I recently finished my shuriken project, with a button that spins or stops spinning a red & black shuriken. The shuriken itself is made of laminated plastic and hand cut to isometric dimensions. There is a button at the base of the shuriken which is connected to both a battery and finishes the circuit to the motor holding the shuriken.
Once I was done building the shuriken, I had some time left to decorate the shuriken. After painting some of it a primary base red, I spun the shuriken while dropping paint on it from above. This created the pattern seen on the paper to the right. -->
I really enjoyed this project because it gave me a chance to have some freedom with my creativity and what I was able to create.