Why clock started running fast

Discussion in 'Clock Repair' started by Ron Roberts, Jan 13, 2020.

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  1. Ron Roberts

    Ron Roberts Registered User
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    May 14, 2019
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    My wife inherited a grandfather clock from her mother. It has run well for many years, but in recent months it has been running fast. I have let the pendulum down as far as it will go and the clock still runs fast. Attached are pictures. It is a Howard Miller and was procured in about 1986.
    I disassembled, cleaned, oiled and reassembled the movement and could not see any issues.
    Can anyone tell me why the clock might be running fast?

    movement.jpg pendulum.jpg
     
  2. shutterbug

    shutterbug Moderator
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    Oct 19, 2005
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    My first instinct is that it's skipping teeth. Perhaps the verge needs to be adjusted lower? If it is skipping occasionally, it could damage the teeth of the escape wheel. Usually a pendulum clock can't really just start to gain time unless something like this is occurring.
    The only other thing I can think of is something might be slipping in the motion works. Does the minute hand move easily enough that it could be slipping? Or the collet in the hand might be loose?

    This might do better over in the repair forum. I'll move it for you.
     
  3. Ron Roberts

    Ron Roberts Registered User
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    May 14, 2019
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    The part that holds the verge does not allow up or down adjustment as some clocks do. There are no missing teeth on any of the time gears. The minute hand has good friction and is not slipping. This is one of the strangest things I have seen having works on hundreds of clocks.
    I agree, a pendulum clock can't just start running faster absent the pendulum length being adjusted, but this one did.
    The only thing I can think of is to add weight to the lower part of the pendulum so as to lower the center of gravity and thus the effective pendulum length.
     
  4. R. Croswell

    R. Croswell Registered User

    Apr 4, 2006
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    You should not need to add weight or change any part of the pendulum if the clock kept time before. Just how much time does it gain in 24 hrs.? Make sure that no part of the pendulum or the crutch or anything that moves with the pendulum is bumping into a swing limit post or stop or any part of the case. I'm sure you are not missing any teeth on the escape wheel, but you may have a single tooth that has the tip bent or one that is a but shorter that occasionally "skips". Can we see a picture of the back side of the movement, and a picture of the escapement? When you had it apart did you install any bushings?

    RC
     
  5. Willie X

    Willie X Registered User

    Feb 9, 2008
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    If you took the pendulum post off, you could have replaced it to high. Take off the pendulum, loosen the two screws slightly, push it down and retighten. There actually is a small amount of adjustment here.

    The autobeat mechanism could be bad, too loose but this is unusual. I would say that the most likely culprit is moderate wear at the escape wheel pivots. This gives the symptom Bugs just mentioned. The e-wheel teeth are landing shy of the right place on the pallets. The teeth should go deep enough to always land on the upper 'dead' faces, NOT the slanted 'impulse' faces at the pallets tip.

    WIllie X
     
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  6. Dick Feldman

    Dick Feldman Registered User

    Sep 1, 2000
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    The escape wheel in your clock is moving faster than design.
    This may be an oversimplification of the symptom but anything that may cause the escape wheel to move too fast can be a culprit.
    Like the other posters, I would look first at the relationship between the escape wheel and the verge as that is what regulates the speed of the clock hands.
    Certain movements are well known to wear the escape wheel teeth to the point that the verge will skip over teeth occasionally. This is inconsistent and the gain will not be the same over any set period.
    Have you watched the escapement operate for a few minutes? Sometimes one can see the skip.
    If you have a Time Trax or Microset timer, there are ways to detect the number of beats/hour.
    Best,
    Dick
     
  7. Peter John

    Peter John Registered User
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    Sep 4, 2018
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    1986-2020=34 years. Most likely an urgos auto beat movement. The escape wheel teeth are probably worn off. First clue is running fast. Second is a very narrow pend swing. You need a new escape wheel. Also the chime trip lever is turned 90 degrees too far counterclockwise Peter
     
  8. Willie X

    Willie X Registered User

    Feb 9, 2008
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    Ron,
    Look up "Urgos UW03 running as a recoil" or just " deadbeat running as a recoil". This fault has been covered many times. You may have to change the search words around a bit. Willie X
     
  9. Ron Roberts

    Ron Roberts Registered User
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    May 14, 2019
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    All thanks for your replies. Based on the comments I would guess the problem is an escape gear that is worn, since the clock worked well for many years. I will research, but does anyone know if a replacement escape gear can be ordered??
     
  10. 0ldMan

    0ldMan Registered User

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    As I get older (only 73 now), I realize they aren’t making as much time as they used to. Clocks usually don’t show that, but maybe yours is special ?
     
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  11. Willie X

    Willie X Registered User

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    Usually, you can elongate one of the holes on the pendulum hanger bracket to give you a little more adjustment, or replace the e-wheel and/or rebush the
    e-wheel pivots, if necessary. Mark Butterworth had a supply of unmounted e-wheels (?) not too long ago. It's a routine job. WIllie X
     
  12. Ron Roberts

    Ron Roberts Registered User
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    May 14, 2019
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    I spoke with a long time gear maker that I have used many times who recommended Butterworth. I called them, they claim they have a new gear that I will have to mount on the shaft.
    It should be here in a few days and I will let all know if it works out.
    Thanks again for all the replies.
     
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  13. Ron Roberts

    Ron Roberts Registered User
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    May 14, 2019
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    So I did order a new replacement gear from Butterworth and installed it. The clock is working just fine now. Thanks for the idea.
     

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