Poljot 2415 barrel bridge not sitting flat

[Myron62]

Working on a Poljot 2415 and have had various problems but help from WRT has enabled progress to be made. My latest problem is that the barrel bridge will not seat flat onto the main plate. When i remove the barrel and coupling clutch it seats fine, it also seats fine with only the barrel fitted. Its when both barrel and clutch are fitted that the bridge rocks and will not sit flat. I have had to source replacement barrel and clutch because the barrel 'pinged' away when i tried removing the mainspring and the clutch was in bits inside the watch.  Anyone have any ideas?

 

 

[Marc]

It may not be any help to you but there is a full rebuild of a 2415 on my blog (link below in my signature).

The only thing that occurs to me is that the click may be resting on top of the ratchet wheel rather than against its rim, which would prevent the bridge from seating properly. The click needs to be held away from the ratchet wheel (against its spring) when fitting the bridge.

[Myron62]

Thanks for your reply Marc. Your blog is impressive. The click is definitely engaged with the ratchet wheel teeth. Very frustrating, i bet its staring me in the face. I will have another look at it.

[Myron62]

I have taken a couple of pictures showing the clutch on top of the barrel; does it look ok or can you spot anything ify?

[Marc]

@Myron62 I have just had a play around with a 2415 that I currently have in pieces to see if I can replicate the problem. Two possible causes come to mind.

1. If the reverser clutch isn't properly seated on the square of the M/S arbor then it will sit high and block the bridge from seating down properly. I don't think this is the case with yours though. Looking at mine, with the reverser clutch properly seated the space between the two reverser wheels is about the same as between the bottom reverser wheel and the barrel, and that looks to be the same as yours. This may be worth a check though.

2. If the barrel lid isn't properly seated on the barrel it may lift the whole assembly slightly out of the main plate. Fitting the bridge without the reverser clutch may still work as the length of the arbor doesn't change. However, if you try it with the clutch in place the increased height of the cluitch wheel above the main plate due to the less than fully seated barrel lid could cause the problem you have. So it might be worth checking that the barrel lid is fully seated.

I don't think that the fact that the barrel and clutch have been replaced should be problematic if they came from another 2415. The barrel arbor is clearly not the issue as everything works without the clutch installed. I does occur to me though looking at your pics that the cluth reverser wheels look slightly thicker than mine. On mine the clutch assembly is 0.90mm thick with no thickening at the hub. If yours is thicker than this or has a raised hub then this would cause a problem.

Glad you like the blog

ps. It's always the ones that are staring you in the face that are the most difficult to spot!!!

Edited June 11, 2019 by Marc
addition of ps