Safe mainspring winder diameter for 14mm barrel?

[danderson]

I'm working on my first pocketwatch, which is a Molnija 3602 movement. I successfully took the movement apart all the way, except that I haven't yet opened the mainspring barrel and extracted the spring. Given the condition of the rest of the movement, I certainly need to do so to clean and re-lubricate, but my concern is that I'm not sure how to reassemble it when I'm done. Being from a defunct soviet factory, there doesn't seem to be any NOS for this spring, and while I could search for a close enough replacement, I would like to try and reuse the original parts if they're in good condition.

The barrel ID is 14mm. Since I'm just starting out, I only have a set of cheap aliexpress mainspring winders, the ones labeled for specific movements. The largest winder in my set (for the ETA 7750) is an 11mm ID, quite a bit smaller than the barrel.

Would it be okay to use that winder on this spring? Being new to this, I have no idea if the spring would put up with that much diameter shrink without consequences...

Given that this is likely an original 45yo spring that's sitting in dried grease, I don't think I can just leave the barrel closed and unserviced. My other alternatives seem to be to try a hand-wind and probably end up damaging the spring; getting a new close-match replacement such as the GR5599DB from cousinsuk; or cry and buy the $2,000 Bergeon winder set, and just commit to the hobby fully. Any other alternatives I've missed?

[mikepilk]

You could hand wind. Once you get the knack it's not too difficult. 

Or you could use one of your winders and cut a slot in a washer with a hole of about 13mm - see the following

(you can also use perspex in place of the washer)

 

[Neverenoughwatches]

4 hours ago, danderson said:

I'm working on my first pocketwatch, which is a Molnija 3602 movement. I successfully took the movement apart all the way, except that I haven't yet opened the mainspring barrel and extracted the spring. Given the condition of the rest of the movement, I certainly need to do so to clean and re-lubricate, but my concern is that I'm not sure how to reassemble it when I'm done. Being from a defunct soviet factory, there doesn't seem to be any NOS for this spring, and while I could search for a close enough replacement, I would like to try and reuse the original parts if they're in good condition.

The barrel ID is 14mm. Since I'm just starting out, I only have a set of cheap aliexpress mainspring winders, the ones labeled for specific movements. The largest winder in my set (for the ETA 7750) is an 11mm ID, quite a bit smaller than the barrel.

Would it be okay to use that winder on this spring? Being new to this, I have no idea if the spring would put up with that much diameter shrink without consequences...

Given that this is likely an original 45yo spring that's sitting in dried grease, I don't think I can just leave the barrel closed and unserviced. My other alternatives seem to be to try a hand-wind and probably end up damaging the spring; getting a new close-match replacement such as the GR5599DB from cousinsuk; or cry and buy the $2,000 Bergeon winder set, and just commit to the hobby fully. Any other alternatives I've missed?

I would think the spring will not fit inside a winder 3mm undersize of the barrel If you did manage to get it all in you probably wont be able to push it out again. I wouldnt risk it. But hand winding in, i do it when i have to, so do others . There is a chance that you will kink or cone the spring putting it back in, you may be lucky its a good sized barrel. Other than that, take off the barrel lid and rinse it upside down in your US, additionally some hand cleaning in a pot of benzine and a small artists paintbrush will remove some of the dirt and old grease. Its possible to also wind up the coils inside the barrel to get inbetween them very fiddly but doable in a pinch. 

[rehajm]

I second the go at the hand wind. Try with a donor first if you’re uncertain…and re winders- Cousins and the GR index are your friend- that’s a lot of new springs before the winders pay off

[Paul80]

You can buy the Bergeon winders individually to add to your Chinese set one at a time as you need them, 50-60 pound a go is a lot better than dropping 2 grand only to find you only use a few of the whole set.  Assuming Bergeon do a 14mm winder that is

[danderson]

Thanks for the advice! I opened the barrel and extracted the spring today. It seems to be in decent condition for its age, so after cleaning I'll try to wind it back in by hand, and if that fails, well there's always GR... And once I get my 3D printers back up and running, I might give the DIY options a go too, that could be quite interesting!

10 hours ago, Paul80 said:

You can buy the Bergeon winders individually to add to your Chinese set one at a time as you need them, 50-60 pound a go is a lot better than dropping 2 grand only to find you only use a few of the whole set.  Assuming Bergeon do a 14mm winder that is

I'm tempted, but on the other hand it's still a lot of money for an amateur starting out! Especially if I later decide I like wristwatches more, and never need a giant barrel winder again. I think I'll try to stick it out for a bit with hand winding and replacement springs, and see how far that gets me. If this does turn out to be a long-term interest, well, then a few grand over many years isn't completely indefensible

Thanks again for the wisdom!

[Umair]

Hi. Can you tell how the hand winding went. I am looking forward to servicing a 3602 as my first project and am concerned about everything really but particularly the mainspring. 

[RichardHarris123]

As pointed out earlier in the post, you have nothing to lose by hand winding, if it goes wrong, buy a new spring.