Mechanical WW ETA 2783 - Minute/hour hands stop moving at 23:35 every day. Second hand continues.

Discussion in 'Watch Repair' started by SKULLY, Apr 27, 2015.

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  1. SKULLY

    SKULLY New Member

    Mar 22, 2014
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    Hello.

    This watch (70's Hamilton Auto) works fine until 23:35. The hour and minute hands stop moving, while the seconds continue to tick. I've had the dial off and watched everything working smoothly. The calendar wheel and it's click all work great when setting - either in set mode and quick-set for calendar.


    Today I removed the balance and pallet fork and again, everything was smooth when keeping some light pressure on the crown. (Hands never stopped.)


    However, under extremely light pressure, I can feel increased "drag" when hands get to about 23:20. That light drag continues until the date change at 00:00. After midnight the drag disappears and only super-light pressure is needed to make the hands move.


    I don't want to open it up again until I get some fresh ideas. Doesn't seem like your basic "cannon pinion requires tightening" issue. No missing teeth on any wheels.


    Thanks!
     
  2. Nedredbeard

    Nedredbeard Registered User

    Mar 7, 2015
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    Paradise ca
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    Re: ETA 2783 - Minute/hour hands stop moving at 23:35 every day. Second hand continu

    It's possible that the date wheel is warped or there is a bent tooth on the on the calendar. Also check to see that no screws are protruding and interfering with the calendar disc.
     
  3. doug sinclair

    doug sinclair Registered User

    Aug 27, 2000
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    Re: ETA 2783 - Minute/hour hands stop moving at 23:35 every day. Second hand continu

    It is possible that the minute pinion assembly (cannon pinion and its friction fit drive wheel) are slipping when the calendar trip wheel engages with the date ring. This assembly can be successfully tightened if you have a staking tool.
     
  4. SKULLY

    SKULLY New Member

    Mar 22, 2014
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    Re: ETA 2783 - Minute/hour hands stop moving at 23:35 every day. Second hand continu

    I'm always one to suspect something unfamiliar. I actually successfully re-fit the "friction fit drive wheel" to the base of the cannon pinion. (Prior to starting this thread.) Seemed like a relatively secure fit. I have access to a staking set. Would I just flatten the "leaves" at the center of the wheel and re-fit, or tighten while it's on the cannon pinion?

    Is this the connection that acts as "normal" cannon pinion would against center wheel pinion? (Limited slip for setting)


    Thanks!
     
  5. dAz57

    dAz57 Registered User

    Dec 7, 2011
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    Re: ETA 2783 - Minute/hour hands stop moving at 23:35 every day. Second hand continu

    Remove the canon pinion from the wheel, place the wheel on a flat stump, use a domed punch to slightly flatten the prongs, I find a domed punch helps to centre the wheel and give an even compression of the prongs.

    To fit the canon pinion back on, use a hole in the staking base that fits the tube on the bottom of the canon pinion, centre the wheel over this and with the canon pinion held in a hollow stake press the canon pinion back on, this is so you don't distort the prongs.

    Now test the canon pinion and wheel by holding the pinion in a pin vise and hold the wheel with your fingers and see how much friction or tension you get, if it's still loose tighten it again,
     
  6. SKULLY

    SKULLY New Member

    Mar 22, 2014
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    #6 SKULLY, Apr 29, 2015
    Last edited: Apr 29, 2015
    Re: ETA 2783 - Minute/hour hands stop moving at 23:35 every day. Second hand continu

    I continued testing last night. (No additional repairs)
    First test:
    Stopped at 23:28.
    I bumped the minute hand to 23:30 and everything continued through date change. I'd tried this before, and the hands would usually stop again prior to date change.

    Second test - I believe had similar result.

    Test 3-6 had NO stopping. I set it this morning and it's run perfectly through the date change.

    Fingers crossed. I wasn't looking forward to going into this again. Here's a picture of the Hamilton. Deserves better lighting. It has an earthy, green dial that for some reason has this even bubbling patina. (slightly less even since I pulled the hands.:() I like the goofy oval bezel, but I wouldn't own it if it weren't dirt cheap. Pretty clean, overall.
    IMG_4450.jpg IMG_4451.jpg IMG_4454.jpg

    I report back in a few days. Thanks!
     

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