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Vostok calibre 2431 Service Walkthrough


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Introduction

This service walkthrough is not a tutorial on how to service a watch movement. I made it for myself because I think it's fun and because it will make it easier the next time I service a Vostok 2431. I also think it feels nice to be able to share this walkthrough considering all the valuable information that many very talented members on WRT freely share. Many, many thanks!

There is a lot to learn when servicing a watch movement that is not covered in this walkthrough. Therefore, I recommend, for example, watchfix.com, learnwatchmaking.com, or timezonewatchschool.com. I feel like I got the most bang for my buck at watchfix.com (I'm not sponsored in any way) but I've also had a lot of fun and benefited from the other online schools.

Links to photos on my OneDrive

Vostok calibre 2431 disassembly walkthrough. Please sort the images by name in ascending order.

Vostok calibre 2431 assembly walkthrough. Please sort the images by name in ascending order.

Curiosities

IMG_9232.JPG.6d394e52c05838efe3fbc12ecadee9bb.JPG

I think it was in 2014 or possibly 2015 that I bought my Sturmanskie Open Space. I had just discovered that there were watches where the hour hand only rotates one revolution per day and at that time I knew absolutely nothing about watch movements, service and repair. The idea that the hour hand of a watch only rotates one revolution per day seemed not only completely logical but also different and fascinating. The earth rotates one revolution around its axis per day, so it should be obvious that the hour hands of our watches do so too. The fact that the letters on the watch were also Cyrillic did not make the whole thing any less exciting. I just couldn’t resist it and I’m happy I didn’t!

Vostok claims that their movements only need a service every 10 years, and I think that's true because the tolerances are pretty rough and therefore large amounts of dirt are needed to stop a Russian movement or even cause it to run badly. It has been said that the amount of dirt required to stop a Vostok movement is enough to stop a hundred Patek Philippe movements 😉

However, the price for this endurance is a movement that doesn't come close to the precision offered by high-quality Swiss and Japanese movements, but it's still quite easy to get these Russian movements to run accurately as long as they're worn and used consistently.

About the movement

Russian watch brands such as Vostok, Raketa, and Poljot, to name a few, are known for using their in-house movements, but not this Sturmanskie which is instead powered by a Vostok calibre 2431, which is a 24-hour movement. However, it is not a true 24-hour movement. That is, the movement is not originally designed as a 24-hour movement. Instead, Vostok has modified the movement in its calibre 2416B so that the hour hand only rotates one revolution per day. Calibre 2431 is otherwise identical to Vostok automatic calibres 2416B and 2415.

The motion work(/dial train) in Vostok 2431

The way that Vostok modified the movement so that the hour hand only rotates one revolution per day is by modifying a) the minute wheel, b) the bearing for the minute wheel in the main plate, and c), adding an intermediate date indicator wheel.

IMG_8658.JPG.a2719633eb217559d78a393bfb9bda11.JPG
The minute wheel has been modified so that it has two pinions that lie on top of each other. The lower pinion drives what I call the first intermediate date indicator wheel while the upper pinion drives the hour wheel and has been adjusted so that the hour wheel only rotates one revolution per day. The number of teeth on the hour wheel itself may have also been adapted, but this is not something that I have investigated.

IMG_8655.JPG.6dd14ec8b99499740d755f2309762fbc.JPG
Normally the minute wheel is mounted on a regular metal post on the main plate, but in this case, Vostok has replaced the post with a beefy, jewelled bearing. I assume that this has been necessary to get the minute wheel, with its two pinions on top of each other, to rotate sufficiently smoothly and stably.

IMG_8695.JPG.ab429459d6ee4120edf5483f53b2cedc.JPG
The added first intermediate date indicator wheel drives the second intermediate date indicator wheel which is part of Vostok's regular (non-modified) calendar complication.

IMG_8696.JPG.b9a2e07e135408afcef1998926152f33.JPG
And this is what it looks like with the hour wheel mounted.

Cleaning

I have found that it is all too easy to underestimate the importance of cleanliness when servicing a movement, perhaps because the parts are microscopic and therefore it takes time to get used to thinking microscopically, even though I have been doing this now for five years.

Cleaning of pinions and pivots

A type of watch movement part that is particularly important but also difficult to get completely clean is pinions, but @nickelsilver advised me quite recently that in its pre-cleaning you can dip and rub the pinions in pith wood that you have impregnated with an effective degreasing agent, for example, Horosolv. I've done it several times now and it works amazingly well.

Speaking of pinions, independent American watchmaker Josh Shapiro mentioned in a podcast that he considered pinions to be the most difficult part of a watch movement to make perfectly. Whether it's true or not I don't know but I think it's likely.

To get the pivots clinically clean, I have also started using EVEFLEX, but you have to be careful because the material has an abrasive effect. It is important to choose the right polisher and to be careful. I have summarized my experiences with EVEFLEX in this post and I mention it because EVEFLEX is easy and quick to work with and gives me very good results.

End-shake

If there's one thing I've learned this time around, it is that a Russian movement cannot be converted to a Swiss movement because the tolerances in Russian movements are generally much coarser.

Experimentally, I adjusted the end-shake to 2/100mm on everything from the pallet fork to the centre wheel, with the result that the amplitude and rate became extremely erratic. I created a thread about this: "Can end-shake and or side-shake ever be too small?" As you will see if you follow the thread, once again @nickelsilver@Shane, and @JohnR725came to my rescue. Many thanks!

My recommendation is to let the end-shake be slightly wider on Russian movements. After I increased the end-shake to approx. 4/100 mm, the amplitude and rate returned to typical, i.e., still somewhat irregular but perfectly normal for a Russian movement.

Side-shake

In this video, Kalle Slaap from Chronoglide shows an amazingly simple and effective way to determine if the side shake is correct. Since there was a crack in the third wheel jewel in the train wheel bridge, I replaced it, and when I then used Kalle Slaap's method, I could clearly see the 3rd wheel pivot jumping back and forth in the jewel hole. So, I replaced the jewel with a hole that was 1/100mm smaller and the visual difference, just changing it by 1/100 mm, was nothing less than dramatic. I am incredibly happy that I got to learn this simple and exceptionally clear method. Many thanks to Kalle Slaap at Chronoglide!

Vostok reverser wheels

If you Google “Vostok reverser wheels”, there is a lot of whining going on. I don't think there are any major problems with Vostok's reverser wheels, but they are unfortunately easy to damage during service or modification of the movement, and I think that is the real reason for the whining. Next to Seiko watches, Vostok watches are immensely popular to modify in terms of dials and hands, and in addition, many people want to fix the seconds hand that sometimes stutters on these movements. The latter is done by bending the second-hand pinion spring illustrated in this thread.

To make these modifications, the oscillating weight/rotor must be removed and when it is to be screwed back on, it is easy for the rotor pinion to end up on top of the teeth of the reverser wheels. If you tighten the rotor screw in that position, even just a little, the reverser wheels will inevitably be damaged. The result is that the automatic winding stops working or only works intermittently.

IMG_8720.JPG.90005fb8be311ab73d933e77b258c5e4.JPG

An easy way to check if the reverser wheels are working as they should is to manually rotate the oscillating weight alternately about 20 degrees in both directions with a piece of peg wood while looking at the 1st reduction wheel which is large and easy to see. If the 1st reduction wheel continuously rotates in the same direction (counterclockwise, if I remember correctly), no matter which way you rotate the oscillating weight, you can be sure that the reverser wheels are working as they should. If, on the other hand, the 1st reduction wheel rotates alternately in both directions when you rotate the oscillating weight alternately, then you can be sure that the reverser wheels are damaged and need to be replaced.

Servicing the automatic mainspring

I find it difficult to service the mainspring on automatic movements. It is, in my opinion, a construction that leaves room for improvement and that is why I generally prefer manually wound movements.

If the mainspring in an automatic movement slips too soon, it reduces the amplitude and the power reserve, and if the mainspring slips too late, there is the risk of re-banking and that the movement runs much too fast when you are physically active, especially when you take a brisk walk swinging your arms, and the oscillating weight rotates constantly. The effect is like continuously turning the crown of a manual movement with high pressure when the mainspring is already fully wound. Not good!

What I learned this time anyway, long story short is that you can be quite generous with braking grease on the rim on the inside of the mainspring barrel. Even if some of the braking grease ends up where it really shouldn't be, I don't think it will destroy or affect anything negatively. Also, and again from Kalle Slaap at Chronoglide, I learned that you should press at the end of the spring at the bridle when it is mounted in a spacer, and you are about to push it into the mainspring barrel. In this way, the rest of the spring automatically follows down into the mainspring barrel. You can see it in this clip. Very smooth, especially in combination with my highly rated Master Craft mainspring winder which I wrote about in this post.

Lubrication of cap jewels

For a long time, I have had trouble getting the oil to stay in the centre of the cap jewels and not flow out after I oiled them and installed them, despite treating them with epilame (Fixodrop). I think it's because (and now I'm going by gut feeling) that I previously always installed the shock assembly in the main plate before installing the balance and that I didn't treat the jewel housing (chaton) with epilame. After several failures in servicing this movement, I decided to treat both the cap jewels and jewel housings with epilame and mount the shock assembly after having replaced the balance. It did the trick and also made fitting the three-legged anti-shock spring much easier. My theory is that the balance staff pivots stabilize the oil in the centre of the cap jewels when the jewel housing (chaton) is dropped into place, and better hold the jewel housing in place, which will otherwise slide around while installing the three-legged anti-shock springs.

Have I just written the longest post in the history of WRT🤔 Anyway, hope you enjoyed it!

Edited by VWatchie
Tried to make the text a little easier to understand
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Thanks for your kind words @gbyleveldt🙂 Absolutely, go ahead, these Vostok movements are so much fun, and when you lose or damage a part, just pick up a bag of used Vostok movements on eBay for next to nothing compared to Swiss and Japanese movements.

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5 hours ago, VWatchie said:

Introduction

This service walkthrough is not a tutorial on how to service a watch movement. I made it for myself because I think it's fun and because it will make it easier the next time I service a Vostok 2431. I also think it feels nice to be able to share this walkthrough considering all the valuable information that many very talented members on WRT freely share. Many, many thanks!

There is a lot to learn when servicing a watch movement that is not covered in this walkthrough. Therefore, I recommend, for example, watchfix.com, learnwatchmaking.com, or timezonewatchschool.com. I feel like I got the most bang for my buck at watchfix.com (I'm not sponsored in any way) but I've also had a lot of fun and benefited from the other online schools.

Links to photos on my OneDrive

Vostok calibre 2431 disassembly walkthrough. Please sort the images by name in ascending order.

Vostok calibre 2431 assembly walkthrough. Please sort the images by name in ascending order.

Curiosities

IMG_9232.JPG.6d394e52c05838efe3fbc12ecadee9bb.JPG

I think it was in 2014 or possibly 2015 that I bought my Sturmanskie Open Space. I had just discovered that there were watches where the hour hand only rotates one revolution per day and at that time I knew absolutely nothing about watch movements, service and repair. The idea that the hour hand of a watch only rotates one revolution per day seemed not only completely logical but also different and fascinating. The earth rotates one revolution around its axis per day, so it should be obvious that the hour hands of our watches do so too. The fact that the letters on the watch were also Cyrillic did not make the whole thing any less exciting. I just couldn’t resist it and I’m happy I didn’t!

Vostok claims that their movements only need service every 10 years, and I think that's true because the tolerances are pretty rough and therefore large amounts of dirt are needed to stop a Russian movement or even cause it to run badly. It has been said that the amount of dirt required to stop a Vostok movement is enough to stop a hundred Patek Philippe movements 😉

However, the price for this endurance is a movement that doesn't come close to the precision offered by high-quality Swiss and Japanese movements, but it's still quite easy to get these Russian movements to run accurately as long as they're worn and used consistently.

About the movement

Russian watch brands such as Vostok, Raketa, and Poljot, to name a few, are known for using their in-house movements, but not this Sturmanskie which is instead powered by a Vostok calibre 2431, which is a 24-hour movement. However, it is not a true 24-hour movement. That is, the movement is not originally designed as a 24-hour movement. Instead, Vostok has modified the movement in its calibre 2416B so that the hour hand only rotates one revolution per day. Calibre 2431 is otherwise identical to Vostok automatic calibres 2416B and 2415.

The motion work(/dial train) in Vostok 2431

The way that Vostok modified the movement so that the hour hand only rotates one revolution per day is by modifying a) the minute wheel, b) the bearing for the minute wheel in the main plate, and c), adding an intermediate date indicator wheel.

IMG_8658.JPG.a2719633eb217559d78a393bfb9bda11.JPG
The minute wheel has been modified so that it has two pinions that lie on top of each other. The lower pinion drives what I call the first intermediate date indicator wheel while the upper pinion drives the hour wheel and has been adjusted so that the hour wheel only rotates one revolution per day. The number of teeth on the hour wheel itself may have also been adapted, but this is not something that I have investigated.

IMG_8655.JPG.6dd14ec8b99499740d755f2309762fbc.JPG
Normally the minute wheel is mounted on a regular post on the main plate, but in this case, Vostok has replaced the post with a beefy, jewelled bearing. I assume that this has been necessary to get the minute wheel, with its two pinions on top of each other, to rotate sufficiently smoothly and stably.

IMG_8695.JPG.ab429459d6ee4120edf5483f53b2cedc.JPG
The added first intermediate date indicator wheel drives the second intermediate date indicator wheel which is part of Vostok's regular (non-modified) calendar complication.

IMG_8696.JPG.b9a2e07e135408afcef1998926152f33.JPG
And this is what it looks like with the hour wheel mounted.

Cleaning

I have found that it is all too easy to underestimate the importance of cleanliness when servicing a movement, perhaps because the parts are microscopic and therefore it takes time to get used to thinking microscopically, even though I have been doing this now for five years.

Cleaning of pinions and pivots

A type of watch movement part that is particularly important but also difficult to get completely clean is pinions, but @nickelsilver advised me quite recently that in its pre-cleaning you can dip and rub the pinions in pith wood that you have impregnated with an effective degreasing agent, for example, Horosolv. I've done it several times now and it works amazingly well.

Speaking of pinions, independent American watchmaker Josh Shapiro mentioned in a podcast that he considered pinions to be the most difficult part of a watch movement to make perfectly. Whether it's true or not I don't know but I think it's likely.

To get the pivots clinically clean, I have also started using EVEFLEX, but you have to be careful because the material has an abrasive effect. It is important to choose the right polisher and to be careful. I have summarized my experiences with EVEFLEX in this post and I mention it because EVEFLEX is easy and quick to work with and gives me very good results.

End-shake

If there's one thing I've learned this time around, it is that a Russian movement cannot be converted to a Swiss movement because the tolerances in Russian movements are generally much coarser.

Experimentally, I adjusted the end-shake to 2/100mm on everything from the pallet fork to the centre wheel, with the result that the amplitude and rate became extremely erratic. I created a thread about this: "Can end-shake and or side-shake ever be too small?" As you will see if you follow the thread, once again @nickelsilver@Shane, and @JohnR725came to my rescue. Many thanks!

My recommendation is to let the end-shake be slightly wider on Russian movements. After I increased the end-shake to approx. 4/100 mm, the amplitude and rate returned to typical, i.e., still somewhat irregular but perfectly normal for a Russian movement.

Side-shake

In this video, Kalle Slaap from Chronoglide shows an amazingly simple and effective way to determine if the side shake is correct. Since there was a crack in the third wheel jewel in the train wheel bridge, I replaced it, and when I then used Kalle Slaap's method, I could clearly see the 3rd wheel pivot jumping back and forth in the jewel hole. So, I replaced the jewel with a hole that was 1/100mm smaller and the visual difference just changing it to 1/100 mm was nothing less than dramatic. I am incredibly happy that I got to learn this simple and exceptionally clear method. Many thanks to Kalle Slaap at Chronoglide!

Vostok reverser wheels

If you Google “Vostok reverser wheels”, there is a lot of whining going on. I don't think there are any major problems with Vostok's reverser wheels, but they are unfortunately easy to damage during service or modification of the movement, and I think that is the real reason for the whining. Next to Seiko watches, Vostok watches are immensely popular to modify in terms of dials and hands, and in addition, many people want to fix the seconds hand that sometimes stutters on these movements. The latter is done by bending the second-hand pinion spring illustrated in this thread.

To make these modifications, the oscillating weight/rotor must be removed and when it is to be screwed back on, it is easy for the rotor pinion to end up on top of the teeth of the reverser wheels. If you tighten the rotor screw in that position, even just a little, the reverser wheels will inevitably be damaged. The result is that the automatic winding stops working or only works intermittently.

IMG_8720.JPG.90005fb8be311ab73d933e77b258c5e4.JPG

An easy way to check if the reverser wheels are working as they should is to manually rotate the oscillating weight alternately about 20 degrees in both directions with a piece of peg wood while looking at the 1st reduction wheel which is large and easy to see. If the 1st reduction wheel continuously rotates in the same direction (counterclockwise, if I remember correctly), no matter which way you rotate the oscillating weight, you can be sure that the reverser wheels are working as they should. If, on the other hand, the 1st reduction wheel rotates alternately in both directions when you rotate the oscillating weight alternately, then you can be sure that the reverser wheels are damaged and need to be replaced.

Servicing the automatic mainspring

I find it difficult to service the mainspring on automatic movements. It is, in my opinion, a construction that leaves room for improvement and that is why I generally prefer manually wound movements.

If the mainspring in an automatic movement slips too soon, it affects the amplitude and the power reserve, and if the mainspring slips too late, there is the risk of re-banking and that the movement runs much too fast when you are physically active, especially when you take a brisk walk swinging your arms, and the oscillating weight rotates constantly. The effect is like continuously turning the crown of a manual movement with high pressure when the mainspring is already fully wound. Not good!

What I learned this time anyway, long story short is that you can be quite generous with braking grease on the rim on the inside of the mainspring barrel. Even if some of the braking grease ends up where it really shouldn't be, I don't think it will destroy or affect anything negatively. Also, and again from Kalle Slaap at Chronoglide, I learned that you should press at the end of the spring at the bridle when it is mounted in a spacer, and you are about to push it into the mainspring barrel. In this way, the rest of the spring automatically follows down into the mainspring barrel. Very smooth, especially in combination with my highly rated Master Craft mainspring winder which I wrote about in this post.

Lubrication of cap jewels

For a long time, I have had trouble getting the oil to stay in the centre of the cap jewels and not flow out after I oiled them and installed them, despite treating them with epilame (Fixodrop). I think it's because (and now I'm going by gut feeling) that I previously always installed the shock assembly in the main plate before installing the balance and that I didn't treat the jewel housing (chaton) with epilame. After several failures in servicing this movement, I decided to treat both the cap jewels and jewel housings with epilame and mount the balance before the shock assembly. It did the trick and also made fitting the three-legged anti-shock spring much easier. My theory is that the balance staff pivots stabilize the oil in the centre of the cap jewels and better hold the jewel housing in place, which will otherwise slide around while installing the three-legged anti-shock springs.

Have I just written the longest post in the history of WRT🤔 Anyway, hope you enjoyed it!

Appreciate this post Watchie, your information is always spot on my friend and worthy of commiting to memory. Particularly interesting regarding lubrication with the balance staff in place. I am in historic York in the UK this week, lots of antique shops. Spotted some early big post war Russian watches you may be interested in possibly having a Rolex connection . I will get some photos tomorrow. Look forward to your next post, where have you been ? 🙁

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17 hours ago, VWatchie said:

Introduction

This service walkthrough is not a tutorial on how to service a watch movement. I made it for myself because I think it's fun and because it will make it easier the next time I service a Vostok 2431. I also think it feels nice to be able to share this walkthrough considering all the valuable information that many very talented members on WRT freely share. Many, many thanks!

There is a lot to learn when servicing a watch movement that is not covered in this walkthrough. Therefore, I recommend, for example, watchfix.com, learnwatchmaking.com, or timezonewatchschool.com. I feel like I got the most bang for my buck at watchfix.com (I'm not sponsored in any way) but I've also had a lot of fun and benefited from the other online schools.

Links to photos on my OneDrive

Vostok calibre 2431 disassembly walkthrough. Please sort the images by name in ascending order.

Vostok calibre 2431 assembly walkthrough. Please sort the images by name in ascending order.

Curiosities

IMG_9232.JPG.6d394e52c05838efe3fbc12ecadee9bb.JPG

I think it was in 2014 or possibly 2015 that I bought my Sturmanskie Open Space. I had just discovered that there were watches where the hour hand only rotates one revolution per day and at that time I knew absolutely nothing about watch movements, service and repair. The idea that the hour hand of a watch only rotates one revolution per day seemed not only completely logical but also different and fascinating. The earth rotates one revolution around its axis per day, so it should be obvious that the hour hands of our watches do so too. The fact that the letters on the watch were also Cyrillic did not make the whole thing any less exciting. I just couldn’t resist it and I’m happy I didn’t!

Vostok claims that their movements only need a service every 10 years, and I think that's true because the tolerances are pretty rough and therefore large amounts of dirt are needed to stop a Russian movement or even cause it to run badly. It has been said that the amount of dirt required to stop a Vostok movement is enough to stop a hundred Patek Philippe movements 😉

However, the price for this endurance is a movement that doesn't come close to the precision offered by high-quality Swiss and Japanese movements, but it's still quite easy to get these Russian movements to run accurately as long as they're worn and used consistently.

About the movement

Russian watch brands such as Vostok, Raketa, and Poljot, to name a few, are known for using their in-house movements, but not this Sturmanskie which is instead powered by a Vostok calibre 2431, which is a 24-hour movement. However, it is not a true 24-hour movement. That is, the movement is not originally designed as a 24-hour movement. Instead, Vostok has modified the movement in its calibre 2416B so that the hour hand only rotates one revolution per day. Calibre 2431 is otherwise identical to Vostok automatic calibres 2416B and 2415.

The motion work(/dial train) in Vostok 2431

The way that Vostok modified the movement so that the hour hand only rotates one revolution per day is by modifying a) the minute wheel, b) the bearing for the minute wheel in the main plate, and c), adding an intermediate date indicator wheel.

IMG_8658.JPG.a2719633eb217559d78a393bfb9bda11.JPG
The minute wheel has been modified so that it has two pinions that lie on top of each other. The lower pinion drives what I call the first intermediate date indicator wheel while the upper pinion drives the hour wheel and has been adjusted so that the hour wheel only rotates one revolution per day. The number of teeth on the hour wheel itself may have also been adapted, but this is not something that I have investigated.

IMG_8655.JPG.6dd14ec8b99499740d755f2309762fbc.JPG
Normally the minute wheel is mounted on a regular metal post on the main plate, but in this case, Vostok has replaced the post with a beefy, jewelled bearing. I assume that this has been necessary to get the minute wheel, with its two pinions on top of each other, to rotate sufficiently smoothly and stably.

IMG_8695.JPG.ab429459d6ee4120edf5483f53b2cedc.JPG
The added first intermediate date indicator wheel drives the second intermediate date indicator wheel which is part of Vostok's regular (non-modified) calendar complication.

IMG_8696.JPG.b9a2e07e135408afcef1998926152f33.JPG
And this is what it looks like with the hour wheel mounted.

Cleaning

I have found that it is all too easy to underestimate the importance of cleanliness when servicing a movement, perhaps because the parts are microscopic and therefore it takes time to get used to thinking microscopically, even though I have been doing this now for five years.

Cleaning of pinions and pivots

A type of watch movement part that is particularly important but also difficult to get completely clean is pinions, but @nickelsilver advised me quite recently that in its pre-cleaning you can dip and rub the pinions in pith wood that you have impregnated with an effective degreasing agent, for example, Horosolv. I've done it several times now and it works amazingly well.

Speaking of pinions, independent American watchmaker Josh Shapiro mentioned in a podcast that he considered pinions to be the most difficult part of a watch movement to make perfectly. Whether it's true or not I don't know but I think it's likely.

To get the pivots clinically clean, I have also started using EVEFLEX, but you have to be careful because the material has an abrasive effect. It is important to choose the right polisher and to be careful. I have summarized my experiences with EVEFLEX in this post and I mention it because EVEFLEX is easy and quick to work with and gives me very good results.

End-shake

If there's one thing I've learned this time around, it is that a Russian movement cannot be converted to a Swiss movement because the tolerances in Russian movements are generally much coarser.

Experimentally, I adjusted the end-shake to 2/100mm on everything from the pallet fork to the centre wheel, with the result that the amplitude and rate became extremely erratic. I created a thread about this: "Can end-shake and or side-shake ever be too small?" As you will see if you follow the thread, once again @nickelsilver@Shane, and @JohnR725came to my rescue. Many thanks!

My recommendation is to let the end-shake be slightly wider on Russian movements. After I increased the end-shake to approx. 4/100 mm, the amplitude and rate returned to typical, i.e., still somewhat irregular but perfectly normal for a Russian movement.

Side-shake

In this video, Kalle Slaap from Chronoglide shows an amazingly simple and effective way to determine if the side shake is correct. Since there was a crack in the third wheel jewel in the train wheel bridge, I replaced it, and when I then used Kalle Slaap's method, I could clearly see the 3rd wheel pivot jumping back and forth in the jewel hole. So, I replaced the jewel with a hole that was 1/100mm smaller and the visual difference, just changing it by 1/100 mm, was nothing less than dramatic. I am incredibly happy that I got to learn this simple and exceptionally clear method. Many thanks to Kalle Slaap at Chronoglide!

Vostok reverser wheels

If you Google “Vostok reverser wheels”, there is a lot of whining going on. I don't think there are any major problems with Vostok's reverser wheels, but they are unfortunately easy to damage during service or modification of the movement, and I think that is the real reason for the whining. Next to Seiko watches, Vostok watches are immensely popular to modify in terms of dials and hands, and in addition, many people want to fix the seconds hand that sometimes stutters on these movements. The latter is done by bending the second-hand pinion spring illustrated in this thread.

To make these modifications, the oscillating weight/rotor must be removed and when it is to be screwed back on, it is easy for the rotor pinion to end up on top of the teeth of the reverser wheels. If you tighten the rotor screw in that position, even just a little, the reverser wheels will inevitably be damaged. The result is that the automatic winding stops working or only works intermittently.

IMG_8720.JPG.90005fb8be311ab73d933e77b258c5e4.JPG

An easy way to check if the reverser wheels are working as they should is to manually rotate the oscillating weight alternately about 20 degrees in both directions with a piece of peg wood while looking at the 1st reduction wheel which is large and easy to see. If the 1st reduction wheel continuously rotates in the same direction (counterclockwise, if I remember correctly), no matter which way you rotate the oscillating weight, you can be sure that the reverser wheels are working as they should. If, on the other hand, the 1st reduction wheel rotates alternately in both directions when you rotate the oscillating weight alternately, then you can be sure that the reverser wheels are damaged and need to be replaced.

Servicing the automatic mainspring

I find it difficult to service the mainspring on automatic movements. It is, in my opinion, a construction that leaves room for improvement and that is why I generally prefer manually wound movements.

If the mainspring in an automatic movement slips too soon, it reduces the amplitude and the power reserve, and if the mainspring slips too late, there is the risk of re-banking and that the movement runs much too fast when you are physically active, especially when you take a brisk walk swinging your arms, and the oscillating weight rotates constantly. The effect is like continuously turning the crown of a manual movement with high pressure when the mainspring is already fully wound. Not good!

What I learned this time anyway, long story short is that you can be quite generous with braking grease on the rim on the inside of the mainspring barrel. Even if some of the braking grease ends up where it really shouldn't be, I don't think it will destroy or affect anything negatively. Also, and again from Kalle Slaap at Chronoglide, I learned that you should press at the end of the spring at the bridle when it is mounted in a spacer, and you are about to push it into the mainspring barrel. In this way, the rest of the spring automatically follows down into the mainspring barrel. You can see it in this clip. Very smooth, especially in combination with my highly rated Master Craft mainspring winder which I wrote about in this post.

Lubrication of cap jewels

For a long time, I have had trouble getting the oil to stay in the centre of the cap jewels and not flow out after I oiled them and installed them, despite treating them with epilame (Fixodrop). I think it's because (and now I'm going by gut feeling) that I previously always installed the shock assembly in the main plate before installing the balance and that I didn't treat the jewel housing (chaton) with epilame. After several failures in servicing this movement, I decided to treat both the cap jewels and jewel housings with epilame and mount the shock assembly after having replaced the balance. It did the trick and also made fitting the three-legged anti-shock spring much easier. My theory is that the balance staff pivots stabilize the oil in the centre of the cap jewels when the jewel housing (chaton) is dropped into place, and better hold the jewel housing in place, which will otherwise slide around while installing the three-legged anti-shock springs.

Have I just written the longest post in the history of WRT🤔 Anyway, hope you enjoyed it!

Here you go Watchie, a little wrist eye candy for you. A couple of them reminiscent of IWC pilots. Not a Russian brand i have heard of, i hope you can read the history card.

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11 hours ago, Neverenoughwatches said:

Look forward to your next post, where have you been ? 🙁

Thanks for your kind words @Neverenoughwatches😃

Well, I try to stay away from the Internet and spend more time in the real world. After all, the best thing you can do to become good at servicing and repairing watches is to service and repair watches, and time is limited.

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3 hours ago, VWatchie said:

Thanks for your kind words @Neverenoughwatches😃

Well, I try to stay away from the Internet and spend more time in the real world. After all, the best thing you can do to become good at servicing and repairing watches is to service and repair watches, and time is limited.

👍 As long as you keep stopping by matey.

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22 hours ago, VWatchie said:

Introduction

This service walkthrough is not a tutorial on how to service a watch movement. I made it for myself because I think it's fun and because it will make it easier the next time I service a Vostok 2431. I also think it feels nice to be able to share this walkthrough considering all the valuable information that many very talented members on WRT freely share. Many, many thanks!

There is a lot to learn when servicing a watch movement that is not covered in this walkthrough. Therefore, I recommend, for example, watchfix.com, learnwatchmaking.com, or timezonewatchschool.com. I feel like I got the most bang for my buck at watchfix.com (I'm not sponsored in any way) but I've also had a lot of fun and benefited from the other online schools.

Links to photos on my OneDrive

Vostok calibre 2431 disassembly walkthrough. Please sort the images by name in ascending order.

Vostok calibre 2431 assembly walkthrough. Please sort the images by name in ascending order.

Curiosities

IMG_9232.JPG.6d394e52c05838efe3fbc12ecadee9bb.JPG

I think it was in 2014 or possibly 2015 that I bought my Sturmanskie Open Space. I had just discovered that there were watches where the hour hand only rotates one revolution per day and at that time I knew absolutely nothing about watch movements, service and repair. The idea that the hour hand of a watch only rotates one revolution per day seemed not only completely logical but also different and fascinating. The earth rotates one revolution around its axis per day, so it should be obvious that the hour hands of our watches do so too. The fact that the letters on the watch were also Cyrillic did not make the whole thing any less exciting. I just couldn’t resist it and I’m happy I didn’t!

Vostok claims that their movements only need a service every 10 years, and I think that's true because the tolerances are pretty rough and therefore large amounts of dirt are needed to stop a Russian movement or even cause it to run badly. It has been said that the amount of dirt required to stop a Vostok movement is enough to stop a hundred Patek Philippe movements 😉

However, the price for this endurance is a movement that doesn't come close to the precision offered by high-quality Swiss and Japanese movements, but it's still quite easy to get these Russian movements to run accurately as long as they're worn and used consistently.

About the movement

Russian watch brands such as Vostok, Raketa, and Poljot, to name a few, are known for using their in-house movements, but not this Sturmanskie which is instead powered by a Vostok calibre 2431, which is a 24-hour movement. However, it is not a true 24-hour movement. That is, the movement is not originally designed as a 24-hour movement. Instead, Vostok has modified the movement in its calibre 2416B so that the hour hand only rotates one revolution per day. Calibre 2431 is otherwise identical to Vostok automatic calibres 2416B and 2415.

The motion work(/dial train) in Vostok 2431

The way that Vostok modified the movement so that the hour hand only rotates one revolution per day is by modifying a) the minute wheel, b) the bearing for the minute wheel in the main plate, and c), adding an intermediate date indicator wheel.

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The minute wheel has been modified so that it has two pinions that lie on top of each other. The lower pinion drives what I call the first intermediate date indicator wheel while the upper pinion drives the hour wheel and has been adjusted so that the hour wheel only rotates one revolution per day. The number of teeth on the hour wheel itself may have also been adapted, but this is not something that I have investigated.

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Normally the minute wheel is mounted on a regular metal post on the main plate, but in this case, Vostok has replaced the post with a beefy, jewelled bearing. I assume that this has been necessary to get the minute wheel, with its two pinions on top of each other, to rotate sufficiently smoothly and stably.

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The added first intermediate date indicator wheel drives the second intermediate date indicator wheel which is part of Vostok's regular (non-modified) calendar complication.

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And this is what it looks like with the hour wheel mounted.

Cleaning

I have found that it is all too easy to underestimate the importance of cleanliness when servicing a movement, perhaps because the parts are microscopic and therefore it takes time to get used to thinking microscopically, even though I have been doing this now for five years.

Cleaning of pinions and pivots

A type of watch movement part that is particularly important but also difficult to get completely clean is pinions, but @nickelsilver advised me quite recently that in its pre-cleaning you can dip and rub the pinions in pith wood that you have impregnated with an effective degreasing agent, for example, Horosolv. I've done it several times now and it works amazingly well.

Speaking of pinions, independent American watchmaker Josh Shapiro mentioned in a podcast that he considered pinions to be the most difficult part of a watch movement to make perfectly. Whether it's true or not I don't know but I think it's likely.

To get the pivots clinically clean, I have also started using EVEFLEX, but you have to be careful because the material has an abrasive effect. It is important to choose the right polisher and to be careful. I have summarized my experiences with EVEFLEX in this post and I mention it because EVEFLEX is easy and quick to work with and gives me very good results.

End-shake

If there's one thing I've learned this time around, it is that a Russian movement cannot be converted to a Swiss movement because the tolerances in Russian movements are generally much coarser.

Experimentally, I adjusted the end-shake to 2/100mm on everything from the pallet fork to the centre wheel, with the result that the amplitude and rate became extremely erratic. I created a thread about this: "Can end-shake and or side-shake ever be too small?" As you will see if you follow the thread, once again @nickelsilver@Shane, and @JohnR725came to my rescue. Many thanks!

My recommendation is to let the end-shake be slightly wider on Russian movements. After I increased the end-shake to approx. 4/100 mm, the amplitude and rate returned to typical, i.e., still somewhat irregular but perfectly normal for a Russian movement.

Side-shake

In this video, Kalle Slaap from Chronoglide shows an amazingly simple and effective way to determine if the side shake is correct. Since there was a crack in the third wheel jewel in the train wheel bridge, I replaced it, and when I then used Kalle Slaap's method, I could clearly see the 3rd wheel pivot jumping back and forth in the jewel hole. So, I replaced the jewel with a hole that was 1/100mm smaller and the visual difference, just changing it by 1/100 mm, was nothing less than dramatic. I am incredibly happy that I got to learn this simple and exceptionally clear method. Many thanks to Kalle Slaap at Chronoglide!

Vostok reverser wheels

If you Google “Vostok reverser wheels”, there is a lot of whining going on. I don't think there are any major problems with Vostok's reverser wheels, but they are unfortunately easy to damage during service or modification of the movement, and I think that is the real reason for the whining. Next to Seiko watches, Vostok watches are immensely popular to modify in terms of dials and hands, and in addition, many people want to fix the seconds hand that sometimes stutters on these movements. The latter is done by bending the second-hand pinion spring illustrated in this thread.

To make these modifications, the oscillating weight/rotor must be removed and when it is to be screwed back on, it is easy for the rotor pinion to end up on top of the teeth of the reverser wheels. If you tighten the rotor screw in that position, even just a little, the reverser wheels will inevitably be damaged. The result is that the automatic winding stops working or only works intermittently.

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An easy way to check if the reverser wheels are working as they should is to manually rotate the oscillating weight alternately about 20 degrees in both directions with a piece of peg wood while looking at the 1st reduction wheel which is large and easy to see. If the 1st reduction wheel continuously rotates in the same direction (counterclockwise, if I remember correctly), no matter which way you rotate the oscillating weight, you can be sure that the reverser wheels are working as they should. If, on the other hand, the 1st reduction wheel rotates alternately in both directions when you rotate the oscillating weight alternately, then you can be sure that the reverser wheels are damaged and need to be replaced.

Servicing the automatic mainspring

I find it difficult to service the mainspring on automatic movements. It is, in my opinion, a construction that leaves room for improvement and that is why I generally prefer manually wound movements.

If the mainspring in an automatic movement slips too soon, it reduces the amplitude and the power reserve, and if the mainspring slips too late, there is the risk of re-banking and that the movement runs much too fast when you are physically active, especially when you take a brisk walk swinging your arms, and the oscillating weight rotates constantly. The effect is like continuously turning the crown of a manual movement with high pressure when the mainspring is already fully wound. Not good!

What I learned this time anyway, long story short is that you can be quite generous with braking grease on the rim on the inside of the mainspring barrel. Even if some of the braking grease ends up where it really shouldn't be, I don't think it will destroy or affect anything negatively. Also, and again from Kalle Slaap at Chronoglide, I learned that you should press at the end of the spring at the bridle when it is mounted in a spacer, and you are about to push it into the mainspring barrel. In this way, the rest of the spring automatically follows down into the mainspring barrel. You can see it in this clip. Very smooth, especially in combination with my highly rated Master Craft mainspring winder which I wrote about in this post.

Lubrication of cap jewels

For a long time, I have had trouble getting the oil to stay in the centre of the cap jewels and not flow out after I oiled them and installed them, despite treating them with epilame (Fixodrop). I think it's because (and now I'm going by gut feeling) that I previously always installed the shock assembly in the main plate before installing the balance and that I didn't treat the jewel housing (chaton) with epilame. After several failures in servicing this movement, I decided to treat both the cap jewels and jewel housings with epilame and mount the shock assembly after having replaced the balance. It did the trick and also made fitting the three-legged anti-shock spring much easier. My theory is that the balance staff pivots stabilize the oil in the centre of the cap jewels when the jewel housing (chaton) is dropped into place, and better hold the jewel housing in place, which will otherwise slide around while installing the three-legged anti-shock springs.

Have I just written the longest post in the history of WRT🤔 Anyway, hope you enjoyed it!

Great detailed post indeed. Many will enjoy thanks

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@VWatchiethis was a very nice write up and was thoroughly illustrated.  Thanks for the mention by the way.  I had read through this shortly after it was posted and responded with a like but have been very busy here getting ready for winter, as well as several extra work related responsibilities.  Your mentioning a watches rate increase with vigorous activity from this thread, as well as another one you also authored may need some further discussion.  I didn't want to reply without giving it some consideration but all I can come up with is either,

Incompatible breaking grease.  A grease that is only as slippery as is mechanically necessary.  This has always sounded like Voodoo to me.  I have recently purchased some 8217 grease recently recommend by Mark.

 

Incorrect mainspring (applying to much force against the inside of the barrel).  Possibly intended for a barrel of a larger diameter.

I would think that either way, for whatever reason, the two situations should be observable on the beach.  The idea about the hairspring sticking may be harder to verify without the dynamics previously mentioned.  Have you had time to look into this?

PS,

I have also just recently looked at several Vostok watches.

Shane 

 

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On 9/19/2022 at 1:43 AM, Shane said:

I would think that either way, for whatever reason, the two situations should be observable on the beach.  The idea about the hairspring sticking may be harder to verify without the dynamics previously mentioned.  Have you had time to look into this?

Hey, thanks for your kind words @Shane 🙂 and sorry for the late reply as I missed your post. To answer your question, yes and no. There's an ongoing discussion in the thread "Why does the rate start to rush when I work out?" We'll see how much work and interest I and others are willing to put into it.

The type of automatic winding (a slipping mainspring) that we have in most (all?) watches today is IMO just a half-decent construction. I'm surprised someone hasn't come up with a more robust construction. It's probably extremely difficult or someone would already have come up with something new.

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    • yes I agree this is not a long term solution and I have written a letter to santa telling him to bring me expensive greases and oils for christmas...(my how ones desires change with age) and this was more of an exercise in getting an old cheapo banger stripping it, and putting it back together using my 150 euro microscope...(yes I am investing in tools for this) which has been a great help to my eyesight as squinting down a loupe is just not for me.  I would rather got the THX 1138 route and remotely manipulate things whilst looking into its rather largeish screen. Rather than looking directly at them via a loup, it works for me, as I have high visual and spatial awareness so grabbing things with tweezers sight unseen but on screen has been pretty easy for me. But it's crap for filming as the microscope is so low you can't get your hand in under it with a screwy so your having to drag it out of vision all the time to nail somehting down. but I do not intend to start youtubing either on my van fixes or my watch repair as no one wants to hear a Yorkshireman chuntering throwing tools about and swearing all the time about stuff... But It would probably go viral as the kids would have field day mashing it up probably. but I do not want to be a tv star, I leave that to those good at that... But I see you have been following and replying to my posts and I thank you for your interest...But of course i am going to buy the oils mark recommended as if you want to seriously service a watch you need both them and an ultrasonic cleaning machine... But as it stands I have spent more on tools and equipment than on watches...but I will be ready for the gem of a seamaster or rolex when i find it in a thrift store... But my scores so far are 7009A achieved, although the intermediate date wheel was totally banjaxxed in both the movement I bought and the donor movement (i am now the man to see for 7009a parts) and i am begging anyone and everyone for their contribution of one of those. Although I have to tell the truth and I did destroy the first original balance in the 7009A with my hamfistedness but all in the learning curve. but the problem there is that the hour wheel spins loose probably because the intermediate date wheel is not there to hold it...but the second hand ticks along like a champion and the magic lever is working as it should so when I get the wheel it should be wearable... and The Unitas 176 Achieved in the Cauny 17 rubis Antimagnetic which now works and keeps pretty good time with just 3 in 1 and car grease, but like you so rightly said probably not for very long... But I worked it out that if I greased the CV joints with braking grease and the rest of the grease points on my Renault master van, then the whole vehicle would be worth more than a Ferrarri...
    • You got that right! I don't remember what Alex suggests in his lubrication video but I seem to recall it wasn't going out and purchasing $200 worth of Moebius oils for your first foray into watch repair. Rather than "car grease" you might look at picking up some Molykote and Singer sewing machine oil might be better than 3-in-1 for doing jewels.  While your "freshly lubricated" scrap movements may seem just fine after treating them with 3-in-1 and car grease, the 3-in-1 will likely dry out and get gummy after a while. One of the guys here was in the process of assembling "starter kits" with small quantities of good watch oils but I don't know where he is on that project.  
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