How to Regulate the Time of Your Pendulum Clock?

There are two methods of adjusting the time regulation on your pendulum clock

1. Adjustment nut on the pendulum, if your clock has a small nut on the bottom or another place on of the pendulum, then use this method. 

To adjust the regulation, the pendulum rating nut must be turned, and the amount depends on how much time the clock is in error. If your clock is off less than five minutes a week, you may only need to turn the nut a revolution or less. If the clock is off more, you may need to turn it more. To accurately adjust the clock, make the adjustments once a week when the clock is wound. If you do this and keep a record of how much it is turned each week, you should be able to adjust the clock’s accuracy to within a minute or two a week. Use the following rules to adjust the PENDULUM NUT; 

If the clock is running slow, turn the pendulum nut clockwise to increase the rate. 
If the clock is running fast, turn the pendulum nut counterclockwise to decrease the rate.

2. Adjustment on the dial, if your clock has a small arbor protruding the dial near the “12” or the “6” or perhaps in the center of the dial, then use this method. You will need smaller key to turn the rating arbor. 

Some clocks will have a “S or F” by this arbor. For a ‘S-F’ mark, turn the arbor clockwise for faster and counter-clockwise for a slower rate. With a ‘F-S’ marking, adjust the arbor opposite as stated above. If there are no ‘S or F’ markings near the arbor, then use the trial and error method to determine the correction direction to make the time adjustment. Some times this adjustment can be turned too far; so do not force the adjustment if it tightens.


7 Responses so far.

  1. chris says:

    I have a German cuckoo clock ( do not have a specific name I can find anywhere) but this particular one has a wooden wedged pendulum that slides to adjust, with no markings on the stem as to time it, wondering how to adjust it to make it stay in sync, thanks for any help



  3. Azzhole says:

    You know . You write whole story but did not specify whether increasing or decreasing pendulum length will have run fast or run slow effect.

  4. Jim says:

    My pendulum is fixed. It has a nut beneath it but adjusting it up or down does not affect the pendulum. It simply will not move. It appears to have been made so it is deliberately fixed in place. Clock runs very fast despite nut now at bottom of rod. Will send photos if you are interested

  5. Jerald Johnson says:

    My antique kitchen clock strikes the next hour fifteen minutes early (when the minute hand is at the 9). How can I correct this so it will strike at the appropriate hour? Thank you. Jerry

  6. Tim Little says:

    Hello: I have purchased a Morbier clock for around 1870. Once I got it set up it gains about 30 minutes a week. If I let the thumb screw out more the “bob” falls below the lyre pendulum rod, making it unstable or askew. It also makes a loud drop sound when it goes to strike the hour and then again in 5 minutes when it strikes a second time as are customary to this type of clock. If you are familliar with this type of clock, is that drop sound normal? This is the first of these kinds of clocks that I have owned, I have several pendulum clocks, Seth Thomas regulators mostly and a french Verdette. In regards to the Morbier, do you think that I should take it in for service or is there something that I can do to service it my self. It came through a reputable dealer in Amsterdam Holland. So returning to him would not be the best choice. I do have a great clock man here in Oakland California but I don’t want to be over reacting if its something I can fix or live with as just a function of the clock. What do you say? Thanks in advance for taking my question.

  7. Seth Kuhn says:

    I have pendulum clock, runs 10 minutes slow a day. I have turn the nut at the buttom, till it won’t go any more. What do I do to improve the time to make it faster. Thanks, Seth

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