Bellmatic alarm spring replacement i think. What ye think???

[slipperywhen wet]

Measured the old broken spring although exact length is hard to establish and only used a vernier caliper (will mic it tomorrow) but found an equivalent mainspring that should do the job . What do the experts think?


This site [size=78%]http://www.ofrei.com/page1266.html[/size] and the spring closest is 512k .

[rileynp]

Unless a reputable source claims to have used that exact spring successfully as you desire to in a 4006, it is a gamble.  The ends of the spring can cause problems if they are not sized correctly to the application, i.e. your mainplate and more importantly your alarm mainspring arbor.  Shaping a tempered alloy spring if the inner coils is too big or too small is not the easiest thing to do, even with the correct tools.

[slipperywhen wet]

That is quite true but it must be worth a try seeing as the alarm springs are unavailable new. Perhaps in an old case/ movement. Would be nice to know if a new replacement spring was available.


S.

[haloeight]

Geday,

I have a spare spring and arbor which I can send to you. You'll need to get it installed by a watchmaker, as without the correct tools and experience it's basically impossible. I'll PM you the details when I get a chance.

[slipperywhen wet]

Got a spring from Peter . Didnt want to pull the complete watch apart to fit the complete plate it was installed in so i carefully pulled it out and re-fitted it after lubing it up. Its quite easy to do if you practice with the old one a few times. A movement holder helps a lot.


I will report on fitting the spurious replacement off ebay if it ever arrives.