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Re-sizing a mainspring

Neverenoughwatches
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Neverenoughwatches Distinguished Member

Neverenoughwatches

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Eyup watch peeps, i hope everone is well. I've just had a random idea maybe crazy ? ( hey I'm a bit fruit loop what can i say ). It dawned on me today while playing with a mainspring punch that a mainspring could theoretically be adjusted not only in length but also in height. If coiled and retained it could be ground or lapped to size ( yes I'm leaving out loads of details on the process so start thinking ). What are people thoughts ?  Barmy ? Or,  you may just have something there ? 

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nickelsilver Distinguished Member

nickelsilver

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Done it numerous times. There's a limit how much you can take off, and the sides become sharp rather than rounded and that has to be addressed. You can't take a 2.00mm spring down to 1mm for example, there won't be a hole anymore. I've only done it when there was simply no other option, typically ultra thin pieces. You really have to glue (I use black Loctite super glue) it to a flat support, and have a bit of a method to keep it uniform. If you don't glue it down, inevitably the center coil becomes thinner than the rest. Of course you have to grind a bit, then unglue and reglue the other side and do the same. It's a hassle, but can save the day.

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Neverenoughwatches Distinguished Member

Neverenoughwatches

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17 minutes ago, nickelsilver said:

Done it numerous times. There's a limit how much you can take off, and the sides become sharp rather than rounded and that has to be addressed. You can't take a 2.00mm spring down to 1mm for example, there won't be a hole anymore. I've only done it when there was simply no other option, typically ultra thin pieces. You really have to glue (I use black Loctite super glue) it to a flat support, and have a bit of a method to keep it uniform. If you don't glue it down, inevitably the center coil becomes thinner than the rest. Of course you have to grind a bit, then unglue and reglue the other side and do the same. It's a hassle, but can save the day.

Thanks Nicklesilver, i just wondered if it was possible 🙆, the details i can now play around with. The main issue i figured would be getting rid of the burr.

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oldhippy Distinguished Member

oldhippy

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Rather silly if you ask me. If you do not do it right then the spring will not be the same strength from end to end, it could even cut or mark the coils or the inside of the barrel and the underside of the barrel lid. Why not just buy a spring if you cannot get the correct height get the next to it. There are plenty of places on the internet to search. Even members on here help out with stock.  

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Neverenoughwatches Distinguished Member

Neverenoughwatches

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1 hour ago, oldhippy said:

Rather silly if you ask me. If you do not do it right then the spring will not be the same strength from end to end, it could even cut or mark the coils or the inside of the barrel and the underside of the barrel lid. Why not just buy a spring if you cannot get the correct height get the next to it. There are plenty of places on the internet to search. Even members on here help out with stock.  

Ahh more to think about, i didn't expect it to be easy. It was only an idea to see if it was possible, i also have thousands of springs .

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