Fusee Hair Spring

[Mitch]

A little help please from a newbie. I have just purchased a complete later 1800's Fusee pocket watch but it doesn't run, (it was sold as spares or repair).

Everything seems "free" and once I have removed the Balance if I manually move the Lever I can see the Escape Wheel move to the next position.

The balance rotates fairly freely but doesn't swing backwards and forwards, it just stops.

If I look side-on at the Hair Spring it seems tilted over, it's certainly not parallel with the Balance Wheel. With the Balance Cock removed, I can see the Hair Spring is compressed on one side, (see the attached picture).

My thought is that this Hair Spring doesn't belong to this watch, it seems to have too many turns to fit in the space between the Collect and the anchor point for the outside of the spring.

At the moment I'm assuming that it's just the Hair Spring thats not right and not a case where someone has just put a complete new Balance in from another watch.......

So does this sound like a reasonable assumption?

If so is it "the done thing" to shorten/reduce the number of turns on the Hair Spring until it sits flat and parallel to the Balance Wheel?, (or, as I suspect, am I being over simplistic....)

 

[JohnR725]

If you are really new to watch repair you might want to set this aside until you get a little more experience. Visually the hairspring looks right for the size. So image attached is one of mine as you can see the hairspring is about the right size. Notice when they're pinned to the plate there never pinned at the end. Then you're right it should be centered better and definitely parallel to the plate.

So shortening the hairspring to fix the problem will just add new problems like the watch will never keep time.

So ideally to learn to play  with hairsprings  it would be nice to have Practice hairsprings to practice with. Something not on a watch if you destroy it nobody cares. If you practice on your practice watch is the possibility it will never run ever again. This is why I usually urge find something else to practice on until you get a feel for what you're doing. But typically on this group everyone says jump in and work on the watch you have so I'm going to assume that's what you want to do.

So if we assume the balance and the hairspring is right for watch all you have to do is bend the hairspring wherever it's bent putting it back to wherever it's supposed to be sounds easy it will take a lifetime to learn that. Then the reason I am assuming they hairspring and balance is correct is that these watches are hand finished and I think basically could be considered hand made interchanging balance wheels and hairsprings can happen but probably didn't.

Then we need a better description of this sentence "The balance rotates fairly freely but doesn't swing backwards and forwards, it just stops. "?  If you rotate the balance wheel one turn in any direction let go Does it rotate back in the direction it came from? So even if the hairspring isn't perfect if you can get the balance wheel to oscillate backwards and forwards slowly coming to a stop without any energy coming from the watch then that's good. If the balance wheel rotated just stops the hairspring is putting too much pressure and you'll have to take care of.

 

[matabog]

take out the balance and hs and see If the hs is centered and paralel to the balance wheel.

If all ok then put the Back and manipulate the hs at the stud so that the last coil will seat centered in-between the regulator pins.

[Mitch]

@JohnR725.  Thanks for the guidance. I have decided to take your advice and not to "mess" with the hairspring. I'm going on holiday for a few weeks and on my return will strip the watch down, clean it and see if I can see any other issues.

Being over 100 years old I don't want to do any permanent damage, so I'm going to take things slowly and carefully.

 

@matabog. I'll try what you suggest on my return.

 

[matabog]

You do realize thoose answers contradict eachother

Edited September 13, 2016 by matabog

[clockboy]

It could be (looking at the pics) the spring has been pulled to far into the end collet. There is to much extra spring after the collet which gives me the suspicion that a previous watchmaker./tinkerer has had a fiddle. However the spring looks in good condition. Good magnification will be needed to see what is amiss.