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NCRich

How to freeze the 6 oclock subdial on ST19 (plus keyless)

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NCRich

I have copied this from the other RWG and rescued it from the evil that is Photobucket.  This is the best guide to doing this that I have found and how I learned to do it.  I may use slightly different tools (levers instead of hand pullers, etc,) the concepts are the same.  It also has a pretty good guide to resetting the most common keyless problem.  Remember that you remove the stem in the winding position.  Anyway enjoy Toad's Guide to the ST19.

Hi folks,

 

My usual preface: I am not a watchmaker...but a hack. There are some things I'm going to do that a watchmaker would shudder at. There is also some dust on the pics presented that would make Pugwash, Zig and others puke. The lighting on the pics is terrible...sharpness is bad...composition terrible...yada yada yada. BUT, I did do this work inspired to make a tutorial to help others out including my bud HackR who is having some keyless works problems right now.

 

I was originally inspired to do this by Ajoesmith who's tutorial on the Replica Collector site gave me all the info I needed for the subdial freezing.

The Keyless Works info came from a combination of the ETA 7750 tech guide as well as some other tech docs I have kicking around.

Thanks to RWG...the place to be, I was inspired to go the next level in watch fixing (beyond changing straps and sizing bracelets). By the way, you'll see 2 different watches used in this tutorial because pics the best pics were found using a combination of documented efforts.

Without further delay...excuse the crappiness...and lack of prose...we're into the business lickity-split. Oh...and yeah...my fingernails need clipping...useful for peeling dial strips though.

MOVEMENT: Sea Gull ST1902 (aka Venus 175, Lemani Manual Wind)

PROBLEM:

 

  • 6-o-clock subdial on the ST1902 is mated to the hour wheel instead of being a chrono totalizer function
  • Crown would not insert properly or wind movement
  • Movement would not run


    SOLUTION:
    • Freeze 6-o-clock subdial
    • Check keyless works

1.jpg


2.jpg

Remove the Stem

With the crown unscrewed and in the winding position, I use my springbar tool and depress the stem release button gently, while turning clockwise and pulling out the crown.


3.jpg

Remove movement holder screw #1


4.jpg

Remove movement holder screw #2


5.jpg

Remove both movement holder tabs


6.jpg

Remove the movement gently on a decasing pad


7.jpg

Mount movement in movement holder...note chrono second hand is not pointing at 12-o-clock

NOTE: 6-o-clock subdial hand is already frozen and sort of reset already (not pointing right at 12-o-clock in the pic...it has since been resolved). On the watch "out of the box" it will be parallel to the hour hand so it can look kind of funny as none of the other chrono functions will be running but the 12 hour totalizer is pointing to the hour of the time unless it's frozen.

Sea Gull had talked about making a true 3 register chrono function ST19, but have yet to do so.


8.jpg

Install Bergeon 6938 dial protector


9.jpg

Use Bergeon #1 hand remover tool to remove the chrono second hand (or use a generic cheapy)


10.jpg

Chrono second hand off

NOTE: Dust on dust on dial protector. This is to ensure similar conditions to Chinese assembly plant to make sure the movement operates properly as per factory conditions and specs. :p

After removal of the chrono second hand, remove the minute and hour hands using the same tool. For the subdial hands, you will need to use a carefully dressed hand tool (i.e. filed) or a Bergeon #6 I believe (I don't have the #6) because the small hands are pretty tight to the dial so you need thin claws on the puller to grab the hands effectively.


11.jpg


12.jpg

Unscrew dial feet (2 sets)


13.jpg

Dial feet screw


14.jpg

Dial removed reveals cover plate

Arrows indicate cover plate screws that need removal.


15.jpg

Screws removed


16.jpg

Note the faux chrono 6-o-clock subdial is in fact merely hand attached to a wheel with a pinion connected to an intermediate gear that is connected to the hour wheel.

To Freeze the Subdials: These 2 brass wheels are merely removed with tweezers as the cover plate holds them in place.


17.jpg

Wheels removed...note grease / wear marks


18.jpg

Add dial strips (double sided tape) where the pinion wheel sits


19.jpg

Stick pinion wheel into dial strips


20.jpg

Note buggered keyless works


21.jpg

Proper Keyless Works

If you note 2 pictures up, the setting lever jumper is not correctly hooked onto the setting lever. This likely was caused from pulling the stem out in the time-setting position and popping things out place. You can also bugger the keyless works by pressing the stem release too hard.

To reset the keyless works, merely hook the setting lever jumper back on the setting lever post.

I also had the problem that the winding pinion fell out somehow. To put this back in, use a screwdriver or springbar tool to push the spring loaded sliding pinion to the left, and drop the winding pinion back in place so the teeth on the face of the winding pinion mate with the teeth on the face of the sliding pinion.

Easy peasy.

Once the keyless was reset, everything worked properly. I was able to reinsert the stem properly and proper function allowed the movement to run again instead of being locked in the time setting position. I was lucky!! On other movements (not the ST1902), you might have to re-position the yoke between the winding and sliding pinions to reset things.

Put the cover plate back on...and install the screws.

Screw back on the dial using the dial feet as guides...or mount using dial strips / dots if the feet break off or you change to another dial without feet. 3 register movements are easy as you have 4 small reference pins to ensure proper centering of the dial. Movements with date functions help as well...but can be a bit finicky to centre still.

It is harder to center the dial on movements without dial feet when you don't have additional registers and will have to use dial hour markers lining up with stem insert holes or other movement references to ensure proper centering.


22.jpg

Dial back on, tighten dial feet


23.jpg

Mount running second hand

I use Rodico to pick up the hands.


24.jpg

Use hand pressing tool to mount hands.


25.jpg

Do the other subdial hands


26.jpg

Mount the hour and minute hands

The beauty of mounting the hour and minute hands on a movement WITHOUT a date feature is that you don't have to worry about the position of the hour and minute hands as they can be manually set when setting the time with no "rollover" coordination with midnight to worry about...so just plug them in, set the time and go!


27.jpg

Check for hand clearance

If the hands are pressed too deep, are not parallel to the dial surface or are bent, they will hit each other. you may have to try and level out the hands with your hand pressing tool or try and straighten the hands if they are bent.


28.jpg

Mount the chrono seconds and admire your work

NOTE: The chrono seconds hand does not mount around anything, but has a post that fits inside the pinion. This is best positioned through a loup using Rodico and then pressed once centered correctly.

As well, you'll see the chrono second hand is properly pointing to 12-o-clock. This is a bit finicky to get set properly and WILL take a bit of trial and error so keep that loupe and hand puller handy!!

ANOTHER NOTE: When installing the chrono second hand, you should make sure the stopwatch is not running, and that the chrono reset pusher has been pushed otherwise you will find your perfectly centered hands are NOT pointing to the top after you install everything.


29.jpg

Re-case movement


30.jpg

Put back in movement holder tabs and screws


31.jpg

Re-insert stem

Blow off dust...Rodico off finger prints, oil and grease. Grease gasket.  Put case back on.

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Simonix

Really useful this.

It is what I used to learn how to do my Paul Newman last year.

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Nikosaldente

Awesome find @NCRich :D

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Glaude

:thumbsup: 

Thanks for taking the time to post it correctly here !

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aitcharGMT

Very useful, thanks for this tutorial.

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als86

Great write up thanks, having just purchased 2 of these watches which part is required to be moved in order to release the wound spring tension?

I think one of them I have could be overwound as it only runs with the crown out and turned clockwise quarter of a turn…..if I release the crown from the twisted position it only runs for 5 seconds….which is odd.

Thanks in advance

 

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als86

Ah……found it but that wasn’t the issue. 

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NCRich
9 minutes ago, als86 said:

Ah……found it but that wasn’t the issue. 

You broke the click spring.  Most common problem with this movement.

 

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als86
7 minutes ago, NCRich said:

You broke the click spring.  Most common problem with this movement.

 

Thanks @NCRich I’ll have a read of that however it does work now but only when the watch is upside down :blink:. As soon as I turn it over the second hand stops as does the balance wheel stop spinning so I’ll reach out to the TD as it’s only a week old and first time it’s been wound. 

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NCRich
7 minutes ago, als86 said:

Thanks @NCRich I’ll have a read of that however it does work now but only when the watch is upside down :blink:. As soon as I turn it over the second hand stops as does the balance wheel stop spinning so I’ll reach out to the TD as it’s only a week old and first time it’s been wound. 

Hmm.  I must have read it wrong.  Could the stem be too long?

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als86

Appreciate the info @NCRich I’m very new to the vintage world and manual wind movements so any info is always grateful. 
 

I found the click spring as mentioned but it seems ok and spring still operates. I have oiled a few moving cogs and probably inadvertently nudged the regulator arm so will keep an eye on how it runs over the next 24 hours but for now it is at least running.

Thanks again. 

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Jasonbaylee

NCRich, very kind of you to share with us n all the more so with the pain taking shots that u had to momentarily freezed your movements!
Please convey thank to the person that was assisting you for these photography! Great shots!
Very educational & informative thread!

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Connery77

Thank you so much for this post.  I used it to freeze the subdial on a new Omega Speedmaster I just got.  Thank you!

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