Assemble a Clock with Weights and a Pendulum
3rd Floor / No. 11
Summary
The clock model offers insight into the basic operating principle of a mechanical clock, with the possibility for the young and the not-so-young to assemble it themselves.
How Does the Clock Work?
The clock mechanism consists of gears, a weight, a pendulum, and an escapement.
- Weight is the power source that creates force. This force drives the entire clock mechanism.
- Gears enable the transmission of movement from the weight to the hands. They are of different sizes and have different numbers of teeth.
- Escapement is the part of the mechanism that stops the rotation of the gears.
- Pendulum moves the escapement and thus sets the beat of the clock. The faster the pendulum swings, the faster the “ticking”. It is the most basic part of the clock – we determine time by counting the swings.
How Does the Number of Teeth Affect Gear Rotation?
The gray and white gears each have 10 teeth. If we turn the gray one one revolution, the white gear will also turn one revolution, but in the opposite direction.
If we increase the number of teeth on the white gear to 20, the white gear will turn by half a revolution for one revolution of the gray gear.
If the gray gear has 20 teeth and the white gear 10, the white gear will turn twice for one revolution of the gray gear.
Assemble and Observe
Try to assemble the clock mechanism. Below are some steps with hints.
You can follow them or try to assemble the mechanism without help.
- Assemble the mechanism from gears driven by a weight. Observe how the mechanism behaves when you add or remove gears.
- One of the gears has a slightly different shape – it is used in combination with the escapement to which the pendulum is attached.
Add the escapement with the pendulum to the assembled mechanism. Try to get the weight to drive the gears while the swinging pendulum moves the escapement and stops the rotation of the gears. - Observe how the mechanism behaves if you change the length of the pendulum.