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Speedmaster moon watch accuracy and winding

  1. rollee Oct 28, 2016

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    I have been timing my (2012) 3570.50 daily the past 18 months, and I discovered an odd behaviour on its accuracy. Base on time.is

    When the watch is fully wound to 100%, it runs -7s / 24 hours. If wound only up to 75% full, it runs 0 accurate right on, no matter normal wearing or stored face up, deviation is about 0.5s, which is phenomenal.

    Power reserve is 51 hours, I counted the turns of winding to estimate its power reserve.
    Amplitude is over 300 which is very healthy.

    Has any member here experience this?
    Should I have this watch serviced or to leave it alone?
    Might I do any premature wear and tear by not winding up to the end?
     
  2. repoman Oct 28, 2016

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    Have you considered buying quartz? :D
     
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  3. Archer Omega Qualified Watchmaker Oct 28, 2016

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    Omega timing specs for the Cal. 1861/1863 movement are from -1 to +11 seconds per day for average daily rate. If your watch is running at -7 seconds per day when fully wound is it out of spec certainly. State of wind and position will affect timekeeping certainly, but without properly taken timing machine readings, it's difficult to say what may or may not be wrong with your watch...

    The watch is designed to be fully wound once per day...

    Cheers, Al
     
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  4. padders Oooo subtitles! Oct 28, 2016

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    One of my Speedies, a 3570 was serviced by STS recently because I noticed that it was running way fast when fully wound. It took them a couple of goes to regulate it properly but it too was showing very different timing machine results with different main spring power which I thought very odd since no other piece has done that in my care so yes I have seen something like it before.
     
  5. Archer Omega Qualified Watchmaker Oct 28, 2016

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    Was this after service that it would run very fast when fully wound? If so, it's not a regulation issue...the watch was rebanking, which is not uncommon at all with 1861's after a fresh service. This is a completely different situation to the OP's.

    Cheers, Al
     
  6. padders Oooo subtitles! Oct 28, 2016

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    The variable rate was happening before the service and was very noticeable using the timing machine. The issue after the service was primarily that it ran very fast, I didn't really test it to see if it varied, just sent it back, twice! I agree that there could have been a different issue here and from my limited knowledge of watchmaking, your explanation does make sense. Too much amplitude caused by a over strong main spring?
     
  7. Archer Omega Qualified Watchmaker Oct 28, 2016

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    Well, you haven't given enough detail to say for sure if that's what it was. Like what does "very fast" mean in real numbers...

    When viewed on a timing machine, rebanking will show as very high amplitudes, and what amplitude is "safe" from rebanking depends on the geometry of the escapement and pallet fork horns. If it is pushing in the high 330's in a horizontal position (lift angle set correctly of course) then you risk rebanking on an 1861. You will then see the daily rate jump from whatever it is to +800 or +900 seconds per day for the time period the watch is rebanking.

    The cause is too high of an amplitude, and that can be from several reasons depending on the watch. Too strong of a mainspring, too little lock on the escapement, improper train lubrication (too light of oil used), or in an automatic, too much braking grease. One way of diagnosing what the cause is relates to how long it rebanks for - if it's a very short period of time it's more likely a lubrication problem, but if it rebanks for hours (some can in extreme cases) then the mainspring is likely too strong - just some examples of how I personally troubleshoot this problem. But many things need to be looked at, and this is not a "tweak the regulator" to fix it kind of problem. Sometimes you go deep down the rabbit hole trying to chase a solution...

    Cheers, Al
     
  8. padders Oooo subtitles! Oct 28, 2016

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    The 'very fast' was about +100spd before the service when the rate varied and +40spd after, interestingly the amplitude never seemed to get above about 300deg after so it wasn't obvious what the issue was. As you say it is probably best not to worry too much on this issue since it is now fixed but it did rather shake my faith in the 1861 when the watch ran badly for the best part of 4 months until it was fixed. I do appreciate your efforts to explain it however.
     
    Edited Oct 28, 2016
  9. rollee Oct 28, 2016

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    I appreciate your replying. The reason to its accuracy behaviour can be anyone's guess without investigating the movement itself.

    This watch is fairly new, worn on rotation and I am expecting better accuracy. Perhaps I'll simply use it as is until its accuracy runs out for a full service.

    My concern is if continuously using an unfully wound watch can cause any premature wear to the movement.
    Al is there a way for me to find a timing machine to test exactly how much off spec it is, can I bring it to you?

    Btw, in the past 48 hours it lost 0.75 seconds.
     
  10. alam Oct 28, 2016

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    ::confused2:: your watch appears to be within the tolerance Al has stated...

     
  11. rollee Oct 28, 2016

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    Hi alam, my question is about the state of the watch on full power reserve, running out of spec by -7s/24 hours, while very accurate (from my previous post) when the watch is not fully wound up. Thanks.