The length of the pendulum determines the speed of the clock. The longer the pendulum is, the slower it swings. To change the speed of the clock, we can move the pendulum weight up and down, and then change the effective pendulum length from the center of gravity of the pendulum to the hook to shorten or lengthen the actual pendulum length. You can move the pendulum up and down by turning the adjusting nut on the pendulum.

Turning the adjusting nut counterclockwise from top to bottom will shorten the actual length of the pendulum and speed up the clock. Turning the adjusting nut clockwise will lengthen the actual length of the pendulum and slow down the clock. Turning the adjusting nut by 1/3 turns is equivalent to adjusting the speed up/down for one minute every 24 hours. Please make sure there is no gap between the pendulum and the nut, and pull the lower pendulum if necessary.

Clock principle

The mechanical power of the clock is still provided by the heavy hammer, but the swing frequency of the escapement is controlled by the simple pendulum. The L-shaped rod connected with the main shaft of the escaper extends to the simple pendulum, and the head of the L-shaped rod is bifurcated, which just blocks the rigid pendulum and drives the L-shaped rod to rotate when the simple pendulum swings, thus transmitting the swing frequency to the escaper.

The advantage of pendulum clock is that the frequency of simple pendulum has nothing to do with its initial force, but only with gravity and pendulum length, so that the punctuality mechanism is really no longer interfered by the power mechanism.