The Mechanical Clock Pendulum Assembly
The Mechanical Clock Pendulum Assembly
The mechanical clock pendulum assembly does not mean just the pendulum alone.
The use of the word assembly means the pendulum consists of three components and not just the pendulum. A pendulum assembly consists of the suspension spring at the top, the leader that hangs on it, and then the pendulum.
Pendulum styles
Usually mechanical clock pendulum makers are not movement makers and the two are married together by a person or place. A place such as Clockworks or Howard Miller instead of the movement manufacturer. This is interesting because it explains why there can be so many variations in pendulums for one movement.
The pendulum could be a brass rod, wood stick, or metal lyre style.
Pendulum bob diameter size
To determine the bob diameter for a mechanical clock pendulum, need to consider what looks good as well as which one won't whack the sides of the case. A good rule for the bob diameter is it needs two inches on each side to swing.
So if the clock case is 12 inches wide the bob cannot be more than 10 inches. In this example we would need a 10 inch bob but these are not made.
So the choice is clear that for a 12 inch wide clock case the maximum bob size to get is 8 1/2 inches wide. If this rule did not exist and the 10 inch wide bob is run the clock may go tick, knock, tock, knock, as it hits the sides every time it swings. Eventually the clock will stop running from this resistance. Plus it is quite annoying to hear that sound!
Pendulum lengths for Mechanical Clock Pendulum Assembly
The length of the pendulum has to be correct for the gearing inside the movement. If the mechanical clock pendulum is too long the clock will be too slow. If the pendulum is too short the clock will run too fast. When a clock is too fast or slow it usually has nothing to do with the movement itself. It only has to do with the pendulum length alone and nothing else.
Pendulum top mount hook
The top hook has to hook to the leader on the movement. The leader is the part that holds the mechanical clock pendulum up in the air and it hooks to the suspension spring. Sometimes an old pendulum will not hook to the new movement the same way as it did on the old unit. However, this is not common. It may or may not need a new top hook for the pendulum.
Pendulum leader
The leader is the 3 to 7 inch long part that the mechanical clock pendulum hangs onto. The leader hangs onto the suspension spring which is on top of the movement. At the same time it will have the crutch on the back of the movement engaged with the center of the leader. The crutch is the wig wag part that is sticking out of the back of the movement.
To install the leader, remove the set screw on top of the suspension spring. With the suspension free it can hook onto the leader and be brought back up. The leader then goes onto the suspension and the crutch on the back of the movement at the same time. This assembly gets brought back up again to mount with the set screw like it was.
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When replacing a pendulum in a mantle clock, does the hook face forward or backward when attaching to adjustment spring? I removed my pendulum for adjustment and then got confused when replacing it. Thanks for any assistance or advice.
Either way works, no one sees it but you.
But on mantles, usually the pretty side of the bob points to the back, while the hook on it hooks forward.
James Stoudenmire
30yr Clockmaker
Author of Clockworks.com
Does it matter which way round i hang the pendulum
Sometimes it does only, like if it is a Kieninger unit the leader cant be the wrong way. Usually does not matter.
James Stoudenmire
30yr Clockmaker
Author of Clockworks.com
I took my pendulum off and I believe the leader came with it. I have an old regulator wall clock. I am unsure of how to attach this leader part to the suspension spring as described in your tutorial. I would appreciate any help thanks
Best to ask this questions with pics emailed to clockworks@clockworks.com
James Stoudenmire
30yr Clockmaker
Author of Clockworks.com
I took my pendulum off my Regulator wall clock and with it came about a four inch piece with a loop at one end and the other end flattens out then narrows a touch and then widens again. On my mechanism I have about the same length piece that attaches to a piece that interacts with the gears. Its end is a small oval loop and my guess is it attaches to it but don’t know how. Any help is appreciated
I would need to see some pics
Clockworks@clockworks.com
James Stoudenmire
30yr Clockmaker
Author of Clockworks.com
My old clock from the 1890s runs fast. I have the bottom nut screwed down as far as it goes with out it falling off. The clock still runs fast is there something else I need to do to slow it down. This clock is an old shelf clock.
Hi,
What are the numbers off of the back plate of the clock movement itself? If it is hard to get to, usually you can stick a cell phone up behind the movement and get a picture of the numbers. Or through the side access panel if there is one.
James Stoudenmire
30yr Clockmaker
Author of Clockworks.com
I just inherited a ST floor model with movement A451-002. When moving the pendulum leader fell off. Its a LEAD-H leader. I installed it with that little attached bracket facing toward the end of the shaft, as it seemed to mate up there. Is that correct, or should that bracket be toward the gear mechanism? Photo attached. I wish I could be more clear, but it’s my first look into one of these things. Thanks so much in advance for anything you can offer.
On that unit, the hook faces the back of the wood case and not the back of the movement.
It is reversed in the pic
James Stoudenmire
30yr Clockmaker
Author of Clockworks.com
Sorry this will sound so dumb but I can not see how to hook up the pendulum on my grandfather click . my great aunt came home with it in the 50 after she was in Germany. Its never been moved since then and when my cousin passed away a few months ago I brought it to my home . I was careful as if it was a newborn baby but as I pulled the head of the click from the padded box I made to move it , the piece between the gear and the pendulam iitself fell off and I don’t remember how it hooked on. Any help would be great .
What are the numbers off of the back plate of the movement itself? Maybe you can use a cell phone to take a pic of the back of the movement, so you can get these numbers. This way I can show you the exact parts that are involved.
James Stoudenmire
30yr Clockmaker
Author of Clockworks.com
How does a bob attach to a wood pendulum?
Should just slide on the wood stick.
See this link for help: https://www.clockworks.com/posts/clock-pendulum-stick-assembly
Thank you !
Hi
See this link on how to assemble a wood stick pendulum and bob = https://www.clockworks.com/posts/clock-pendulum-stick-assembly
James
Thank you !
we have a over 100 year old clock that needs service…i have been able to make it keep correct time but the gong only gongs once on the hour…. but when i was setting it it gonged once for every hour ex 10 gong,gong s at 10 oclock
I live in southwest OK and am looking for someone who is trained on such clocks pendulum and weighted movement.
our clock goes bong bong in two tones beautiful deep tones is a floor standing two bongs at one o clock a d 12 bong bongs at 12 oclock
There is a clock shop attached to wagon wheel restaurant in Ulysses, ks. A little old Mennonite man runs it. They have worked on several of our antique clocks/pocket watches and all are in great working condition now.
Sounds fun!
James Stoudenmire
30yr Clockmaker
Author of Clockworks.com
How dow the 3little nuts go on the bottom of my barwick clock #C10628
which 3 little nuts are you speaking of? pics would help us understand.–Bob
My pendulum will not swing any more.
Hi
We would need the movement numbers off of the movement itself please
Like this =