Sudden Loss of Syncronicity...

[artphotodude]

Have run into this a few times over the years with Raketa 2609.HA movements (19-Jewel Time Only).  I have a watch in good working order that suddenly starts running fast (not like magnetized fast, just gaining 5 minutes an hour or so).  And in each case, the regulator appears to have no effect to either speed up or slow-down the watch.  In each case have also tried demagnetizing just in case that was the cause with no effect.  Any idea what might be causing this?  I don't have the issue with all of this caliber (as many have done great) or with other brands, but it has happened often enough I'm thinking I should get to the bottom of it.

Thanks for any ideas!

[AndyHull]

Check the hairspring is actually concentric and clean. Check it off the watch. Check it on the watch, by videoing it and slowing down the video. Do so when it is working and when it is erratic, and see if you can spot the change.

Possibly likely there is a problem causing the swing to drop and this is causing the oscillation to speed up or become erratic, so check the swing when fully wound and compare with when the movement speeds up. Is it still in beat when it is erratic? Is the swing >200 degrees?

Check the palette fork jewels are not loose or misaligned.

Check the barrel bushings are not badly worn. Is the barrel rubbing on the main plate or the barrel bridge?
 

Finally if nothing makes sense, swap parts with a known good movement till the problem goes away. Then when the fault goes away, take a good look at the last part you swapped.
Swap it back and prove it causes the issue. Figure out why.

[artphotodude]

2 hours ago, AndyHull said:

Check the hairspring is actually concentric and clean. Check it off the watch. Check it on the watch, by videoing it and slowing down the video. Do so when it is working and when it is erratic, and see if you can spot the change.

Possibly likely there is a problem causing the swing to drop and this is causing the oscillation to speed up or become erratic, so check the swing when fully wound and compare with when the movement speeds up. Is it still in beat when it is erratic? Is the swing >200 degrees?

Check the palette fork jewels are not loose or misaligned.

Check the barrel bushings are not badly worn. Is the barrel rubbing on the main plate or the barrel bridge?
 

Finally if nothing makes sense, swap parts with a known good movement till the problem goes away. Then when the fault goes away, take a good look at the last part you swapped.
Swap it back and prove it causes the issue. Figure out why.

Thanks so much for the info.  It might well be the Barrel Bushing, because I let all the tension out, and then wound it back up and it was considerably better.  I suspect a bit of oil or gunk went where it wasn't supposed to.

[Walsey]

Is the balance amplitude low or high?  One possibility is If the balance amplitude is very high it will begin to knock and the rate will be very fast.  If you listen to the sound of the escapement knocking will sound like galloping instead of the normal tick-tock.

[Nucejoe]

Does this happen with the watch on wrist? 

 Can be a case of  hairspring jumping out of regulator slot, its viewable  in a slow-mo vid of the regulator-hairspring,  shake the watch vigoreously before filming,  you might end up taking several vids.

It might also be a case of intermittent sticking.

Rinse the hairspring. 

Rgds

 

Edited April 7, 2023 by Nucejoe

[JohnR725]

8 hours ago, artphotodude said:

Raketa 2609.HA movements (19-Jewel Time Only)

we always like pictures here just in case we don't actually know what what you're talking about

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&&2uswk&Raketa_2609_HA

8 hours ago, artphotodude said:

Have run into this a few times over the years with Raketa 2609.HA movements (19-Jewel Time Only).  I have a watch in good working order that suddenly starts running fast (not like magnetized fast, just gaining 5 minutes an hour or so).  And in each case, the regulator appears to have no effect to either speed up or slow-down the watch.  In each case have also tried demagnetizing just in case that was the cause with no effect. 

a little more clarification perhaps? The watches running fine on your wrist or it's on your bench where exactly is it when this happens? Is it fully wound up or at the at the end of its winding etc. Then when it does speed up forever and you can never get up to slow down or it's just a temporary problem?

3 hours ago, Walsey said:

Is the balance amplitude low or high?  One possibility is If the balance amplitude is very high it will begin to knock and the rate will be very fast.  If you listen to the sound of the escapement knocking will sound like galloping instead of the normal tick-tock.

this is why I was like to see pictures of the watch were talking about this that you're describing is common with some automatic watches if the mainspring doesn't slip. But from the picture at the link above its modern automatic and we didn't have  a proper description of what was the condition of the winding of the watch at the time this occurs. 

 

[artphotodude]

So I think this is barrel-related for sure.  In each case of the Raketa's, it seemed to go away after letting the tension down by holding the click and then rewinding (seems to be keeping very good time again).  To the point up above about this happening also in automatics, I have indeed also encountered in with a Vostok automatic (new) but didn't know how to address it then and used the watch for parts since was quite inexpensive.  The current watch, while not in super shape (rather low amplitude) has been quite accurate until this event, and now seems to be back to normal (both on wrist and left laying on the table), so this appears to be signs fo just needing a full-service.  Will wear it a bit further before tearing it down for that as the case/dial work has already taken a lot of time and I'd just assume use it for a while before doing more work on it.  Thanks for all the replies!

P.S.  Here is a picture of the watch.  is a nice user as the chrome plating is super-thick on these, the bracelet is actually stainless (so very polishable) and the giant high-dome tends to catch most of the nocks - that can them be polywatched-out.