Rolex movement pausing when bumped

[jdrichard]

Did a complete service on a vintage 1957 Rolex watch movement. After I ran the train following cleaning, all gears ran super smooth. Put the pallet fork back in and all good...nice snap. Then I removed the balance with hairspring and dipped it in lighter fluid to clean the roller jewel, table and mainly the hairspring. Agitated it with a air puff and finished all the work. When reinstalled, the amplitude was still poor. Had a closer look with stereo microscope and the was oil between the spring leaves. Removed the spring and cleaned it again in lighter fluid, but left it there do 1/2 hour. Did the reassembly and the watch ran with and amplitude of 200, Swing of 400 deg. Excellent! Then after 10 min, it jus stopped. Tested every thing then removed the balance and just put it back in and Bam! Worked again. Then I intentionally rocked it on my mat with small bumps and it stopped again. I then took a screwdriver and placed it under the hairspring and jogged it a bit. It again started. Then I noticed that the stud was not completely in place. Got the movement going again and slid the stud back into the slot and tightened the 2 plate retaining screws. Could this have been the problem? Watch currently running nicely. I am processing the video and will share it in an hour or so. 

[Nucejoe]

Center arbour spring shouldn't push on the said arbour's pivot,  a .01 mm tolorance is common.

How did you lube the interface between the pinion of center arbour and center jewel? 

 

[jdrichard]

 

[rodabod]

Hi JDR,

I’m not sure that your balance alone has freedom of movement. Can you install it with the movement wound-down and the pallets removed to check to oscillates freely? And presumably the end-shake and side-shake look reasonable?

A couple of other things, purely my opinion: with non-shockproof balances, I tend to be quite careful when screwing down the balance cock. If the balance isn’t visibly vibrating slightly then the pivot may not be seated in the jewel hole. So, if it’s static like in your video then I sometimes give it a nudge for confirmation. When nudging the balance wheel, I would use something light and flexible like an oiler, and not a screwdriver. 

[JohnR725]

5 hours ago, jdrichard said:

Then I noticed that the stud was not completely in place. Got the movement going again and slid the stud back into the slot and tightened the 2 plate retaining screws. Could this have been the problem?

there must've been some reason why they invented this type of stud holder. If it was to torture the watchmaker that might have been the reason but there's probably some other reason we just don't know. Because the stud slides in and also likes to slide out when you're tightening the screws all sorts of undesirable things will occur. Then if the screws are loose then that definitely would be a problem also.

how is the watch currently running?

.

[Nucejoe]

6 hours ago, JohnR725 said:

how is the watch currently running?

I keep fingers crossed.

11 hours ago, Nucejoe said:

Center arbour spring shouldn't push on the said arbour's pivot,  a .01 mm tolorance is common.

How did you lube the interface between the pinion of center arbour and center jewel? 

 

In case the issue persists( keeps stopping)  I usually remove that center arbour=sweep arbour= seconds arbour, to eliminate this most common culprit with FHF70, its pivot sits on its retaining spring, that is metal on metal, on the other side of its pinion, your have pinion&(center jewel) interface which also requires special attension in oiling. 

Easy to take out the sweep arbour, for start of elimination process.

In some versions a mini bridge was put on gears bridge, you would think that should have eliminated most relevent culprits, it actually didn't. Only FHF70 in which the minute wheel was incorporated inside ebauche solved the culprit , that version is truely a jewel, an excellent workhorse.

 

[jdrichard]

12 hours ago, JohnR725 said:

there must've been some reason why they invented this type of stud holder. If it was to torture the watchmaker that might have been the reason but there's probably some other reason we just don't know. Because the stud slides in and also likes to slide out when you're tightening the screws all sorts of undesirable things will occur. Then if the screws are loose then that definitely would be a problem also.

how is the watch currently running?

.

It seems to be running fine now but I will see if it wants to stop again in different positions. The way it would stop seemed to be dragging. I know the train is perfect as I ran the train a few times again. My thought was that the hairspring, that is now perfectly symmetrical, was rubbing in the balance arm, but I checked that with my microscope and it looks like it’s not touching. I also had a look at the roller table and jewel and they look fine as well. Will check and pray again this morning. Ran all night.  

[jdrichard]

5 hours ago, Nucejoe said:

I keep fingers crossed.

In case the issue persists( keeps stopping)  I usually remove that center arbour=sweep arbour= seconds arbour, to eliminate this most common culprit with FHF70, its pivot sits on its retaining spring, that is metal on metal, on the other side of its pinion, your have pinion&(center jewel) interface which also requires special attension in oiling. 

Easy to take out the sweep arbour, for start of elimination process.

In some versions a mini bridge was put on gears bridge, you would think that should have eliminated most relevent culprits, it actually didn't. Only FHF70 in which the minute wheel was incorporated inside ebauche solved the culprit , that version is truely a jewel, an excellent workhorse.

 

That is a great idea as the metal leaf spring pushed down on the center seconds pivot to keep it in place and I did not put any lubrication on this pivot.  Should I Lube this and with grease or oil?

[Nucejoe]

1 hour ago, jdrichard said:

That is a great idea as the metal leaf spring pushed down on the center seconds pivot to keep it in place and I did not put any lubrication on this pivot.  Should I Lube this and with grease or oil?

Hi Jd, I once put the question to @nickelsilver the oil he recommended wasn't anything special, sorry I don't remember which oil he said nor the thread the discussion was in, more importantly is to oil the pinion-jewel interface as well and above all to remove/eliminate the center arbour just to check if an issue is there, in which case I am sure you are set to polish all interfaces on the center arbour.

Judging by your video that oscilator runs perfect.

Good luck.                    Regs 

[jdrichard]

5 hours ago, Nucejoe said:

Hi Jd, I once put the question to @nickelsilver the oil he recommended wasn't anything special, sorry I don't remember which oil he said nor the thread the discussion was in, more importantly is to oil the pinion-jewel interface as well and above all to remove/eliminate the center arbour just to check if an issue is there, in which case I am sure you are set to polish all interfaces on the center arbour.

Judging by your video that oscilator runs perfect.

Good luck.                    Regs 

It is running like a dream. Cased it this morning and polished the case at the request of the owner. She is blown away, and now wants to get insurance on it.  Here are my final pics. Will let it run overnight and then regulate it.