How do Pendulum Clocks Work?

pendulum clocks

Nowadays, you can see pendulum clocks used for aesthetic purposes. But did you know that before we had the modern clocks today, pendulum clocks were used every day to tell the time? We might not be familiar with how it works now, but it’s important to know how pendulum clocks work. Read on to know more about how this works.

How do pendulum clocks work?

A clock with a pendulum uses the movement of gravity to measure time. Most clocks have some form of balance wheel or oscillator that moves back and forth in regular motion. Pendulums are simply one type of oscillator.

The free end of the pendulum swings back and forth, which makes an impulse on the clock case each swing. The mechanism inside counts these impulses and converts them into rotations of the hands-on clock face, indicating the time.

pendulum clock

How does a pendulum clock keep swinging?

Winding your mechanical pendulum clock is essential for keeping it running properly for as long as you want it to run! Here’s how to do it, step by step:

  1. Put down newspaper or other covering on your floor and cover the watch glass with a cloth.
  2. Use your screwdriver to remove the back of the clock. If you can’t do this, then carefully look inside for another way to access the pendulum area. You will see two pieces of metal that form an almost complete circle, except for a small gap between them. These are suspension springs and hold up the bob (weight on top of the pendulum). 

Some clocks have only one spring; others have two or more springs in series – so if you see more than one, there is usually no need to take them all off, but some people find it easier to clean and oil while they’re detached from their holders and hanging free anyway. Sometimes these springs come out easily by themselves, sometimes they won’t budge, in which case you may need pliers or tweezers to take hold of them.

3. Turn the pliers round so that the jaws point towards the metal suspension springs – not you!

4. Press your screwdriver into one of these gaps and push towards yourself to twist off the suspension spring. The other one will pop off at the same time, so if it doesn’t do this, try wiggling your screwdriver around a bit more softly – but be careful not to bend or break anything, especially if the spring is stuck on particularly well! Remove both suspension springs.

5. Now turn your clock upside-down. WARNING: Don’t get any oil on the glass

6. Use your tweezers or pliers to carefully remove the small weights at each end of the pendulum. You may need to flick them up with your fingers. Don’t drop these – they are surprisingly heavy! Once you have removed all four, set them aside safely out of reach of children and pets. Here’s how the clock looks once the pendulum has been removed:

7. Use paper or cloth to soak up any drops of oil spilled onto the glass. Make sure there are no droplets left for fingerprints on it before putting it back together again.

8. Now, use your oil can to drip two or three drops along one side of each weight, where it is attached part along its length to the pendulum rod. Line up the weights carefully with their original positions, and put them back in place.

9. Now, make sure your pendulum is hanging completely free – by turning your clock over again if necessary – and use a soft cloth to wipe some oil onto both ends of the bob. Make sure you get it around the edges so there are no gaps where dust could get in!

10. Once you have fully reassembled your clock, turn the hands forward to the correct time on a working clock before plugging it in again and checking that everything is going well. Wipe away any excess oil that might have got on the glass or frame, and your clock will be ready for another decade (or two) of service!