A Hairspring Puzzle.

[cdjswiss]

When removing the hairspring for the fourth time from the balance of an IWC cal 64T my fingers twitched and inner coil became distorted as shown. The collet is twisted and this I can correct, but to restore the first turn I am at a loss.

 

 

I opened Fried Chapter 4 BENT HAIRSPRINGS to refreshed my memory on the rules for locating the bend and correcting it.

I also re-viewed Mark's recent videos on repairing hairspring damage.

 

This has worked well in the past when the bends were in an outer coil or the overcoil, but this time I am stumped (a cricketing term for US readers). I cannot even decide if the trouble is due to an outer or inner bend. Can anyone suggest how to correct this damage?

Edited December 25, 2014 by cdjswiss

[Geo]

You have a bit of a Chinese puzzle there CDJ.

Would it be possible to Pin down the outer coil onto a piece of cork that is secured to your bench or in a vice, then descend the spring upwards holding it with tweezers by the first coil immediately above where the coil exits the collet. If you could do that, you might have enough room to slide the collet back under the troublesome coil using tweezers in you other hand. If you could do that you would then be able to re-adjust any damage caused as per Marks guidance.

This is not something I have done, but only a suggestion.

[cdjswiss]

Thanks Geo, but have you read the photo correctly? I have my problems with it but what I see is that the collet is twisted and so I must twist back the spring just where it exits the collet. But then the first turn comes around and touches the second turn after 90 degrees. both turns are in the same flat plane. So according to Fried if this is an inward bend it has to be corrected 90 deg towards the collet from the least space. That puts the correction at the collet hole. But I have not had any success by bending the spring at this point. So maybe it is an outward bend that should be corrected 90 deg towards the collet from the largest space? But at this point the curvature seems to be good. That's my problem.

The overcoil also needs reshaping but with my set of overrcoil tweezers that is relatively easy.

I have some spare hairsprings and one of those is now in the movement and ticking. But in the end I shall get this one back into good shape.

[Geo]

Sorry, I thought the inner coil was tangled in the centre rather than just distorted.

[jaycey]

Unless i'm looking at this wrong then I would start at the 7 o'clock position on the last inner coil. Hold with tweezers at that point and very gently nudge towards the centre with another pair of tweezers. from there I would gradually work my way around to the 9 o'clock position doing the same.

This should take the pressure off the problem between the 3 o'clock & 5 o'clock position.

 

May have to tweek the terminal centre curve to bring the collet back to centre.

Edited December 25, 2014 by jaycey

[Lawson]

Hey CDJ,

 

It looks a little confusing because there are two axis of trouble here.

 

Firstly mate, I would highly recommend cleaning the hairspring, as all the dirty is not going to help you isolate the exact points of contact you'll need to make.  It is blurring the silhouette of the coils ... much like military camo breaks up the outline of an object.

 

I would recommend the Y-Axis first.  Get the collet back to level with the coils, then you'll have a much better idea of pin-pointing the X-Axis correction/s, and the amount of X-Axis correction needed.

 

I've marked the point I consider to the be manipulation point for the Y-Axis correction to the collet.

 

Next look at the coils, and you'll see they are uniform (orange lines) until they reach the 4 o'clock mark, and then the uniformity ends.  Now this point may change once you get the collet back in correct alignment, but hopefully you can get the gist what I'm getting at.  Gentle stroking inwards from this point and watch for the uniformity to regain after each stroke.

 

 

Also there is wisdom in hearing others advise and opinions ... if there is no rush on the fix, wait for others to chime in, and perhaps critique my assessment as well.

Edited December 26, 2014 by Lawson

[cdjswiss]

Many thanks for these suggestions. This is a most useful aspect of the forum.

 

I shall give it yet another rinse in Bergeon one dip, but some of the dirt appears to be baked on. If that doesn't clean it up I shall try one of the ammonia based cocktails in a jar in the ultrasonic bath. That takes the oxide off brass and should do the job and I shall have a bright shiny collet!

 

I had been wondering about working backwards towards the collet and will give this a go. But first to straighten the collet itself. For this I have already made a little jig and may have to use my micro-manipulator (the old man's steady hand).

[cdjswiss]

f y i this is my micro-manipulator

 

[Geo]

f y i this is my micro-manipulator

 

manipulator.jpg

Ooooo, I like that!

What was that designed for manipulating?

[Lawson]

That's it ... we gotta rename you "Mr Cool Tools" B)

 

I'm jealous, that thing is awesomeness!!

[cdjswiss]

Ooooo, I like that!

What was that designed for manipulating?

 

No idea what it was designed for. The bent needle is my addition. The collet is for a 0.6 mm needle or something; perhaps for early medical in-vitro tricks? I found it on eBay. The modern motor driven digital ones cost 20 times the $200 that I paid for this rare mechanical version.

.

But I digress. Lawson you saved that hairspring. The recipe that you gave to me worked perfectly, what an eye you have for hairspring correction, even dirty ones!  When I have re-shaped the overcoil and cleaned again I shall post another photo.

[cdjswiss]

After lots of bending and stroking - not yet perfect but within easy reach of the final shape.

 

 

Thanks again Lawson - more cleaning needed!!

[Geo]

Very well done CDJ, I look forward to seeing the finished item and functioning watch.:-)

[Geo]

I should have asked, did you actually use the manipulator or was it all done with tweezers?

[Lawson]

Ahhh, t'is a thing a beauty CDJ.  A most excellent job my friend.

[cdjswiss]

I should have asked, did you actually use the manipulator or was it all done with tweezers?

Both , but mainly using newly dressed short tweezers. It's important, as Fried says, to use short tweezers - less wobble. I bought an expensive used set from Otto Frei and have found it a worthwhile investment.