Mainspring

[chaplin37]

I pretty much know the answer to this question but wanted to get a second opinion. I have an as 1580 movement and when i wind the watch the mainspring gets tight but never to the point that its stops winding now it probably needs a new mainspring, but i bought a donor movement to and that movement mainspring is acting the same. I looked at it in the barrel and it doesnt look broken. So my guess is i need a new mainspring. Also when i do wind it it the balance starts to move a little but doesnt ever start.

[gerene]

Hello Chaplin37,

an AS 1580 is an automatic winder. The mainspring in an automatic winder is not hooked up to the barrel but has a stiff, short length of spring fastened to the outer end of the mainspring to act as a slipping clutch. Once the mainspring is wound, the stiffer spring slips around the inside wall of the barrel. This arangement prevents damage when the spring is fully wound and the automatic winding mechanism continues to wind the spring.
So, yes, you can keep on winding and it will not get to the point where it stops winding even when fully wound.
The fact that the balance does not start can be the spring, the train or the escapement… Did you clean and oil the movement?

Jan

[chaplin37]

Thanks Jan for the information, when i do wind it i can see through the little cut out on the barrel and the end that is touching the barrel is moving in circles around it, is that normal? I cleaned and oiled everything and it looks good, when i do wind the watch the balance starts to look like its going to engage and move but its end up not. Not sure if that makes sense, Im going to take a video of the movement and post it.

[gerene]

I would start by trying to pinpoint the problem to either the mainspring, the gear train or the escapement.

Take out the balance and the pallet fork. Wind the mainspring a few turns and see if the gear train is running normally and comes to a gradual stop followed by a recoil. If that is the case, your problem most likely is in the escapement. If not it is either the mainspring or the gear train.

Does the balance start after a little shake, or doesn’t it start at all? If it starts after shaking the watch is out of beat.

Jan

[chaplin37]

Thank you Jan, it was actually the gear train that was the problem it now is running. One more question for you is that the watch is running good and keeping time. I placed the watch and all 4 positions to see if it stays running and it does. However, when i wear it after a while the second hand will stop in the same exact spot. I checked to see if it is rubbing against the hands and it is not. Not sure what is causing this to stop on the same spot everytime.

[gerene]

If it is stopping at exactly the same spot everytime, then more than likely the seconds hand will bind with either the crystal or the minute hand. You might want to check if the hands are all parallel with the dial. It might be hard to see if the hand binds with the crystal, good luck!

Jan

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