Check out my latest project! http://scratch.mit.edu/projects/23269519/ Click the green flag and watch. Press space to change how the disk moves. While I've done quite a few projects that involve plotting 3D points given an x and a z coordinate to find a y coordinate, I've never before made a project that finds a y coordinate given a radius and an angle.
Thanks to JeremiahMacDonald for many to all scripts, I just edited parts of the program.