A pendulum clock is out of beat when the ticking does not sound even (or more precisely, when the left tick and the right tick do not occur at the same angle of the pendulum from its point of rest). A clock that is slightly out of beat may run; if the beat error is severe, the clock will be unreliable or may not run for more than a few seconds.
Note: You can put a clock in beat by tilting it to the left or right until the ticking sounds even. If it looks too much off level to suit you, follow the instructions below.
These directions apply to American antique clocks of the “Connecticut” type such as Sessions, Ingraham, Gilbert, Seth Thomas, Waterbury, New Haven, etc., having an easy to bend crutch made of brass wire. The same principle applies to other clocks, but on some clocks the crutch is wide and hard to bend, on French clocks the escapement is delicate and you must be very careful, many modern clocks have a slip clutch for beat adjustment, some modern clocks (especially grandfather clocks) have automatic beat setting, and many precision clocks such as Vienna regulators (and some grandfather clocks) have a beat setting screw near the TOP of the pendulum.
Wall Clock: Clock should be leveled and fastened to wall at both top and bottom so it stays in place. Remove the hands and dial.
Shelf or Mantel Clock with pendulum in front: Place the clock on a level surface and remove the hands and dial.
Mantel Clock with rear pendulum: Place the clock on a level surface with the back facing you, and open the back door.
Refer to the View A and View B in the illustration above and follow the steps below to put the clock in beat.
- Move pendulum to the left or right until the escape wheel escapes from one pallet to the other. Release pendulum and see if clock keeps running for several seconds.
- Stop pendulum, and move it in the other direction until escape wheel escapes. Release pendulum and see if clock keeps running for several seconds.
- If the clock keeps running when started from both the left and right sides (or nearly so) clock is in beat.
- If the clock keeps running only when started from the left, slightly bend the crutch wire to the right, as shown by the arrow in view A. To bend the crutch wire, grasp it in needle nose pliers (or your fingers) about 1/3 of the way down from the verge, and bend the free end slightly with your fingers.
- If the clock keeps running only when started from the right, slightly bend the crutch wire to the left, as shown by the arrow in view B. To bend the crutch wire, grasp it in needle nose pliers (or your fingers) about 1/3 of the way down from the verge, and bend the free end slightly with your fingers.
Repeat steps 1) through 5) until the ticking sounds even. You can make the most precise beat determination when the pendulum is taking the minimum possible swing that will make the clock tick on both the left and right pendulum swing. A larger swing may mask beat errors.
Note: it is better to use a wire bender (a small metal rod with a slot in it) instead of pliers, but the pliers will suffice if you are careful.
Troubleshooting: Make sure the pendulum rod is not touching the front or back of the crutch loop – bend the crutch wire if necessary. Make sure the sides of the crutch loop are parallel and that there is slight clearance between the pendulum rod and the sides of the crutch loop.
When I was a youngster I experimented and learned how to put a clock in beat, and can do it almost without thinking. In the instructions above, I have tried to put my procedure into words and drawings suitable for the clock owner with some mechanical know-how. Please feel free to make a comment on how to make the instructions more clear!
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