Oskar van Deventer is a Genius!
I first found this guy searching for gear arrangements that I could create; I found a video in which Oskar van Deventer shows off a gear box with an 11 MILLION to 1 ratio. I went on to watch at least a dozen other videos of things he's designed... each more charming and fascinating than the last! He designs gears, mechanical curiosities, puzzles, and interesting interlocking jewelry. It's all mind bending! All of it!
Check out his YouTube channel: https://www.youtube.com/user/OskarPuzzle