didn't realise you had to wind so often.

Thread: didn't realise you had to wind so often.

Results 1 to 10 of 10
  1. #1
    Member
    Join Date
    Feb 2010
    Location
    Shanghai
    Posts
    1,488

    didn't realise you had to wind so often.

    A while ago i thought there was something wrong with a longines manual wind watch i had since i wound it up and left it for 24 hours to discover it was off by over a minute, wich surprised me since it was a quality watch the movement appeared to be in great shape and i had been told it had been serviced less than a year ago when i bought it.

    I had been reading that people on the board wound their watches twice a day and got great results, so i wound it up put it back in the box and checked 12 hours later it was 2 seconds slow so i did it again and 12 hrs later about 2 seconds slower. i was really quite stunned 4 seconds a day on a 50+ year old watch on a watch beating at only 2/3 the speed of a modern movement, they really knew what they were doing back then.

  2. #2
    Member Eeeb's Avatar
    Join Date
    Jul 2007
    Location
    Great Lakes - USofA
    Posts
    18,156

    Re: didn't realise you had to wind so often.

    Mechanical watch design improvements in the last 50 years have largely been just tweaks on the old designs. Longines movements seem to hold up better than most others. I love 'em.

    The ability to keep the same rate, no matter what the state of wind, is called isochronism. It is more important in winders than in automatics. I typically see a 20 spd rate change as the watch winds down. Some are better than others. Some speed up. Some slow down. On this aspect new watches are usually better than old watches. ETA 2892-A2s show very little variation.
    "Forever is composed of nows." - Emily Dickinson

    "The watch has to be surrounded by a history.
    You need more than just a great design. You need to create an atmosphere around the product.
    Who is the company behind it? Why are they using this material?
    People need to be able to identify the watch with themselves. It's based on emotion." - Ralph Furter

    ...that's just my opinion and I've been wrong before and will be again and might be now!

  3. #3
    Banned
    Join Date
    Oct 2008
    Location
    NJ / Philly
    Posts
    7,645

    Re: didn't realise you had to wind so often.

    I bet with a new mainspring it would keep even better time. The mainspring was the weak point of most vintage watches, often becoming tired or outright breaking, and was the largest cause for a watch needing repair.

  4. Remove Advertisements
    WatchUSeek.com
    Advertisements
     

  5. #4
    Member
    Join Date
    Jun 2007
    Location
    Southampton UK as prisoner of work but home is a village in La Mayenne.
    Posts
    770

    Re: didn't realise you had to wind so often.

    Off by over a minute in 24 hours but fine if you wind twice a day. Not Longines behaviour at all. This watch needs a new mainspring by the sound of it as the old one appears to be weak. My own old Longines are over 50 years old and run to less than 5s/d, wound daily. I would expect nothing less as these were widely considered to be the best movements available at that time.

  6. #5
    Banned
    Join Date
    Apr 2007
    Location
    Middle of Hurricane Alley
    Posts
    21,244

    Re: didn't realise you had to wind so often.

    You state that the seller told you the watch was serviced about a year ago.
    Maybe.
    Maybe not.

    I would personally have it properkly serviced.
    It should not have that bad acuurancy after just 24 hours.

  7. #6
    Member AbslomRob's Avatar
    Join Date
    Jun 2009
    Location
    Ottawa, Ontario, Canada, Canada
    Posts
    5,315

    Re: didn't realise you had to wind so often.

    Just want to clarify a bit on that term. These are my own words (and are formed from my current understanding), so feel free to take issue if I've misrepresetned anything.

    Isochronism (as applied to a watch) actually refers to the ability of the balance wheel to maintain the same period of vibration regardless of the amplitude of its swing. The concept is extended from the theoretical properties of a pendulum, in which the amount of time it takes for it to make a full swing is independent of the how far it is swinging.

    I say "theoretical" becuase in the real world there are other physical properties that come into play. This is even more true of the balance wheel, because the period of the rotation is controlled by a spring, not gravity. The problem with springs is that the amount of energy they'll store and release varies with the amount of load already on them. The energy is really only applied to the end of the spring, and gets transmitted along the length of the spring from there. Because of the properites of the metal, you lose energy above and below a certain threshold. Therefore, a watch can only achieve isochronism so long as the power being applied to the balance wheel is within a certain upper and lower limit. Advances in hairspring material give modern hairsprings a fairly wide tolerance, and advances in mainpsprings have smoothed out the power curve from the mainspring, but even advanced materials get old, and as they do, the tolerances drop.

    In this case, I'm guessing the power from the impulse is dropping below that threshold after about 12 hours...indicating either friction in the train (dirt, lack of or excessive lubrication, excessive endshake, etc), low power from the mainspring (old "set" mainspring or mainspring out of true), or defective lever function (bent lever or misadjusted banking pins).
    My growing collection of "affordable" vintages: http://www.abslomrob.com

  8. #7
    Member
    Join Date
    Feb 2010
    Location
    Shanghai
    Posts
    1,488

    Re: didn't realise you had to wind so often.

    thanks for all the feedback. i appreciate all the new info i learn from everyone's posts. i guess off to a watch repairman after the may holiday.

  9. #8
    Member Eeeb's Avatar
    Join Date
    Jul 2007
    Location
    Great Lakes - USofA
    Posts
    18,156

    Re: didn't realise you had to wind so often.

    That definition is a variation of the same thing. The amplitude of the swing is directly correlated to the state of wind of the mainspring.

    It is interesting how people who actually get into watches (I rarely do) zero into the operational problems better than I. Learning is fun!
    "Forever is composed of nows." - Emily Dickinson

    "The watch has to be surrounded by a history.
    You need more than just a great design. You need to create an atmosphere around the product.
    Who is the company behind it? Why are they using this material?
    People need to be able to identify the watch with themselves. It's based on emotion." - Ralph Furter

    ...that's just my opinion and I've been wrong before and will be again and might be now!

  10. #9
    Banned
    Join Date
    Oct 2008
    Location
    NJ / Philly
    Posts
    7,645

    Re: didn't realise you had to wind so often.

    Quote Originally Posted by Eeeb View Post
    The amplitude of the swing is directly correlated to the state of wind of the mainspring.
    Correct - the more wound the mainspring is, the more stored energy it has and therefore the more push it gives to the impulse jewel. Rob is right though - whether the balance wheel rotates 320˚ or 210˚ it should take the same amount of time to complete one rotation due to momentum and elasticity of the hairspring. It is also possible that poor transmission of power from a good mainspring is being lost because of friction / resistance somewhere along the way. Odds are it's a weak mainspring though.

  11. #10
    Member Eeeb's Avatar
    Join Date
    Jul 2007
    Location
    Great Lakes - USofA
    Posts
    18,156

    Re: didn't realise you had to wind so often.

    Quote Originally Posted by ulackfocus View Post
    ...- whether the balance wheel rotates 320˚ or 210˚ it should take the same amount of time to complete one rotation due to momentum and elasticity of the hairspring...
    Indeed! To the extent it does that it exhibits good isochronism
    "Forever is composed of nows." - Emily Dickinson

    "The watch has to be surrounded by a history.
    You need more than just a great design. You need to create an atmosphere around the product.
    Who is the company behind it? Why are they using this material?
    People need to be able to identify the watch with themselves. It's based on emotion." - Ralph Furter

    ...that's just my opinion and I've been wrong before and will be again and might be now!

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •