Once you have some type of weight attached to the motor shaft to create a good vibration, fasten the motor to some type of cabinet to contain the unit. There are two ways to do this, but each will give a different result and type of clunking. The simple method is to fasten the motor to the inside of whatever cabinet you plan to use so that the weight is allowed to spin freely while the motor is held solidly in place. This method will not make much noise, but will vibrate the cabinet and whatever it may come in contact with so that the noise is generated by the actual shaking of your target machine. The second method, which is the one that I used, makes a lot more noise by letting the motor flail all over the place while randomly striking the sides of the cabinet with the spinning weight. This method makes a truly nasty sound that will make your victim’s eyes light up when he or she hears it. This noisy method requires the motor to be mounted on some type of spring or rubber pad so that it can jostle around a bit, letting the weight strike the insides of the cabinet randomly. Figure 4-29 shows my spring-mounted motor mount made from a pair of bolts, a spring and a wire wrap. Again, use some creativity, and whatever parts you have collected to make your system work.
The rest of this project is easy. Just solder some wires to your motor, a switch and the battery so you can turn the horrible noise-maker off once the joke is over. Figure 4-30 shows how I mounted the parts on to the lid of my cabinet so that the guts can be dropped into the box when the lid is installed. If you choose the spring-mounted motor system, ensure that your wires are securely soldered to the motor terminals, and try to use a wire that can take the repetitive flexing it must endure as the motor vibrates all over the place. Some careful tweaking of the motor mounting position in the cabinet may also be necessary to avoid having the weight come too close to the
Figure 4-29 A spring mounted motor for serious noise
Figure 4-30 Parts ready for installation
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Project 16—Serious Car Troubles
motor so much that it’s almost impossible to hold on to.