Movement AS960 / Balance does not move freely

[BlueHarp]

Hello,

I got an old watch equipped with a Schild caliber, the AS 960, which was made in the 1930s. The gears turn freely, but the balance wheel doesn' oscillate. It looks as if somehing was rubbing against it, whatever the position. The balance staff looks a little "short" (maybe the pivots are worn out?).

Any idea? Here are a few pictures.

[oldhippy]

You need to remove the balance complete and look at the balance staff. I expect it is broken as I see it is not shockproof.  

[Nucejoe]

42 minutes ago, BlueHarp said:

 whatever the position. The balance staff looks a little "short" (maybe the pivots are worn out?).

As long as short pivots stay in jewel holes, balance can oscilate in vertical position .

Does balance somewhat turn, but don't do a decent oscillation or is it dead stop?  Does it tend to turn if you tweak/encourage it? 

Zero end shake stops balance.

Check side and end shakes.

Check If pivots  stay in the " SETTING'S HOUSING HOLE"   in which case balance rim ought to observably tilt.

If above tests didn't conclusively reveal a fault, you should remove the balance for a visual inspection.

In case balance turns but escapement doesn't oscilate it,  it can also be missing impulse jewel.

Balance rim seems to be rubbing on fork cock in face done position.

 

 

Edited September 17, 2024 by Nucejoe
Add foot note and spelling

[BlueHarp]

1 hour ago, oldhippy said:

You need to remove the balance complete and look at the balance staff. I expect it is broken as I see it is not shockproof.  

@oldhippy I don't think any pivot is broken. Here are additional pictures (not very clear, unfortunately).

@Nucejoe I will do that right now. By the way, this is a cylinder escapement.

[oldhippy]

That pivot is damaged. Cylinders have to be perfect and they extremely hard are brittle, Have you checked the pivot holes.  What's the other end like.  

[Nucejoe]

Pix are unclear, highly trust OH diag, 

namely " damaged pivot" in spite of which ,  heres a test just to make sure.

-Remove the fork cock and fork itself.

-Install the BALANCE & BALANCE COCK,  back on the mainplate. 

-Check end shake on staff (  the free end "axial" play on staff )

-Check  if then balance turns freely.

Note,  end play on staff,  if Zero !        loosen the cock screw to create some end play.

Test for balance free oscillation.

Good luck

 

 

 

 

[oldhippy]

I magnified  the picture right up. You can do it in microsoft paint which is with windows 7 which I use. I don't like windows 10 its a hog. 

[BlueHarp]

I have removed the cylinder escapement, then put the balance wheel on the plate, and it oscillates very well. I guess that the problem might come from the escapement itself????

[nevenbekriev]

See, the cylindre escapement is not free oscillating escapement. The balance is never free and friction in the place where the cylindre wheel teeth touch the cylinder is present all the time. You need to perfectly clean and lubricate at least the escapement parts. The best lubrication I have found for cylinders is Moebius 8200 grease. Just a little quantity on the traces which the teeth have left on the internal and outside surface of cylinder. The down side pivot looks bent. This is no good, but if the free oscillations test is OK, then probably the movement will be able to work.

[Nucejoe]

3 hours ago, BlueHarp said:

I have removed the cylinder escapement, then put the balance wheel on the plate, and it oscillates very well. I guess that the problem might come from the escapement itself????

So pivots are good. 

 In the second pic you posted, lower setting seems moved a bit, possibly done by previous guy , to adjust for end shake, which could have thrown escape teeth and balance out of alignment. 

A side view of the balance and escape teeth might help  spot misalignment.

Oscilating the balance YOU  might see whats hitting what . 

As neven says, escapement if dry, can refuse to run, escape wheel might be the issue, broken/ bent pivot or lack of end shake on escape arbour.

 

Edited September 17, 2024 by Nucejoe
Add foot note and spelling

[Nucejoe]

5 hours ago, nevenbekriev said:

See, the cylindre escapement is not free oscillating escapement. The balance is never free and friction in the place where the cylindre wheel teeth touch the cylinder is present all the time. You need to perfectly clean and lubricate at least the escapement parts. The best lubrication I have found for cylinders is Moebius 8200 grease. Just a little quantity on the traces which the teeth have left on the internal and outside surface of cylinder. The down side pivot looks bent. This is no good, but if the free oscillations test is OK, then probably the movement will be able to work.

 I guess cylinder escapement is more responsive to lubrication than Swiss lever .  I didn't know that. Have only one pocket watch with cylinder escapement, must have not been serviced in past thirty years, but kicks off and runs strong with little wind which kind of misled me.

 

 

 

8 hours ago, oldhippy said:

I magnified  the picture right up. You can do it in microsoft paint which is with windows 7 which I use. I don't like windows 10 its a hog. 

Gosh ,  OH I live in stone age when it comes to computer stuff.  learned forturan specifically to do complex numerical  calculation just  for nuclear reactions.

First I heard of windows, thought its about glass windows in buildings.  

 

 

 

[KarlvonKoln]

3 hours ago, Nucejoe said:

I guess cylinder escapement is more responsive to lubrication than Swiss lever .  I didn't know that. Have only one pocket watch with cylinder escapement, must have not been serviced in past thirty years, but kicks off and runs strong with little wind which kind of misled me.

Lube!  Cylinder escapements need lube!  All the old watchmaker's tomes will corroborate this.  They are a "friction rest" escapement. A tooth of the escape wheel will always *rest* against the cylinder wall as it turns, creating either engaging or disengaging *friction* depending on which way it oscillates.  Neven is right; 8200 oil is good.  One of the older books I borrowed did specify that, by the nature of their design, a cylinder escapement should be serviced every year - NOT every five - due to enduring greater friction than a lever escapement.  Particular attention should be given to the cylinder wall, inner and outer, to see if there are any deep scrapes.  Check escape wheel teeth for burs, and make certain that all parts are as clean as can be. The method of lubrication was given thus: one should place a smear of oil on the tip of every other tooth of the escape wheel.  The pivots are oiled like any other watch. Likewise with all other parts.

I have worked on several cylinder escapements, and four such watches are my own and one is my wife's.  They may need yearly attention but at least they are very easy to work on.  If you keep them clean and oil them right they will last very well.  I also possess the special punches and stumps, and can get uncut cylinders and tampons with pivots, so if you ever need a site for parts, send me a PM.

Edited September 18, 2024 by KarlvonKoln

[oldhippy]

With clock cylinder escapements I would oil every other escape tooth then let the power do the work it will spread the oil to each tooth. You also need to make sure the cylinder has no wear on it around the entry and exit part of the cylinder as the can cause poor action and cause stoppage.   

[BlueHarp]

Thank you all for your explanations. It seems that repairing that kind of watch is beyond my ability for now. I must focus on less complicated issues. And we have plenty of choice in that area 

[nevenbekriev]

See, cylinders are actually less complicated. They just have pecularities. Modern watchmakers are frightened by them and claim that they are hard to work on, but it is because they are not prepared and familiar with cylinders