Pendulum Question from a Newbie

CECat

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Sep 8, 2011
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Hello,

We have a grandfather clock with a Jauch movement, wooden stick and brass disc pendulum with two decorative nuts on threaded rod at the tip. It keeps time fairly well, but changes seasonally. We have accommodated that by making adjustments to the pendulum via raising/lowering the disc, usine the nuts on the threaded rod at the tip. However, we are now finding that we can't elongate the pendulum enough to slow it down adequately.

We took the pendulum to a clock repair shop in a distant city. The gentleman there did not believe that further elongation would solve the problem, but added a small piece of wood at the top of the stick. When we reinstalled it, the clock would not run at all. We then removed the added wood, put the pendulum back as it had been, and it ran the same as ever. What we had originally intended, rather than the addition of extra wood at top, was a replacement of the threaded rod at bottom with a slightly longer one.

So, my questions are these:

1. Is extending the threaded rod a reasonable solution? Is replacing the threaded rod with a longer one something that could be done by careful but inexperienced amateurs?

2. How far into the stick would a threaded rod normally be inserted? Is it possible that the current one could just be backed out a little?

3. If extending the rod is not a good plan, are there other methods to achieve the same end (slowing down the clock) -- preferably those that could be accomplished by careful amateurs, as we are far from any experts and are not anxious to ship any parts of the clock away and risk damage in transit.

Thanks very much!!
Susan
 

harold bain

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Hi, CeCat, welcome to the message board. Your clock is exhibiting the classic signs of a movement in need of service. They typically will gain time as the pendulum's arc declines. You could add weight to the bottom of the pendulum, to change it's center of gravity, which has the same effect as lengthening the rod, as a short term solution, but eventually you will have to have the movement either replaced with a new movement, or overhauled.
 

Scottie-TX

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What HAROLD wrote is probably the case. But to answer your pendulum question, it doesn't matter whether you lengthen the stick at the bottom or top doesn't matter. It SHOULD run either way. My suspicion is that something else was wrong when the clock wouldn't run on the extension - something you overlooked - something.
I thread the rod at least 3/4 to one inch into the stick.
 

shutterbug

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Mirroring what Harold said, altering a part that used to work but no longer does is just band-aiding the problem. How much additional length do you need? Maybe a longer suspension spring at the top end would suffice for now. But, the longer you put off the repair, the more complicated it could become, which in turn costs more to repair.
 

Tinker Dwight

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Oct 11, 2010
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Hi
To echo what others have said.
It is like driving on a flat tire.
If you stop right away, it is a simple
patch in the tire.
Keep driving it and then the ante is
increased to a new rim and a new tire.
As for the seasonal changes. Wood is
like that. It would be great if the clock
had its own climate control.
Tinker Dwight
 

Tom Groulx

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Jun 3, 2007
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Greetings,
The problem is the pendulum is most likely not swinging very wide. If you observe the pendulum swing from its far left to its far right position, I am willing to bet that it is between 1 and 2 inches from point to point. It should be around 4 inches. The reason the swing is so short is because the amount of power being delivered to the top of the pendulum is decreased. The reason this power is decreased is most likely caused by lack of lubrication, excessive dirt and excessive wear.

All three of these things can be corrected by a professional clock repair person. I do not believe the person you took the clock to falls into that above category. The reason I say this is because any legitimate experienced clock repair person would have added length to a pendulum to correct this problem.

To fix this clock it needs to be disassembled, cleaned and have bushings installed to correct for wear. If I do a job like this I give the customer a two year warranty.

Once you have this problem corrected, the pendulum will have a wider swing and since it will take longer to make that swing the clock will run slower and you will be happy.

What the previous posters said regarding the regulation changing between seasons is accurate especially with wood stick pendulums.

Good luck,

Tom
 

bangster

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Hi
To echo what others have said.
It is like driving on a flat tire.
If you stop right away, it is a simple
patch in the tire.
Keep driving it and then the ante is
increased to a new rim and a new tire.
As for the seasonal changes. Wood is
like that. It would be great if the clock
had its own climate control.
Tinker Dwight
I thought wood was used for pendulum sticks because it expands & contracts less with temperature changes than metal does. Did I hear wrong?
 

Jay Fortner

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Feb 5, 2011
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Hey Susan, If I read correctly you used the word "nuts" as plural. If your clock has two regulating nuts, the lower is for fine tuning and should not be run up against the top nut. I don't think this is your problem,as others have said it's due for service,just wanted you to know.
 

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