Vostok 2209 Mainspring barrel end shake

[utzelu]

Hi,

As I am on a watchmaking learning journey, as a hobby, and started servicing an old Vostok 2209 movement, I tried assessing the mainspring barrel's end shake and side shake. It seems to me that there is too much movement (especially the end shake) and the pivot hole in the barrel bridge seems a bit oval (there is more movement in a certain direction than in others). I was thinking to attempt at fixing this with a staking tool, but what worries me is the construction of the pivot whole. As seen in the attached photos, the whole is flat on one side of the bridge, but has a "lip" on the other side and my concern is if the lip would be damaged when punching with the staking tool. It's my first attempt at such task, hence my call for advise from the forum members.

Cousins UK has the bridge in stock and that could be an option. Does the replacement bridge usually comes with the jewels or they have to be purchased separately and installed?

Made two short videos for showing the end and lateral shake.

 

 Thank you in advance

Edited November 25, 2022 by utzelu

[utzelu]

It seems I have the following options:

• Leave it as is - I got an average amplitude between 258 to 270 degrees in 6 positions, so it doesn't seem too bad. Also there doesn't seem to be any friction related marks on the bridge, just screwdriver marks probably from the previous "watchmaker"
• Get a NOS bridge - Cousins UK has one in stock and I assume it doesn't have the jewels installed. I guess it's hard getting new jewels for this movement and using the ones from the current plate is a lot of work for me (i.e. never done it)
• Close the pivot hole in the barrel bridge - although I don't have a staking set, I could buy individual domed shaped stakes and use my mini-milling machine as a staking tool. My main concern is that the raised "post" around the pivot hole (sorry, don't know the name) could get damaged in the process
• Bushing - thinking about it, this could be the easiest option for me, as I have a Sherline lathe and milling machine and I could make a brass bushing. On the other hand I could also ruin the bridge as well

[mikepilk]

I would leave it as is. I would say that the side shake is "acceptable", and as you mention, there are no signs of wear from the barrel or ratchet wheel. Certainly not worth spending on a new one, or bushing.

If I did close it with a staking set, I would either : sit it on a stump with a hole in and just close the top, or use two rounded stakes (a method which can cause disagreements  ).  I recently had to close the hole in a barrel lid which has a lip. As the metal is so thin, I used two stakes to close the hole from both sides.

[utzelu]

1 hour ago, mikepilk said:

I would leave it as is. I would say that the side shake is "acceptable", and as you mention, there are no signs of wear from the barrel or ratchet wheel. Certainly not worth spending on a new one, or bushing.

I think this is a wise advice indeed. At this stage I will clean the movement parts once more, reassemble and see what readings will get. Will adjust and regulate and see how it keeps time over a longer period. This watch belonged to my father-in-law and was planning to restore it as much as possible, given my abilities, and give it to my wife to wear it.

[mikepilk]

40 minutes ago, utzelu said:

I think this is a wise advice indeed. At this stage I will clean the movement parts once more, reassemble and see what readings will get. Will adjust and regulate and see how it keeps time over a longer period. This watch belonged to my father-in-law and was planning to restore it as much as possible, given my abilities, and give it to my wife to wear it.

Then when you next service it, in a few years, you can check the play, and if necessary close it with the staking set you will have 

[Paul80]

Hi.

Looking at your videos I don't think the size of the hole is the issue as you have very little side to side movement.  My concern would be the end shake or up and down movement of the barrel, this might indicate the the lip you mention on the bridge is worn significantly or less likely the barrel arbour is worn which I seriously doubt.

The replacement bridge Cousins have should come with the Jewels fitted so depending on cost it might be better to just fit a new one rather than trying to fix the old one.

But then again if it's working fine with no positional error and good amplitude you could leave it as it is for now.

Although a year or two till it does start affecting it's reliability you might fine that one cousins have is now sold.

If the replacement is not too expensive I might be tempted to just replace the bridge now.

[mikepilk]

1 hour ago, Paul80 said:

Hi.

Looking at your videos I don't think the size of the hole is the issue as you have very little side to side movement.  My concern would be the end shake or up and down movement of the barrel, this might indicate the the lip you mention on the bridge is worn significantly or less likely the barrel arbour is worn which I seriously doubt.

The replacement bridge Cousins have should come with the Jewels fitted so depending on cost it might be better to just fit a new one rather than trying to fix the old one.

But then again if it's working fine with no positional error and good amplitude you could leave it as it is for now.

Although a year or two till it does start affecting it's reliability you might fine that one cousins have is now sold.

If the replacement is not too expensive I might be tempted to just replace the bridge now.

The vertical movement does look excessive, but I can't see any wear in the bridge.  It's all working OK. So unless you can see any significant wear - no point in spending money on new parts.  Maybe that's just how these movements are.

[HectorLooi]

Do you actually see the pivots of the barrel arbor moving up and down when you do that? 

Check the endshake of the arbor within the barrel itself. Sometime the barrel cap gets domed when opening up the barrel.

[Paul80]

Good point, it might be wear in the barrel, try moving the barrel up and down whilst applying pressure to the top pivot of the Arbour 

[utzelu]

On 11/29/2022 at 12:18 AM, Paul80 said:

Hi.

Looking at your videos I don't think the size of the hole is the issue as you have very little side to side movement.  My concern would be the end shake or up and down movement of the barrel, this might indicate the the lip you mention on the bridge is worn significantly or less likely the barrel arbour is worn which I seriously doubt.

The replacement bridge Cousins have should come with the Jewels fitted so depending on cost it might be better to just fit a new one rather than trying to fix the old one.

But then again if it's working fine with no positional error and good amplitude you could leave it as it is for now.

Although a year or two till it does start affecting it's reliability you might fine that one cousins have is now sold.

If the replacement is not too expensive I might be tempted to just replace the bridge now.

I checked the barrel arbor and it looks fine - there is no play whatsoever between the arbor and the barrel itself. Since the replacement part is affordable (almost 6 GBP), I ordered it and will compare it with the existing part. I cannot see any significant wear and tear on the bridge so I assume it is the lax tolerances of these movements.

On 11/29/2022 at 2:02 AM, HectorLooi said:

Do you actually see the pivots of the barrel arbor moving up and down when you do that? 

Check the endshake of the arbor within the barrel itself. Sometime the barrel cap gets domed when opening up the barrel.

No up/down or side moving of the arbor within the barrel. The cap is in good condition. Will compare the bridge with the new one I ordered.

[utzelu]

So I received a new mainspring bridge and it has jewels installed. Although with the new part the side shake is ok, the end shake is still too much. I guess the tolerances of these movements are pretty loose. I will use the new part and reassemble and check if the amplitude has improved.