Pressing down on Barrel Bridge starts watch working

[PeterTheRussianEnthusiast]

Hello Everyone, 

I'm looking forward to getting acquainted with you all as I dive into watchmaking and collecting again after a little hiatus of a couple of years. For those who saw my introduction post, I am a keen russian watch collector and I'm tinkering with watchmaking after having done a couple of online courses several years ago. 

I have in my collection a Poljot watch with a 2409 movement. It wasn't ticking and to be honest I can't remember if I bought it that way or not. Anyway, with all this extra time on my hands at the moment, I've been watching a lot of WR videos and it has reignited my passion for watch repairs. 

I took the 2409 apart and gave it a good service. I have the watch back together and as soon as I inserted the balance the watch started ticking again. Great! It ticked for about 40seconds or so with some noticeable missed click and then stopped. Interestingly, I noticed that the pressing down on the barrel bridge got the watch ticking again. I though perhaps i didn't tighten the screws down properly so I tried resetting the barrel bridge and barrel and still the same problem. I have a several spare parts movement so I tried using a different mainspring barrel thinking perhaps there was something wrong with the mainspring? That made it work a little longer (2 minutes or so) but still the problem persisted and pressing gently down on the barrel bridge kick started the watch again.

I'm going to strip down the watch completely and inspect every part more closely for any sign of defects. Any ideas what may be going on here? Where should i focus my attention?

Thanks again and I look forward to participating in this community. 

 

[Nucejoe]

Check the minute wheel, it may rub on the barrel lid if wobbles.

[watchweasol]

Hi Apart from Nucejoe's  comment check that the arbour and barrel bearings are not worn causing the barrel to tilt under power.         Tech shhet attached for your interest.

Poljot 2409.pdf

[PeterTheRussianEnthusiast]

Thank you NuceJoe, I will keep that in mind, but at this stage I've yet to install the minute wheel.

Watchweasol, thank you so much for that PDF, it really is great. That makes a lot of sense. I changed the whole barrel assembly including the arbour when I swapped out the mainspring. It did work better so perhaps the spare movement also had a problem(not sure of its history). I'll take a close look under a microscope if full light tomorrow morning and report what i see. 

Thanks, you've been so helpful already. I'm glad I found this site. 

 

[jdrichard]

Thank you NuceJoe, I will keep that in mind, but at this stage I've yet to install the minute wheel.
Watchweasol, thank you so much for that PDF, it really is great. That makes a lot of sense. I changed the whole barrel assembly including the arbour when I swapped out the mainspring. It did work better so perhaps the spare movement also had a problem(not sure of its history). I'll take a close look under a microscope if full light tomorrow morning and report what i see. 
Thanks, you've been so helpful already. I'm glad I found this site. 
 

I would look at the leaves of the center wheel pinion. Could be a small piece of dirt that could cause it to stop. Clean all the pinion leaves carefully.


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[anilv]

CHeck that the barrel does not tilt when installed. If it does the holes in the barrel bridge or mainplate could be worn slightly, that is why it works when you press down the barrel bridge.

Anilv

[PeterTheRussianEnthusiast]

Thanks so much for all the great advice.

@anilv I think you may have hit bingo with this comment " barrel bridge or mainplate could be worn slightly, that is why it works when you press down the barrel bridge." 

I did notice the mainplate had almost a rut scratched into one area, and I guess subconsciously that's what made me press on the barrel bridge suspecting something might have been amiss here. I have a spare mainplate so I will try that one and see how it performs. Any ideas what would cause that amount of wear? I guess poor servicing history?

Thanks JDRichard, I will take a close look at that as well. 

[anilv]

probably wear and tear. Problem with russian watches is that while the movements are good, the cases are pathetic, offering little in the way of protecton from humidity and dust. Hence they require regular servicing.

Anilv

[PeterTheRussianEnthusiast]

Thanks again Anilv, I agree. I watched a video the other day of someone restoring an old omega seamaster. It looked like that watch had been rolling around in someone's toolkit for years. I was surprised to see how well the case did it's job because the dial and movement where in amazing condition. I remembered thinking that would not be the outcome if that watch had been in a Raketa or Pobeda case. Having said that, I do like the Vostok Amphibia case design, I find those to be very well engineered for diving. 

[PeterTheRussianEnthusiast]

@anilv Thanks again Anilv, I replaced the barrel bridge and all good now. This is what i meant about the rut on the barrel bridge. 

 

 

[anilv]

Glad it worked out Peter, that's a typical sign of worn barrel pivots.

Anilv

[rodabod]

Just to pass more credit where it’s due: then third comment from WW suggests checking the barrel arbor bearings as these cause tilt due to side-shake.