Here's a kinetic piece from a while back, as much science as art really. No preliminary plans or drawings (animations and diagrams were produced later)....
Materials - Scrap plastic, coathanger wire, bicycle parts, a bearing set from a "Lazy Susan", lots of nuts and bolts (that I actually had to buy) and three thirty year old exhausted ceramic magnets (selected for their uniformity of weight).
Tools - Two pairs of needlenose pliers, a screwdriver, a pocket knife, a hacksaw and a file.
A uniquely balanced mechanical arrangement, its motion is pendulous, but unlike a simple pendulum which has two possible positions of equilibrium (stable when down and un-stable when up), this pendulum actually has four possible positions of equilibrium.... two un-stable positions alligned with the force of gravity (up or down vertically) and two stable positions perpendicular to the force of gravity (positioned to either side horizontally)....
With repeated periodic displacements of as little as five to seven degrees its rate of rotation rapidly approaches about 100 to 150 rotations per minute over the course of just eight to ten repetitions, all while overcoming only negligible frictional resistance from the main axel (equipped with bearings). It may have some applications for extracting rotational motion more efficiently from wind and wave and maybe a couple of other things too, or it may just be a work of art....