Three-Axis Drawing Machine
Hacked together from recycled printer parts, some bits of an old RC car, and stuff that I found in the scrap bin. Not terribly precise, but lots of fun to build.
I am not above using tape and glue in a pinch. That arm could really use a gear reduction though.
This is how you get a radial arm to draw a straight line!
This part of the assembly makes an extremely satisfying sound.