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  1. Horlogerie EU based Professional Watchmaker Aug 13, 2015

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    Repair of an Omega 30T2 handwind movement


    The watch was sent in for servicing and possible repair. Included in the package was an extra movement, but a quick inspection revealed that the balance and cock were replacements and not 30T2 caliber parts, therefore unusable. The rest of the spare movement looked ok, so I put it to one side and checked out the watch.


    My initial inspection indicated that the balance staff was broken, movement would run dial down but not dial up, and when I moved the balance with the twezers it flopped around – a sure sign of a broken staff.

    Disassembly and inspection


    First up was the removal of the balance cock, to check the condition of the staff. Much to my surprise the staff was just fine, both pivots were there and looked ok, closer inspection revealed some concerns, the staff was replaced and was too short, the reason it appeared broken on my initial inspection, a closer inspection showed that the roller table was cracked, most likely a result of the staff replacement. So clearly someone had been here before and did some questionable work, wonder how the justified the replacement staff that resulted in a non-working watch.


    With the damage to the roller I was reluctant to remove the staff in case the roller ended up unusable, leaving the customer no further ahead than when he sent the watch in, in effect a non-working watch. The jewels are fixed in place and non shock absorbing and there was no way that I could move either of the jewels in attempt to eliminate the excessive end shake.


    Given the high cost of replacement parts for this movement (the same day I was doing this job, I happened to have noticed a 30T2 balance complete for sale, at $400.00, ouch) I had to find a solution. If replacing the staff was not an option, and moving the jewels wasn't either, then the only solution I could come up with was to slightly trim the bottom of the balance cock foot, thereby moving the whole cock downwards and correcting the defect. I ran all the scenario's, options, and my findings past the customer, and he agreed to the balance cock re-work.


    Here is a view of the balance with the top cap jewel removed, you can see that the pivot is no where to be seen, it's situated down below the bottom level of the hole jewel.

    [​IMG]


    Here's a closer view of the cracked roller table.

    [​IMG]

    Barrel Bridge arbor bearing damage/botched repair


    As I took apart and inspected the rest of the movement, I found more botched workmanship. The barrel bridge bearing for the top barrel arbor pivot was worn, signs are the worn brassing area just at the top of the photo, and of course the botched repair by someone in attempt to correct the wear, all they have done is take an egg-shaped worn hole and squared off the inner edges. Not a good bearing surface if you want to ensure smooth winiding and proper working of the mainspring.


    Top view of the punch and hammer damage.


    [​IMG]


    Bottom view of more damage.


    [​IMG]


    The customer was notified of the damage, and since I had a spare movement I offered to simply swap the barrel bridges, but reminded him that the serial numbers would change due to the serial numbers being engraved on the barrel bridges. As an alternative to keeping the original bridge in place, I suggested replacing the worn bushing by making a new one, he agreed because serial number retention is important on a classic collectors watch.


    So I went ahead and reamed out the damaged hole. Work is done on the jewellers press to ensure a perfectly aligned and upright hole which to install my new bushing into.


    [​IMG]

    [​IMG]

    With the hole enlarged enough to allow fitting of a new bushing, you can see the burr left over that I carefully cut away by hand with a 45 degree cutter.

    [​IMG]


    I made a new bushing on the lathe, cut it off and fitted it into the new hole.


    Here is a view of the barrel, new bushing, and barrel bridge.


    [​IMG]


    The bushing is pressed home on the staking tool, and secured with a tiny bead of loctite, then the arbor is test fitted multiple times while carefully and slowly reaming the hole until the arbor just fits, then the hole is hardened with a smooth broach and test assembled. With a free turning barrel, with the correct end and side shakes, the job is completed.


    [​IMG]


    Here is a view of the fitment to the underside of the bridge.


    [​IMG]


    The repairs worked out well, the watch runs, in all positions now, I had to make a few minor adjustments to the cock height with the watch running and observing the results on the computer screen of the escapmemnt analyzer, and in the end I was able to get a reasonable rate in all positions that while not within COSC specs, are perfectly acceptable given the alternative, a non-working paperweight. After 24 hours sitting dial up on the bench, it's less than 1 minute out from the atomic time signal, not bad at all, and granted when worn the dynamic movements are going affect the rate, but overall the watch is working and certainly wearable. I think the customer will be pleased when he gets it back.


    Here is a view of the watch torn down before cleaning.


    [​IMG]


    And since we have only been looking at movement photo's, it's appropriate to end the post with a view of the watch in question.

    [​IMG]


    [​IMG]


    Thanks for reading.

    British Horological Institute Professionally Qualified Watchmaker
    www.roberthoran.eu
     
    Edited Aug 22, 2015
    felsby, dougiedude, Mothra and 12 others like this.
  2. wsfarrell Aug 13, 2015

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    Most impressive, thanks.
     
  3. Ludi Aug 13, 2015

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    Impressive work indeed !!! So glad you manage to get it fixed, which was a bit of a challenge considering what I believe to be an Omega caliber 256 balance was initially mounted on it. I can't imagine the trouble it was to adapt it into a 30T2 movement ... for such a bad result :D

    Well, next time, I will certainly check the movement prior to buy... there is a lesson here guys :whistling:

    May I emphase the excellent communication all along the process :thumbsup: ... excellent skills, top notch guy, what else can I say :p

    Thank you very much Robert :cool:
     
    marturx and oddboy like this.
  4. Joe K. Curious about this text thingy below his avatar Aug 13, 2015

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    Interesting. Another solution to the balance issues would have been for the client to try and source a correct balance staff and roller table. These do occasionally show up for sale on eBAY or can be found through WTB ads on watch forums.
     
    Archer likes this.
  5. tpatta Happily spending my daughter’s inheritance Aug 13, 2015

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    Great post. Thank you for the pics and commentary.
     
  6. Horlogerie EU based Professional Watchmaker Aug 14, 2015

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    The customer had already sourced, bought and paid for, a complete spare 30T2. Unfortunately the spare movement was botched and had the incorrect balance and cock and so wasn't usable. With unlimited funds, replacing the balance is indeed a possible solution, but with projects like this, all factors have to be considered and the best solution is typically somewhere in the middle, that being: what is the value of the watch vs how much more has to be spent on the repair, and consider as well that sourcing another balance may end up with another unusable part and more money spent.

    In the future if a new complete balance is sourced, it could be installed and may only need slight trimming of the pivot lengths to fit (because it's possible that this cock is also the wrong part) or even better, a balance assembly and cock could be sourced to replace both parts.

    Considering the number of botched repairs on both movements (roller table, balance staff, cock height, incorrect balance, incorrect cock, botched barrel bridge repair) I suspect that the odds of finding used parts or complete 30T2's in good condition are not great.

    Thank you for the positive feedback.
     
    Edited by a mod Jul 10, 2021
    TNTwatch likes this.
  7. marturx Aug 14, 2015

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    Very educational & interesting reading!

    I'm fascinated by post like these. I always read @Archer posts with a mix of horror and great joy :p
     
  8. esspee1200 Aug 16, 2015

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    Great read. Thanks for sharing.
     
  9. reficul_x Aug 16, 2015

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    Very nice pictorial. Always love these posts and appreciate all the work done for this post.
     
  10. reficul_x Aug 16, 2015

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    And throw in a pair of original sword hands, this will be a winner.
     
  11. lillatroll Aug 17, 2015

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    As someone with no practical skills it's always fascinating to read stuff like this. An enjoyable read to start the day with.
     
  12. Horlogerie EU based Professional Watchmaker Aug 17, 2015

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    Glad you enjoyed it, thanks for the feedback.
     
  13. Ludi Aug 19, 2015

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    MoD hands they are ... fine by me ;)
     
  14. Ludi Aug 20, 2015

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    Found a picture of my initial unpleasant surprise :confused:

    [​IMG]

    Notice the wrong balance system which I suspect to belong to a caliber 256 (?). Why ????

    Again, I should have asked the seller pictures of the movement prior to wire the money :rolleyes: ...
     
  15. vinn2 Aug 20, 2015

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    good job. liked the photos
     
  16. KIMBER Aug 20, 2015

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    Very nice work there. Thanks for sharing with us.