| Pendulem Clock: |
| To most people actually building a clock seems like an almoast impossible task. Here you will learn how to make one out of just about anything. I made mine out of an Erector set but after you understand the basic priciples you can make a clock out of Lego, wood, or anything that you have around the house. It is cool to "watch" and makes a great science fair project! |
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| My clock: |
| Before explaining how to actually make a clock I'll explain how this kind of clock works. After that you should be able to figure out how to make one by yourself but I'll show you how mine is designed. |
| The "pin wheel" escapement clock: |
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| In order to keep time we need a source of evenly measured oscillation. In this case a pendulum is used. Without friction (and with constant gravity) a pendulum will keep swinging for ever with a constant frequancy (the time that it takes to complete a swing will be constant). however in reality there is friction and so in order to keep the pendulum swinging a restoring force is needed. In this case the weight supplies this force. |
| THEORY: |
| HOW THE CLOCK WORKS: |
| As the pendulum swings to the left (see the diagram) the top pallet lifts the finger and lets the "pin wheel" move forward(by force of the weight). The bottom pallet the swings up and stops the wheel by catching on to a pin (in the diagram this is the pin in the "2:00" place). Then the pendulum stops and is given a little push by the weight - the pin pushes on the bottom pallet-this is the restoring force. As the pendulum swings back to the right the finger is released and it falls back down. This stops the weight from quickly falling and hitting the floor. With every swing of the pendulum the pin wheel rotates around one space. This spin is the transmitted to the "clock work" which spins each of the hands the proper amount. |
| clock diagram: |
| The weight is tied to a string which is wrapped around the axis of the pin wheel. The weight spins the pin wheel to the right. |
| To learn how to actually make a clock, goto the link below! |
| If anything is unclear or if you have something to add, write to the e-mail address given on at the home page! |
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