Vibrating plates are one of the hottest new equipment trends in upscale gyms. A plate large enough to stand on "vibrates" every muscle in your body while you do simple exercises or just stand there. NASA is interested in this technology as a way for astronauts to exercise in space – where there is no gravity and ordinary exercise equipment is largely useless. Some workout enthusiasts swear by this technology and others dismiss it as useless or dangerous. Several companies have sprung up to manufacture vibrating plates, but you can make your own from used parts that can be purchased inexpensively.
Find an old washing-machine motor. It can be purchased inexpensively at a junkyard or an appliance-repair store. Washing-machine motors are excellent for building a vibrating plate because they are used to running with uneven – vibrating – loads; they almost always have a flywheel, which you need; and they're designed to run in a closed container without overheating. Be sure you get the mounts and the stiff industrial springs that connect the motor to the frame.
Drill one of more holes in the flywheel of the motor; all the holes should be in one quarter of the flywheel. This will cause the motor to vibrate at a steady rate as it runs. Start with one hole and drill more of them to increase the vibration. Cheap, and therefore soft, metals are used to make flywheels, so they're easy to drill holes in.
Build a wooden frame to contain the motor; use the boards to build wooden steps on one side. Use the same axel mountings that the motor had when it was in a washing machine to attach it to the floor and to the center of the large plastic or wooden platform. Attach the edges of the platform to the wooden frame with large springs – you can probably get them from the same washing machine.
Wire up the “dead man's switch” so that the user can hold the switch to activate the vibrating plate, and release it to deactivate the plate. The switch is serving the same purpose it did on the chainsaw, snow blower or jet ski it was originally designed for. It's also a safety measure, because it automatically shuts off if anything goes wrong.
Many devotees find that it's better to use vibrating plates while keeping part of the body on solid ground. For example, they like doing pushups with their hands on the plate and feet off the plate.
Some research suggests that the vibrating plates may be bad for your cartilage.