Bulova 11AF Will Not Run

[Berwolf]

Link worked for me, did not disassemble anything yet.  Thanks for the quick feedback. Started looking deeper into the coil and could see it was slightly bent where it attached to the bridge so I straightened it while assembled, it is now running but with very low amplitude. I can see also the balance spring is not perfectly concentric when in the pivot one side of the coils are closer to each other than the other. What should be my next steps?

[Nucejoe]

 We need to see the coil,  detach the balance complete from the cock, show a clear close up top view of the coil, one from the side too. 

 You would need high magnification to show the pivots, putting a loup in front your phone lenz often works good enough to show the pivots. 

Rgds

 

[Berwolf]

40 minutes ago, Nucejoe said:

 We need to see the coil,  detach the balance complete from the cock, show a clear close up top view of the coil, one from the side too. 

 You would need high magnification to show the pivots, putting a loup in front your phone lenz often works good enough to show the pivots. 

Rgds

 

To remove the balance, just undo the screw from the cock and take the coil out of the regulator pins? Can I just take this off or does anything need to be documented or marked for reassembly?

Here is a picture where you can see the coils that are not concentric. 

[Nucejoe]

1 hour ago, Berwolf said:

you can see the coils that are not concentric. 

 A flat but not concentric coil doesn't stop the watch , at worst makes it beat faster. Hairspring rubbing on balance spokes or underside of the cock can grind the oscilator to a hault.

This terminal curve can benefit from minor adjustment and coil sorted out to concentric. Sure way to check pivots is under high magnification so best to seperate the oscilator from the cock, no need to mark or document anything for what your about to do now.

Can you show the pallete lock on escape teeth?  

Good luck 

 

 

 

 

 

[Berwolf]

Here are a few pictures with the balance spring disassembled and the pivots.  I think it all looks ok. I reassembled the balance to the bridge and put it back together and it is running better.  Don't have a timegrapher so leaving it running to see how it keeps time now. Thanks for everyone's help!

 

[ManSkirtBrew]

The hairspring looks pretty well twisted right at the stud, which is something I've seen on several watches I've done (and has been the easiest to fix of the hairspring defects I've dealt with).

That would cause the hairspring to twist relative to the plane of the balance wheel, possibly rubbing on it or the cock and stopping it.

Can we see the balance complete installed directly from the side and front? Your hairspring should be dead parallel to the balance wheel and the balance cock.

[Nucejoe]

Is first picture showing balance in perfect vertical position?    if so the coil isn't perfectly  parrallel with the balance rim, which means coil might have or is rubbing on spokes or underside of the cock when it expands while

breathing.

Terminal curve needs sorting. 

Should look like this,

https://images.squarespace-cdn.com/content/v1/57eb39332e69cfdc14c1d642/1493346917160-F9KK4KMEUYAPOZLH8XG7/image-asset.jpeg?format=1500w

Notice stud stands prependicular to the coil.

Edited December 15, 2023 by Nucejoe

[JohnR725]

2 hours ago, ManSkirtBrew said:

The hairspring looks pretty well twisted right at the stud, which is something I've seen on several watches I've done (and has been the easiest to fix of the hairspring defects I've dealt with).

That would cause the hairspring to twist relative to the plane of the balance wheel, possibly rubbing on it or the cock and stopping it.

Can we see the balance complete installed directly from the side and front? Your hairspring should be dead parallel to the balance wheel and the balance cock.

this is why and I thought I already mentioned this maybe it was in another discussion it's always best to look at the hairspring in the watch where the problem is. When you remove the balance wheel with hairspring as you can see the hairspring looks fine obviously we don't have a problem except it's out of the watch and that's not where the problem is.

So yes the stud does look like it's twisted but it's hard to tell it would be best if the whole thing was back in the watch where we can look at it carefully and see if it is bent. So balance wheel back in the watch and you look carefully and grasping now that you're bent at the stud which is a classic place to bend hairsprings.

So classically removing balance completes from watch is they will get bent in a variety of locations the stud is the most popular place followed by the regulator pins and in other places we don't want to talk about because your hairspring looked fine other than the stud.

[Berwolf]

Well disaster struck last night on the hair spring. I took it back out and was working on it a bit on some rodico. Part of the hairspring stuck to the rodico when I was going to reassemble it and it got tangled and I was unable to save it. I have another movement on order so I can take the balance from it. 

[CYCLOPS]

I see burs or raised metal on the underside of the bridge also, this can tip the balance bridge too far one way or another creating too much or no inshake, old timers used to do this on pocket watches....you can find these movements easily for parts