Caption

Car gears. Computer-aided design (CAD) of the driving gears of a car. Gears allow rotational motion to be transferred from one component to another. The speed of the gears' rotation is dependent on the number of teeth they possess. A gear with fewer teeth than the driving gear will rotate more quickly, and one with less teeth, more slowly. CAD is a tool by which objects can be completely designed in three dimensions, and tested before they are built. It saves time and money, as incorrect designs can be corrected quickly and easily. The data from the computer can be fed into a mechanical production line, and the object can be built automatically.