Help with building

[tweetlebeetle13085]

I am trying to build a little platform that has three connections on the bottom, so it can rock three different directions. I think I found a way to get it done with one motor, but I dont know what type of motor to use, or how to get the motor to randomly, or appear randomly change directions and speeds. The platform needs to hold about 50 lbs and be very safe. How can this be done.<p> Thanks a bunch, Ben

[jwax]

More details are needed.
"3 connections" on bottom?

[haklesup]

You need a motor that moves relatively slowly for only a few rotations then can quickly change directions and rate of speed. You also need this motor to provide very high torque to move a 50lb load in random directions (try tossing a bag of sand around to see how much torque we are talking about)<p>The only motor I see that fits all these requirements is a stepper motor driven by a digital sequencer of some sort. This stepper motor would need to be at least 1hp and be fairly heavy (someone else comment on required power please, I just guessed). A pseudo-random digital word generator could be connected to the stepper driver inputs to emulate random motion.<p>If you wanted to use a smaller or simpler motor, you would need to compensate with a rather complicated mechanical gear box to gain the mechanical advantage you would require.<p>In the end, it may also be eqivelent to use three motors to move it in the X,Y and Z directions. These motors could be less powerful and with mechanical adaptations could be simpler AC motors with a way to start in either direction.