyway.

KarlvonKoln Distinguished Member

KarlvonKoln

Posted
Posted
12 minutes ago, SteveTimes said:

Okay guys, I've emailed HS Walsh & AG Thomas to see if they can help. I also opened a request on Cousins UK but I don't think they like to operate that way (They make it very clear on their website that they don't assist with finding parts, you just have to know the exact item code for ordering) But we will see anyway.

I ask, only because I do not know your location: would you have any difficulties receiving a shipment from the USA?  If not - Ofrei Watch, one mentioned by Watchweasol, should be able to help.  They do not require a part number for a mainspring.  They *do* require: overall Length, Width, and Strength (thickness) as well as what kind of anchor points the spring will use.  You look up your parameters on their site and order a spring.  I have had much luck with them.  It is more work to measure out everything on the spring barrel (as I sometimes do not use the old spring if it looks like a poor-fitting replacement) but when you are done you know that the spring you request will fit and will work. I have even been able to get a hard-to-find Swiss spring for a size 0s cylinder pendant watch.  I rely on Otto Frei quite a lot.
Let us know if this will work for you:

https://www.ofrei.com/page_110.html

KarlvonKoln Distinguished Member

KarlvonKoln

Posted
Posted
27 minutes ago, SteveTimes said:

Hi @KarlvonKoln, Am I missing a measurement that I haven't listed already? I thought I had everything measured. 

I believe you listed everything.  I was just reciting what they use.  The annoying thing about Otto Frei is that they sometimes still use inches for the length measurement (and in measurements for other parts) and there are actually a few of us Americans who use the metric system for most of what we do, and when we encounter inch requirements we have to convert, and it's a pain.  America still uses the Imperial system for far too much.  Try to get hold of a metric micrometer over here.  I finally got one, but it wasn't cheap. 
Anyway, I think Otto Frei will be able to help with the spring.  But for the ratchet wheel, I agree with the others saying that a donor movement may be your only hope there.

praezis Distinguished Member

praezis

Posted
Posted
16 hours ago, SteveTimes said:

Diameter:  17mm
0.25 mm thickness
2.1 mm height
500mm

Are you sure about the thickness size?
It looks much too thick, average size for a 17 mm barrel is 0.20 mm (and length 500...550 mm).

Frank

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