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On My Bench - Seiko 7A28-7039

  1. ExpiredWatchdog Nov 21, 2019

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    Regarding your oil selection, I did an ETA two hander a few months ago. The spec sheet called for Moebius 9014 for the pivots (including one of the rotor pivots). Somewhere I read that it's about halfway between 9010 and 9020, which makes sense; 9020 being less viscous than 9010.

    I found the quote from Ofrei's website "Thinner than 9010, comes in the 2 cc size bottle. Moebius 9014 is a mixure of 70% Moebius 9010 and 30% Moebius 9030, and used for lower temperatures. Viscosity of 0.98 stokes at +20 degrees celsius, provides good lubrication until -35 degrees celsius."

    So it sounds pretty close to 9000.

    After the challenge of assembling a two hander (with four bushings in the motion works plate) I can't imagine the difficulty of your job. I'll try to avoid it.
     
  2. JimInOz Melbourne Australia Nov 23, 2019

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    After a few days testing I'm calling it done.

    Keeping time to within one second of my phone clock.

    Timing21NOV1753.JPG Timing22NOV1650.JPG Timing23NOV1612.JPG Timing24NOV1606.JPG

    So tomorrow it's off back home to it's patient owner.

    Now what's next?

    Oh yes, the Tudor 390.

    :(
     
  3. verithingeoff Nov 24, 2019

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    [QUOTE="JimInOz, post: 1376724, member: 1543"


    Now what's next?

    Oh yes, the Tudor 390.

    :([/QUOTE]
    :cool:
     
  4. Deafboy His Holiness Puer Surdus Nov 24, 2019

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    What's the app?
     
  5. JimInOz Melbourne Australia Nov 24, 2019

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    Not really a timegrapher style app, just one of the Emerald Sequoia time apps.

    I set the watch to the time, take a shot, wait 24 hours and take another etc. Then see how far out the second hand is each day.
     
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  6. destroid Nov 24, 2019

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    I use that Emerald Sequoia app to set my watches too as the phone time tends to be off. They have a nice orrery app too:
    B0650362-25A5-4ADB-842E-2D0300D443BE.jpeg
     
  7. Riba Feb 3, 2020

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    Thanks for documenting the process along with the photos! I got one comment - on the picture above the center leaf spring is missing which is often the case on these movements. There is no photo of the assembled movement so I am not sure if you sourced one or were not aware that one should be there.

    Check this photo, it is the leaf spring in the middle (bent out of shape in this case). Hope it helps!

    7a28.jpg
     
  8. JimInOz Melbourne Australia Feb 3, 2020

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    Quite correct!
    It was the second component I removed (after the battery) and it was re-installed as the last thing after checking function (and checking again).

    I think it can bee seen in the parts tray in some shots.
     
  9. Riba Feb 3, 2020

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    Got it, apologies for the false alarm!
     
  10. imfagent449 Jun 27, 2020

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    I guess that battery powered doesn't always mean that it is easier to service.

    I have two IWC mecaquartz watches- I love them but pray that they don't break down.
     
  11. inchpincher Has your missing inches Jun 28, 2020

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    @JimInOz Really enjoy your write ups, especially this as I’ve been collecting a few Grand Quartz lately as I see them as such good value for money. What kind of service interval would you recommend on something like this... 10 years?
     
  12. JimInOz Melbourne Australia Jun 28, 2020

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    Hard question to answer.
    If it's clean, has fresh oil and regular battery replacement it could tick forever.
    If the watch has been well treated and lived in a begnin environment, I'd say 10 years would be OK.
    Bear in mind, if it hasn't been serviced recently/properly or treated with kindness, a lesser period or an immediate service would be wise.
     
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  13. inchpincher Has your missing inches Jun 28, 2020

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    Thanks, I wasn’t fishing for a definitive answer btw, just your opinion having knowledge of quartz in general which we don’t see much of on OF. It’s good to know they are quite serviceable and not just disposable movements. However I may stay away from the chronographs if I want to remain friends with my watchmaker. Thanks again for the glimpse behind the curtain...
     
  14. Archer Omega Qualified Watchmaker Jun 28, 2020

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    Generally speaking, I only recommend servicing (meaning full disassembly, cleaning, oiling) of a quartz watch when there' a problem. Quartz watches generally are not subject to the same level or wear that mechanical watches are, so require far less frequent servicing in general.

    Cheers, Al
     
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  15. pascs Jun 28, 2020

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    Great to see a fantastic 7A28 coming back to life. I've rebuilt a few 7A28 and thought they were quite decent to work on.

    A few of mine........

    4gGDPuz[1].jpg
     
  16. Willytfats Jul 12, 2023

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    Hi All, newbie here. Found this thread a couple years ago while researching an older Seiko Chrono, noticed, "I have one of these!", so started reading.... FASCINATING. Bought mine new, wore it a few years in the wrong profession, so I "put it up", and, frankly, forgot about it. Happened upon it while moving, and spent some "time" with it...after this thread, I gave up on any future research, but interest has resurfaced.....now wondering, which, if any, of you gents (or ladies) might like to take a crack at mine, or maybe steer me in the right direction? Thanx to all, in advance, for reading and pondering. I expect nothing, and am happy to read any help or responses. Thanx, Bill
     
  17. timjohn Jul 13, 2023

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    Depending on where you are you could try Adrian at Vintage Time Australia or Spencer Klein in the US. Not sure about who there is in Europe or elsewhere
     
  18. Pip Jul 13, 2023

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    There are a few of us dotted around who service them. I know a few in the UK (including me, I've done a dozen or more of them but don't have that much time), but let us know where you are and I can definitely recommend someone I'm sure. I'd probably not use SK these days as he has a very long waiting list.
     
  19. Archer Omega Qualified Watchmaker Jul 13, 2023

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    I think pretty much any watchmaker has a long waiting list these days - if they don't, then beware!

    You could try Ashton as well - he's done a lot of these...

    Vintage Swiss Watch Servicing, Repair, & Restoration | Precision Horology | Canada
     
  20. Pip Jul 13, 2023

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    Good point. Though I think SK is into 2 years plus wait last I heard. And yep, Ashton is good.
    There's a forum called seiko7A38.com run by a chap called Paul who is maybe the most knowledgeable chap there is on the 7a38 (same as 7a28 but with addition of day/date). I think on there he has a regional recommendation for people to work on these, might be worth a look.

    Edit: Not sure if you have to be a member to see it but here's a link (hope links to other forums are allowed, if not then apologies and mods please nuke it). https://seiko7a38.com/forum/viewtopic.php?f=17&t=67
     
    Edited Jul 13, 2023