Anniversary Clock Question

Discussion in '400-Day & Atmos' started by wbranko, Nov 13, 2018.

  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  1. wbranko

    wbranko Registered User
    NAWCC Member

    Feb 1, 2004
    388
    1
    18
    Male
    Country Flag:
    20181113_101921.jpg I am working on a Kundo 55 anniversary clock that recently stopped after working for 15 years. Since I am cleaning the movement and replacing the mainspring, I also wanted to fix a problem that has been there for a long time.

    Check out the enclosed photo.

    420893-7c66a489bda4b8cb4035092f4e812f1d.jpg


    I have checked the suspension carefully against the Horolovar diagrams in their book. It is completely within specifications...but notice in the photo that the pendulum hangs 4mm below the proper locking point for the unit. I could easily raise the bottom block 4mm, but obviously this will change the time. Can I do this and then adjust the pendulum to account for the difference?

    I also noticed that the area in the pendulum where the bottom block hangs looks egg-shaped. Is that normal, or has there been wear here that allowed the pendulum to drop?

    Thanks for your help in advance!!!
     
  2. Willie X

    Willie X Registered User

    Feb 9, 2008
    11,990
    692
    113
    Check for missing collars at the top and bottom of the support collums. The so called "specifications" don't always apply to all clocks. Shortening the spring or adding washers to increase the height of the colums would seem to be your only options.

    You would probably still have adequate adjustment to slow the rate with a 4mm reduction in spring length. If not, it's easy to 'thin' the spring using a small folded square of 400 grit wet and dry paper. Make light strokes while pinching the spring between the folded sandpaper. I use long downward strokes only while pulling gently downward on the pendulum ball assembly. It usually helps to swing the pendulum out of its guard at the base and to the back about 1 inch.

    Good luck, WIllie X
     
  3. KurtinSA

    KurtinSA Registered User
    NAWCC Member

    Nov 24, 2014
    3,224
    99
    48
    Aerospace Engineer (Ret.)
    San Antonio, TX
    Country Flag:
    Region Flag:
    To my eye, nothing looks wrong with the way the pendulum hangs. Actually, it has a very limited location for its position. Too high and the top collar of the pendulum interferes with the bottom plate; too low and the pendulum drags in the cup. You want the pendulum to hang down like that. When you need to lock it, you simply raise it up and engage the lock.

    Kurt
     
  4. mjstewart

    mjstewart Registered User
    NAWCC Member

    Feb 20, 2016
    31
    6
    8
    Male
    Country Flag:
    You will notice in your picture that there is a spring and collar below your bottom block and pin. If you lift up that collar (and compress the spring) you can then replace the bottom block pin so that it rests underneath the collar. This should clear up your 4mm difference. It takes some practice to find the right tool to catch the bottom of the collar and lift it up above the bottom block while maneuvering the pin with tweezers. I like to lie the clock on it's side and lock the pendulum in to do this.
     
  5. etmb61

    etmb61 Registered User
    NAWCC Member

    Oct 25, 2010
    2,284
    101
    63
    Retired Avionics Technician
    Mascoutah, IL
    Country Flag:
    Region Flag:
    Like this:

    Suspension spring length

    Eric
     
  6. KurtinSA

    KurtinSA Registered User
    NAWCC Member

    Nov 24, 2014
    3,224
    99
    48
    Aerospace Engineer (Ret.)
    San Antonio, TX
    Country Flag:
    Region Flag:
    Good eye, mjstewart!

    Kurt
     
  7. Willie X

    Willie X Registered User

    Feb 9, 2008
    11,990
    692
    113
    Wb,

    Kurt is on to something. You have the lower block pinned in the wrong position.
    It needs to be unpined and threaded all the way down to the rate adjustment disk. Then, you pick up that little hat shaped washer being held down by the spring. With the hat shaped washer in the raised position, you insert the pin through the bottom block and the hat shaped washer will can be released against the pin. Everything should lock into place.

    Note, this cross pin has to be the correct diameter and length in order to work. Something like a straighy piece of wire 1mm x 10mm, no taper.

    I can send you a photo, if you like. I have a couple of these being tested at present.

    Willie X
     
  8. Harry Hopkins

    Harry Hopkins Registered User
    NAWCC Member

    Nov 16, 2011
    543
    37
    28
    Retired Instrument Technician
    Mason, IL
    Country Flag:
    Region Flag:
    When installing the pendulum the cupped piece should be raised against the spring until the spring is all the way compressed. Sometimes you will need to push the bottom block down so the hole for the pin is exposed then insert the pin and then you can lower the cup shaped piece. I have had good luck raising the cup shaped piece with a pair of tweezers in one hand so the pin can be removed or inserted with a pair of needle nose pliers in the other hand and I agree that you do not want a tight fitting pin or a taper pin.. it is much easier to do if the pin is a slip fit instead of a snug fit. The cupped piece will hold the pin in place when everything is assembled correctly.
    image000000kp.jpg
     
  9. KurtinSA

    KurtinSA Registered User
    NAWCC Member

    Nov 24, 2014
    3,224
    99
    48
    Aerospace Engineer (Ret.)
    San Antonio, TX
    Country Flag:
    Region Flag:
    As I understand things, the pin was made to have a snug (sometimes a bit more than that) so the pin didn't dislodge during shipping, allowing the pendulum to crash about and destroy the glass dome. Whenever I encounter these clocks, I try and file down the knurling on the pin a bit so the fit is not so snug but not enough so that it falls out on its own. That way, the chances to muck things up when trying to take the pendulum off the suspension spring are reduced.

    Kurt
     
  10. MartinM

    MartinM Registered User

    Jun 24, 2011
    2,995
    86
    48
    Male
    Medical Insurance Systems Analyst
    El Dorado, CA
    Country Flag:
    Region Flag:
    Jusr removing and replacing the knurled pin a few times is usually enough to make it a good fit and not subject to circus acrobat tactics to get the pin to be where it's supposed to be.
    The ideal position for length of this assembly is to have the pendulum in the locked position and the spring is held taught by the coil spring on the pendulum.
    You should be able to deflect the center point of the suspension spring about 3/8 of an inch from centerline with the pendulum locked before the slack of the coil spring is taken up.
     
  11. wbranko

    wbranko Registered User
    NAWCC Member

    Feb 1, 2004
    388
    1
    18
    Male
    Country Flag:
    Just got back from a trip. Thanks to all for replying. The parts I need just came in from Merritts today, so I will probably work with this clock this weekend.

    The hanging arrangement I showed in the photo was a "quick shot" of the pendulum after I had taken it apart once, and then put it back together quickly just to show the height. The pin does need to be thinned. Since it is still very tight in the hole, I just pushed it in part way to show the hanging height. Glad I did, because I learned a lot from the posts. I will try to digest all of this and get it back together soon.

    Thanks again to all!!!
     

Share This Page