Seth Thomas Suggested pendulum weight range for mantle clock movement # 89 & 4 1/2

Discussion in 'General Clock Discussions' started by John Eckenrode, Apr 11, 2018.

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

    John Eckenrode Registered User

    Mar 3, 2018
    11
    0
    1
    Male
    Country Flag:
    Hello folks, I'm new to this game, and have a couple of seth Thomas movements, one numbered 89c and another numbered 4 1/2. I cleaned and oiled them. I'm noticing that they both run ok using a pendulum weighing 2.8 oz but run for a while and stop on pendulums weighing 4.6 and 5.2 oz. What are your thoughts on the best weight for these movements. Note, one 89c is pictured below.

    Also, a quick question - do the lantern pinions need to be oiled, or just the bushings on the front / back plates?

    Thanks folks!
    s-l275.jpg
     
  2. KyleG

    KyleG Registered User

    Nov 4, 2006
    84
    2
    8
    Country Flag:
    Region Flag:
    Most of the S/T clocks I own with 89 type movements came with 5-5.2 oz weights and run fine. Others with more experience may have other opinions.
     
    John Eckenrode likes this.
  3. Uhralt

    Uhralt Registered User
    NAWCC Member

    Sep 4, 2008
    3,703
    349
    83
    Country Flag:
    Region Flag:
    First of all, don't oil pinions. That would cause excessive wear due to abrasive dirt getting embedded in the oil. Oil the bushings. Your problem might be related to the fact that the clock may be slightly out of beat. A heavier pendulum causes more problems than a lighter one if the clock is out of beat because the heavier pendulum needs to be pushed "up the hill" on one side. The clock is in beat when you hear an even tick-tock.

    It is also possible that you have a power problem and maybe a bushing or more need to be replaced.

    Uhralt
     
    John Eckenrode likes this.
  4. Bruce Alexander

    Bruce Alexander Registered User
    Sponsor NAWCC Brass Member

    Feb 22, 2010
    5,837
    319
    83
    Male
    Retired, not tired
    Country Flag:
    Region Flag:
    Welcome to the NAWCC Message Board John.

    These are both 89 variants. As such, I believe that they should have deadbeat escapements. Having them in beat is very important as Uhrait notes. I've seen 89's running with the Seth Thomas "Boy on a Fence" Bobs in Sonora Chimes but I'm not certain they were original to the movement. Reportedly that Bob weighs 3.6 ounces and would probably be on the light side for these movements. I don't believe that a 2,8 ounce pendulum is "stock" for these movements.

    Here is a link for setting the beat: https://mb.nawcc.org/wiki/Beat-Setting-101

    When you have a few moments to spare, try to familiarize yourself with the permanent threads at the top of this forum or at the top of any forum. There you'll find a lot of very helpful Forum specific (or general) information at your fingertips.
     
    John Eckenrode likes this.
  5. shutterbug

    shutterbug Moderator
    NAWCC Member

    Oct 19, 2005
    40,293
    630
    113
    Male
    Self employed interpreter/clock repairer
    Iowa
    Country Flag:
    Region Flag:
    2.5 to 4 oz should do it. It's not a critical factor in the clock continuing to function. If it stops, it's likely another issue.
     
    John Eckenrode likes this.
  6. John Eckenrode

    John Eckenrode Registered User

    Mar 3, 2018
    11
    0
    1
    Male
    Country Flag:
    Thanks folks, all of you! I'm grateful for your help.
    John E
     
  7. Bruce Alexander

    Bruce Alexander Registered User
    Sponsor NAWCC Brass Member

    Feb 22, 2010
    5,837
    319
    83
    Male
    Retired, not tired
    Country Flag:
    Region Flag:
    You're welcome John. Regarding your question on oiling lantern pinions: Oiling a clock can really open a can of worms around here. With something so basic, you would assume it to all be a cut and dry subject. Believe me when I tell you that it isn't. I think all would (or should in my opinion) agree that you don't want to be squirt-n oil in them things. :)

    Here's a good reference from one of those permanent threads bangster has put together for us. Oil a clock, How To (5 pages) • I know that Uhrait already gave you good advice on the specifics of your question but if you get a few moments, look over bangster's thread on the subject. It may answer questions you haven't asked yet.

    Regards,

    Bruce
     

Share This Page