Speeding up your pendulum clock requires adjustments to the pendulum. The method of adjustment varies depending upon the type of clock you need to adjust. Most pendulum clocks are accurate time keepers. Adjust the speed when first taking possession of a clock, if the clock is not level, and to adjust for changes caused by weather.
Speeding up Your Pendulum Clock
Hold the pendulum in place with your hand. Kensington Clock warns that you must hold the pendulum still to avoid damage to the suspension ring. While holding the pendulum, turn the small nut beneath the bob. Turn the regulating nut a full turn to raise the bob. A full turn will speed up the clock by 30 seconds in 24 hours.
Speed up a mantle pendulum clock. Verify that the clock is level. Kensington Clock describes how to speed up your mantle pendulum clock. Turn the arbor or wheel on the face of the clock about a half-turn toward the F (fast) position. Set the clock to the accurate time and wind fully. If you notice the clock needs more adjustment, turn the arbor in the necessary direction and reset.
Adjust the speed on a pendulum wall clock. According to Kensington Clock, adjust a the nut on a rod just under the pendulum bob. Turn the nut to the right (clockwise) to speed up your clock. Completely wind the clock and move the pendulum to begin swinging.