Aw, Geez.....

[GeneJockey]

I picked up another watch from Ebay, a movement and case I'd been wanting for a while. Got it for cheap because it was 'wound tight'. Opened it up, checked first to see if the balance staff was broken. Nope! Hmmm. So why doesn't it run?

So, I look closer at the balance. Something not quite right....



Well, THERE'S your problem!!! I took off the balance cock for a better look. Oy. What a mess!



When I got it, the regulator was pushed all the way to Slow. Looking at the hairpspring, I noted that even with the stud removed from the cock, several coils are touching. Lifting the stud, I noticed that these coils stick to each other.

So here's my hypothesis: guy gets watch. Watch runs fast, because coils are touching. Guy swings regulator over to 'Slow', but hairspring is trapped by regulator pins. Hairspring gets crushed between regulator and stud. Watch stops. Guy tosses watch in drawer.

Time passes, and the watch finds its way to me.

I guess this will test my ability to true a hairspring. Well, I'm nothing if not foolishly overconfident!

 

[karlmansson]

Sounds like a reasonable hypothesis!

I had a similar problem with a 1930s Omega without a safety regulator. Someone before me had tried to regulate the watch all the way to Slow with the spring on the inside of the pins. The result was a sharp bend, sort of like an S shape, close to the stud. The metal had become stressed enough that it snapped when I tried to straighten the spring. It left be with 7mm less hairspring. I added some timing washers to the balance to compensate but the studding point is permanently altered so positional variation is going to be off no matter what I do.

My take home message is: try your utmost not to break a section of spring off! There's more to the hairspring than just length and restudding a shorter one will alter the geometry of the oscillator as a whole. Your bend do not look too sharp and I think you will be fine!

Best of luck!

 

[GeneJockey]

Thanks! As I look at it, I see 3 bends that need to be corrected. First, the 90 degree bend at the stud. That's the one that worries me most, because it's a sharp bend, and I don't want fatigued metal to break.

The second is the curve where it's bowed outwards. That's more gradual, so it's less worrisome.

The third is the transition from the overcoil to the regulator sweep. That's the most straightforward, I think. And I'd note that the curve between that and the second bend actually looks correct for the regulator sweep.

Mind you, the very first thing is to get the spring CLEAN, so it doesn't stick together!

 

[Nedredbeard]

If it were a blue hairspring it would be a lot more risky. The later white springs can handle a bit more abuse before they snap. I wouldnt worry too much about it, they made a ton of those movements. If you break the spring or smash it with a hammer in frustration, send me a pm i've got lots of them. Looks like you're in ca too so, no prob.

 

[karlmansson]

Use No 7 tweezers if you have them, if not, just fine hairspring tweezers held from directly above. The least stressful way for the metal is to hold the spring like that and then stroke it with a polished needle from the tweezers and outwards. Start a mm or so from the tweezers to make the bend smooth.

Hopefully someone else will have input on this as I've never tried it but something tells me that you may be better off annealing the sharp bend than risking breaking it. You would do that by heating the terminal end and holding the spring with heavy (but well dressed) tweezers close to where you are heating, to act as
A heat sink and prevent you from annealing more spring than you want, the stud may be an issue and ideally you would remove it but I can see how that would be hard...
Other members, annealing a sharp bend in a hairspring close to the stud and on the far end of the regulator sweep. Yay or nay?

 

[Nedredbeard]

never apply heat to any hairspring. it changes the structure of the metal and will not run correctly, guaranteed.

 

[Skutt50]

Agree.... A heated hairspring is a lost hairspring! The spring will change in a strange way and at best you have a watch out of beat but more often way off in timing as well!

 

[karlmansson]

never apply heat to any hairspring. it changes the structure of the metal and will not run correctly, guaranteed.

That's what I figured. But my thinking was that as the heated section (provided the tweezers lead residual heat away from the body of the spring) will be outside of the active section of the hairspring it wouldn't have an impact on the functioning of the spring. Whereas a loss of length would.

A hairspring is tiny so I suppose you'd have to shield the rest of the spring in some way... But yeah, go with bending and see how it goes then. It would be cool to try some experiments on this though... This is the method that I use when I need to make a new hook on a mainspring. Anneal the final cm over and over and bend in bouts until I have a flat bend. Steel can be shaped pretty much indefinitely as long as you anneal it in between bends.