Mainspring winding tool size

[DaveL]

Another new guy question I have a 12.44 mm barrel inside dimension,should I get a 12mm winder or a 10.8 mm, thanks again

[Kalanag]

Taking the 10.8 gives the opportunity of using this winder with lots of popular movements in the future (ETA 28xx, Rolex). As long as your current movement is hand wound I would definitely purchase the 10.8. Going that narrow with an automatic spring might bend the bridle though.

[Neverenoughwatches]

9 hours ago, DaveL said:

Another new guy question I have a 12.44 mm barrel inside dimension,should I get a 12mm winder or a 10.8 mm, thanks again

Eyup Dave. I will say that I destroyed a mainspring once and also the hook on a spring winder by using a winder that was too small. If you see or suspect that the spring is becoming too tight in the winder then back off. I didnt leave enough space to release the arbor hook. Silly mistake but i did learn from it. If you do find that this happens and the hook is jammed it may be better to remove the spring from the winder from the opposite end and back it out again. This may damage the spring but better and cheaper that ruining you winder.

[VWatchie]

12 hours ago, DaveL said:

Another new guy question I have a 12.44 mm barrel inside dimension,should I get a 12mm winder or a 10.8 mm, thanks again

Mainspring winders are a complex topic. In short, to make them work really well they have to be manufactured for a specific calibre. That said, oftentimes we can get lucky that a winder for a specific calibre also works for another calibre. You'll find plenty of discussions on this topic here on WRT if you google it: site:watchrepairtalk.com mainspring winder

Anyway, I would recommend the 12mm winder. Chances are its arbor will fit the inner coil of your mainspring better. Do remember, there's no guarantee the winder will actually work with your spring unless it's specifically made for your calibre. With such a wide barrel you may want to wind it in by hand. Below is a link to a post by @nickelsilver (one of the most experienced pros on the forum) explaining how to do it.

 

[DaveL]

thanks gentlemen