Seth Thomas bob weight?

Discussion in 'General Clock Discussions' started by MikeDeB, May 12, 2016.

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  1. MikeDeB

    MikeDeB Registered User
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    I recently overhauled this Seth Thomas and found that the bob is not original. The bob that is with the clock is a replacement and weighs just over 2 ounces. It runs ok but is a little erratic near the end of the spring wind. I tried one from a Seth Thomas 89 that weighed 5 ounces. The clock was very steady but too slow. I believe one in between these weight ranges will work. I know Timesavers and Merritts has them I just need to know which weight. I've included pictures of the clock and the movement. BTW, the movement pic was taken before it was overhauled.
    Thanks in advance!

    STAdamantine1.jpg STAdamantine2.jpg
     
  2. Bruce Alexander

    Bruce Alexander Registered User
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  3. lpbp

    lpbp Registered User
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    For this movement and clock you need the Timesavers #15850, this is out of an old catalog they may have changed the number, it's an adjustable cast bob, 1-1/8" 2.2 oz.. The boy on a fence is for the 89 movement.
     
  4. Bruce Alexander

    Bruce Alexander Registered User
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    Thanks Larry, that is good to know. The OP says the movement had a bob just over 2 ounces but it became a "little erratic" toward the end of the week. Not sure what that means. Perhaps Mike will clarify? It could be that the problem is not in the pendulum bob weight.

    Regards
     
  5. Willie X

    Willie X Registered User

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    Mike,
    You didn't identify the clock you are working on. Seth Thomas made many different movement models and each model usually had more than one type of pendulum. A picture would greatly narrow the field.
    Willie X
     
  6. Willie X

    Willie X Registered User

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    For some reason, your pictures just popped up. That is a shouldered movement, probably stamped 3 5/8, it preceded the 89 model. It came with at least 3 different pendulums. The 5 ounce lead bob with rating nut was probably the most common one and a good repo is readially available. Please report back on how the 5 ounce pendulum affects your clock's timekeeping.
    Good luck, Willie X
     
  7. lpbp

    lpbp Registered User
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    The reason I said that bob is, thats whats in the same clock that I own.
     
  8. MikeDeB

    MikeDeB Registered User
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    I was hoping someone with an original bob could weigh it and let me know. The attached pic is from dashley and I've tried getting a hold of him but to no avail.

    wIMG_1306.gif

    The above is picture of dashley's clock (it's the same as the one I worked on, just a year apart) shows what I believe to be an original bob.

    Larry, timesavers part no. 15850 is still available but I'd be putting in the same bob which is aftermarket. Seth Thomas bobs didn't look like 15850. They were thinner and wider like the above picture.

    Willie, I tried a 5 ounce weight in the clock from a Seth Thomas 89 movement and while very steady it was several minutes slow a day; too heavy for a shouldered movement.

    I appreciate all help so far.

    Thanks,
    Mike
     
  9. bruce linde

    bruce linde Technical Admin
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    there are currently 16 results on eBay for 'antique pendulum bob seth thomas'... with a couple of them looking like what you're looking for.

    there is a site i use called AUTOMATEDSEARCHES.COM where you can set up your search param and get an email every day with the results. the guy who runs it is both nice and responsive. i have searches set up for 'seth thomas regulator', 'e. howard', etc.

    of course i spend far too much time browsing the digital aisles for antique clocks and parts, but then i also tend to find what i'm looking for... as long as my clients think i'm working on their websites everyone is happy! :cool:

    best of luck in your search,
    smike
     
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  10. Willie X

    Willie X Registered User

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    Mike,
    As already stated, there is no one "original" style bob for this movement, there are several. The one in the picture is lead, no paint, weighs about 5 ounces, and has a little round ledge on the bottom which contacts the rating nut. These are available and adjustable, the most common of the bobs I have seen on the 3 5/8" ST. Bobs that came on 89s were not adjustable and painted gold, they relied on the rating adjuster in the movement. Dig?
    Willie X
     
  11. MikeDeB

    MikeDeB Registered User
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    Thanks Willie. I believe I know which one to go with now.
     
  12. Willie X

    Willie X Registered User

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    #12 Willie X, May 17, 2016
    Last edited: May 17, 2016
    Mike,
    Here is a photo of two original S-T pendulums taken from running 3 5/8" S-T clocks. The small one is what Ipbp mentioned and the larger one is in your last picture. These clocks also came with a small cylinder bob which is rare, AFAIK it was never reproduced. Willie X
     
  13. Willie X

    Willie X Registered User

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    Will try again.

    20150816_153836.jpg
     
  14. Bruce Alexander

    Bruce Alexander Registered User
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    #14 Bruce Alexander, May 18, 2016
    Last edited: May 18, 2016
    When I suggested the ST Boy on the Fence Bob, that was because it weighs in range you were originally looking for. I had to get into my "Way Back" machine but I found a ST No 44 "Hip" Movement that I worked on which had what I believe was the original Bob. It was the larger unpainted/unfinished adjustable bob that Willie has referred to. The Bob had a long range of adjustment and worked well in the movement. If this kind of bob is not working with the movement you cite, and the lighter bob also doesn't work, perhaps something else should be examined/ruled out. You could always try the Boy On A Fence 3.6 ounce Bob to see if it makes a difference, but it's not adjustable and evidently is not really appropriate for this movement. If you can get the movement properly rated with the 3.6 ounce Bob you could at least see if it makes a difference over the 8-day cycle. Good luck.

    Arno Testing.jpg
     
  15. Yuri

    Yuri Registered User
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    Hello everyone. I have a Seth Thomas model 89 movement without pendulum bob, and was going to buy one that weigh about 5oz, but now I'm confused by this thread. Does anybody know for sure what bob was used for this particular movement?

    image%3A322052.jpg
     
  16. Willie X

    Willie X Registered User

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    There were several bob's that were supplied with this movement directly from the factory. The most common one was 5.2 ounces that has a brass cap on one side. A similar one is available as a repoduction. Here is a photo of an original bob from #89 S-T.
    Willie X
    20180827_190721.jpg
     
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  17. Yuri

    Yuri Registered User
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    Thank you.
     

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