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Why I like jewels instead of bushings...

  1. Archer Omega Qualified Watchmaker Apr 22, 2014

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    Got this Seamsater with a Cal. 332 in a while back - shot of the movement:

    [​IMG]

    As I remove some automatic parts, I see some damage on the plates:

    [​IMG]

    Look a little deeper, and I can see this bushing is very worn:

    [​IMG]

    The corresponding bushing in the bridge is also worn:

    [​IMG]

    The lack of debris inside the movement tells me this wear has been there for a while, and the last person to service this did not bother to fix the problems...so I guess that falls to me.

    I'll start with the main plate:

    [​IMG]

    The Horia tool makes this job pretty easy - here pushing out the old bushing:

    [​IMG]

    Omega still supplies the bushings, so here is the old and new beside each other:

    [​IMG]

    Pressing the new one in:

    [​IMG]

    Much better:

    [​IMG]

    Now for the bridge, the same process is used:

    [​IMG]

    All done:

    [​IMG]

    If these were jewels, they would likely be fine and no damage would have been done to the movement.

    Watch is running well now...this is actually a photo from before I started, but I didn't do anything to the watch cosmetically.

    [​IMG]

    Cheers, Al
     
  2. Stewart H Honorary NJ Resident Apr 22, 2014

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    Al. Is the Horia that much better than the Seitz? If so, are the pushers etc. interchangeable between the two systems?
     
  3. Archer Omega Qualified Watchmaker Apr 22, 2014

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    I have a Seitz set and I rarely use it. Most jobs are done easily with the Horia tool, and it's uses go far beyond just jewelling.

    The Horia tool comes in different sizes with the stumps and pushers in different mounting diameters, so it really depends on what tool you get if you can use your Seitz items with the Horia. Mine is 4 mm on both upper and lower, and this allows me to use a stump in both places if needed also - for example for pressing on a chronograph or sweep seconds drive wheel:

    [​IMG]

    What I didn't show above is how the Horia tool can be used to measure the depth setting of the jewel or bushing. So before I push the old jewel or bushing out, I flip the plate over as if I was pushing it in place, and bring the tool down flush with the jewel/bushing, and note where it is on the micrometer scale. I then flip it over, push the old one out, then mount the new one, and I can just push it in until it matches up to where the old one was. In most cases that will give you the correct end shake, but if not it will be close and you can adjust from there.

    Adjusting end shake on wheels with the Horia tool is very quick and easy - I can adjust something by 1/100th of a mm very easily - it only takes seconds.

    They are not cheap, but I use mine pretty much every day for something.

    Cheers, Al
     
    NT931 likes this.
  4. JohnSteed Apr 22, 2014

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    Quite thorough work Al. Nice details I've not seen previously.

    :thumbsup:
     
  5. ulackfocus Apr 22, 2014

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    Al, is it possible to replace those bushings with jewels? If so, do they make jewels that size and is there an adaptation that would need to be done to fit the jewels in place?
     
  6. Archer Omega Qualified Watchmaker Apr 22, 2014

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    Omega does not supply an equivalent jewel for this location. Of course it can be done, but it depends on how "original" you want the watch to be, and how much you want to spend.

    On the originality side, considering how you guys react to something as common as a particular plate being different in colour from others, I assume that replacing bushings with jewels would not be acceptable for many here. If we look at the guys who collect vintage US pocket watches, even replacing a bezel set jewel (getting very hard to find theses days) with a friction fit jewel is near heresy. In fact if you use a jewel that is of the same type and size, but doesn't match in colour (the shade of red) they will frown upon it.

    So technically I could maybe find a jewel that would fit the pivot, but the chances it would fit the hole in the plate is not high. This would now require modifying the plate to make the hole larger maybe, or possibly create a setting on the lathe that you can press the jewel into, then press that assembly into the plate. This all takes time, and time is money.

    Lots of things are possible, but it depends on the situation what option is chosen.

    Cheers, Al
     
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  7. Ru4scuba Apr 22, 2014

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    Great pics Al...thanks for sharing!
     
  8. Trev The Architect Staff Member Apr 22, 2014

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    Those gouges on the plates ended up a lot deeper looking than I would've expected, interesting. I wonder how long it had been grinding?
     
  9. Archer Omega Qualified Watchmaker Apr 22, 2014

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    They are fairly deep. When you consider the angle that the part was off perpendicular due to the oval holes in the bushings, you can certainly see how much damage it can do.

    Hard to say how long it would have been wearing the plates, as the service history is unknown, and as I mentioned there was really no debris from the plates inside the watch, so it had been cleaned since the majority of the wear had occurred.

    Cheers, Al