Hello everyone!
I built a shake table out of K'NEX for the purpose of teaching structural dynamics. I have used it to teach K-12 students, college students, and professionals. All you need is K'NEX, some metal washers, and a variable speed drill.
Instruction manual is attached (developed by me, using Autodesk Inventor). Feel free to use it or modify it, I published it under a creative commons license. More info in the manual.
-alpal