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Discussion Starter · #1 · (Edited)
This is my second post in this forum and I hope you will find it useful. I enjoy watches and I am interested in the inner workings of movements, but not only I am not a professional I am also a beginner. As an amateur, I am bound to make big and small mistakes, feel free to critic.

In this post I am going to disassemble a Raketa 2609.HA (or NA using latin characters, as some if not most of you will know). The purpose is to get a better understanding how this movement was designed and works.

Some of the Raketa 2609.HA technical specifications can be found in: http://raketa.com/en/mouvments/raketa-2609-ha/.

The title for this post was inspired by a post by marc_wl intitled "The Anatomy of a Vostok" (https://www.watchuseek.com/f54/anatomy-vostok-68330.html) in this forum.

As you will see the photography is not great. Some of the photos were taken with a microscope camera and others with a Canon PowerShot SX200IS. I definitely would like to be able to take better pictures so all advice regarding lighting and photography techniques would be very much appreciated. Also I would be interested to know which is a good camera to take nice macro pictures of movements and watches and that could also be used with the microscope (I have a Canon adapter).

For beautiful pictures of movements and their parts I recommend the Naked Watchmaker, but you guys here probably already know this.

I took this movement from a raketa watch I bought on ebay. I am not going to show here how to remove the movement from the case I will just say this watch case required the movement, contrary to what is usual, to come out through the front. There is a blog that shows the decasing of the 2609.HA and also coves disassembly and assembly but again I am not allowed to post the link.

A nice video regarding the assembly of the Raketa 2609.HA can be found here: https://www.youtube.com/watch?v=cbWoYjdzamY.

The Raketa 2609.HA is a movement with a center second hand. The following picture shows both sides of the movement.

movement_2_sides_small.JPG

It is possible to see that the movement has 4 shock protection jewels: 2 incabolic in both sides of the balance assembly and 2 (which I don’t know the name) as the escape wheel’s top and bottom bearing.

I will do the desassembly in the following order:
1. motions works
2. keyless works
3. ratchet wheel, crown wheel, click.
4. balance assembly and pallet
5. train of wheels and barrel


The next figure shows the movement’s train of wheels.

movement_without_wheels_bridge_croped_small.JPG



It can be seen in the previous figure that the movement was designed such as to the fourth wheel being placed in the center and going through a hollow second wheel.

The next figure shows the barrel, second wheel and its bridge.

movement_showing_second_wheel_bidge_croped_small.JPG

The next figure shows both sides of the main plate.

main_plate_both_sides_small.JPG


Jewels
I count 11 bearing jewels as follows: 5 on the main plate for the second wheel, third wheel, escape wheel, pallet and balance. 1 jewel on the second wheel bridge for the second wheel. 3 jewels on the wheels bridge for the third, fourth wheel and escape wheel. 1 jewel on the pallet bridge and 1 jewel on the balance cock.

Then we have 2 pallet jewels, 1 impulse roller jewel and 2 balance jewels. The grand total is then 16 jewels.


The train of wheels
The next figure shows the wheels of the train of wheels.

train_of_wheels_ig.JPG


The wheel teeth and pinion leaves are as follows:

Barrel Second Third Fourth Escape
Wheel teeth 72 80 75 80 15
Pinion Leaves 12 10 10 8

It is known, from the technical data, that this balance wheel frequency is 18000 vibrations per hour (vph) or bits per hour (bph) or 18000/3600=5 bits per second (bps) which is equivalent to 2.5Hz since in each oscillation there are 2 vibrations. Remember also that 1 hertz can be defined as 1 cycle per second and 1 cycle corresponds to 1 oscillation of the balance.

Knowing the balance wheel frequency and the number of teeth of each wheel and leaves of each pinion is possible to calculate the time each wheel takes to complete a revolution.

Every second, the time for 5 vibrations, 5 teeth of the escape wheel advance. Since the escape wheel has 15 teeth and each teeth is stopped twice, it follows that one revolution of the escape wheel takes 15/2.5=6 seconds.

Because the escape wheel's pinion has 8 leaves, for every full rotation of the escape wheel the fourth wheel advances 8 teeth. Hence, every 6 seconds the fourth wheel advances 8 teeth. The fourth wheel has 80 teeth and so it takes 60 seconds (6*80/8=60) for one revolution of the fourth wheel.

The fourth wheel pinion has 10 leaves and rotates once every 60 seconds, so 10 teeth of the third wheel advance each minute. This wheel has 75 teeth, so it does a full rotation once every 7.5 minutes.

The third wheel's pinion has 10 leaves, consequently the second wheel advances 10 teeth every 7.5 minutes. As the second wheel has 80 teeth it can be concluded that the second wheel rotates once every 60 minutes (7.5*80/10=60).

Finally, one revolution of the barrel takes 72/12=6 hours, so depending on how many full rotations the barrel can do from fully wound to fully unwound the power reserve can be worked out. If, for example, it can have 7 full rotations then the power reserve will be 42 hours. The power reserve of this movement is 40 hours, so 7 full rotations should be about right.

Note also that the frequency of the balance wheel, assuming that a full rotation of the second wheel takes 1 hour, can be calculated as (80/10)*(75/10)*(80/8)*(2*15/8) = 18000bph.


The motion works
The motion works are made by the cannon pinion which has 12 leaves, the minute wheel with 32 teeth, minute pinion which has 8 leaves, and the hour wheel with 36 teeth. This wheels are shown in the next picture.

motion_works_ig.jpg

Applying the same logic as before it follows that since the cannon pinion rotates once per hour that the minute wheel takes 32/12 hours to rotate and takes (32*36)/(8*12)=12 hours for one revolution of the hour wheel.


Keyless works

The next figure shows the keyless works in the winding position and in the hand setting position.

keyless_works_pos1_and_pos2_small.JPG

In the winding position, where the stem is totally pressed in, the slidding pinion is in a position such that the winding pinion is engaged with the crown wheel so the movement can be wound.

In this position, when the stem is turned clockwise the slidding pinion makes the crown wheel rotate which in its turn engages the ratchet wheel and wounds the mainspring.

The click pevents the ratchet wheel to turn backwards which makes the mainspring to correctly unwind. The crown wheel, click and ratchet can be seen in the next figure.

Ratchet_wheel_click_cown_wheel_croped_small.jpg


If the stem is turned anticlockwise the slidding pinion dos not move thanks to its Breguet theeth.

When the stem is pulled out, the setting lever turns on its pivot and pushes the yoke which also pivots and moves the sliding pinion to the hand setting position. In this position the slidding pinion engages with the intermediate setting wheel.

The intemediate setting wheel then engages the minute wheel which engages with the canion pinion and hour wheel.

When the stem is pessed in and goes fom the hand setting position to the winding position, the slidding pinion is returned the position, where it engages with crown wheel, by the yoke spring which puts pressure on the yoke.


The winding train
The winding pinion which has 16 teeth, the crown wheel which has 28 teeth and ratchet wheel which has 53 teeth make the winding train. This 3 wheels are shown in the next picture.

winding_train_resized.JPG


For each 28/16=1.75 turns of the winding pinion the crown wheel has 1 revolution and for 53/28 turns of the crown wheel the ratchet wheel has 1 revolution. So for each (28/16)*(53/28)=(53/16)=3.3125 turns of the winding pinion the ratchet wheel has a full rotation.

If it is assumed as before that takes 7 full rotations for the main spring to go from fully unwound to fully wound, then about 23 to 24 full turns on the winding stem are needed to do so.


The hand setting train
The hand setting train is made of the sliding pinion which has 13 teeth, intermediate setting wheel wich has 15 teeth, cannon pinion which has 12 leaves, minute wheel, minute pinion and hour wheel.

One revolution of the cannon pinion means the minute wheel advanced 12 teeth, the intermediate setting wheel advanced 12 theeth and the sliding pinion advanced also 12 teeth.

So, since the sliding pinion has 13 teeth, when in the setting position an almost full turn of the stem makes the hands of the watch advance 1 hour.



And this ends the post. Hope you enjoyed it.
 

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Welcome to the forum, comrade, and thanks for your attempt to help us understand how this iconic Raketa movement works. Can't wait to see the pictures.

Interesting analysis of the timing of the wheels, maybe you would be interested in this: https://www.watchuseek.com/f10/analysis-raketa-2609-2623-24-hour-movements-894141.html

No soviet watch that I'm aware of uses a shock-proofing assembly on anything other than the balance wheel. This makes sense since only the mass of the balance wheel has enough momentum energy when brought to a abrupt stop to snap the bearing shaft if not allowed to move slightly by the shock-proof assembly. The soviets used those tiny springs instead of screws and plates to hold cap stones in place at various other bearing locations. The bearings themselves were rigid.

Have a look here: https://www.watchuseek.com/f10/soviet-watch-quiz-vi-4568377.html
 

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Discussion Starter · #7 ·
Thank you very much schnurrp. The analysis on the conversion from 2609 to a 24h movement is very interesting. The same for the shock protection. So now we know that escape wheel bearings are not shock proof.
 

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Just picked up this Big Zero off eBay, so the deconstruction of the movement is super interesting. Plus the advice on assessing movement health - thanks!! So far, mine seems to be tracking well. It’s a fun and funky watch, and inexpensive...
 

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Hello Friends, I dunno if this is the right place to ask. But I recently bought a Raketa 24h Antarctic with this Movement (according to seller info) off ebay. And although I really like the look of it it seems to run dead within a day after winding. Is that normal for this core? Is it broken/worn out/possible fake?

Much appreciated
 

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Hello Friends, I dunno if this is the right place to ask. But I recently bought a Raketa 24h Antarctic with this Movement (according to seller info) off ebay. And although I really like the look of it it seems to run dead within a day after winding. Is that normal for this core? Is it broken/worn out/possible fake?

Much appreciated
welcome. So the watch runs for less than 1 day on a full wind? When you wind, how many turns with your fingers do you do? Should be close to 20-25. Not 10. Does the watch keep accurate time?
 

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Really great write-up here. My Raketa Big 0's movement is loose in the case. I need to replace the two case screws because the ones in there now have the wrong size head to hold it in place properly. Do you know what size screw is the right one? Thanks!
 
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