Hairspring Stud Question

[rattandsonwatchmakers]

_{how would you explain this....a movement has been cleaned and oiled...fresh mainspring....however no balance motion...loosen the screw holding the hairspring stud to the balance cock and the balance takes off and the watch runs fine....tighten the screw and the balance stops...loosen it and the watch takes off again...at no time is the hairspring rubbing against the balance cock...why?}

Edited May 2, 2014 by rattandsonwatchmakers

[WillFly]

Might the turning of the screw give a subtle alteration to the inclination of the hairspring which starts and stops it from functioning correctly?

 

I'm certainly no expert - just trying to imagine what the action of the screw tightening/loosening might have from a logical viewpoint...

[autowind]

Well that`s a dilly of a pickle as we say,  logically,  something is touching the balance wheel,  if the hairspring was touching the underside of the balance cock or the centre wheel then the balance would most likely still run,  although not very well.  I could only suggest very close examination whilst tightening and loosening the stud to see if anything is revealed,  not very helpful I know,  Mark will have the best ideas once he spots this thread.

[Geo]

Sounds like dirt or congealed oil in the balance jewels particularly if the jewels are not of the incabloc type. I have had the same problem with a vintage Rolex.

There are probably other reasons that Mark will undoubtably be able to shed light on.

[Mark]

Looking at the spring side on - is it completely flat ? Is the stud touching the balance at all?

Sent from my iPhone using Tapatalk

[Shahbaz]

Have you checked the stud insertion? It may not be inserted far enough, and when you tighten the screw, it may twist and force the hair spring up or down, enough to jamb the balance pivots, especially, as Geo mentioned, dirty jewel hole.

Regards,

Shahbaz

[Geo]

Ignore my first answer, I misread the question and thought it was the screw that held the cock down.

Did you get to the bottom of the problem?

[Mark]

I have had, on occasion, watches where the stud has been replaced by a non-original part and does not fit the hole exactly. This can take some tweaking to get right - that's why I asked if the hairspring was sitting straight when the screw was tight because if the stud is incorrect then it will adjust the springs position depending on wether the stud is secure or not (naturally).

 

But also is the spring attached to the stud correctly? The stud (usually) will need to be pointing upwards at 90 degrees from the spring once the taper pin tightened in the stud. I have seen these poorly attached before where the stud is at a funny angle, again causing the hairspring to be at an angle. Loosening the stud will cause the spring to change position in this case also.

 

It is in cases like this where lots of practice with hairspring adjusting will be your saviour. 

 

A word of encouragement for watch repairers with less experience in this area: I cannot emphasise enough how important it is to get as many scrap movements as you can and strip down the balance components - study them and burn into your memory how they should be - that way when you see a watch with a faulty escapement or balance you will instinctively know what looks out of place. The key word is practice.

 

Watch repairing is like learning to play a musical instrument in that respect.

[dbals]

Going through this right now with several "complete" russian movements I got off the bay for a few bucks.  I have complete in quotes because two were missing jewels and two have hairsprings that look like the went through a war and lost.  

 

I'll got one working again and finished striping and putting the second together but can't seem to get the hairspring to move when screwed into the balance cock.  Will check again in the next few evenings-  Thanks for the insight.

 

 

Daniel 

[rattandsonwatchmakers]

upon close observation i notices that the stud in slightly smaller then the hole in the balance...causing is to wobble around..when the screw is tightened it binds.....just as you made mention

Edited May 7, 2014 by rattandsonwatchmakers