Whenever we show you a new engine, the designer usually has an animation of some sort to demonstrate how it works because a static drawing or display can be a bit obscure, but being true gearheads, you can certainly look at some gears and figure out how they work, after all, they're just gears. Well, for the most part, that's true, but every now and then, even with what appears to be a relatively simple arrangement, if the gears have a complex shape, the actual movement can take a bit of spatial imagination to figure out exactly what happens as things begin to rotate.
507 mechanical movements is one of those sites with drawings of gears and levers of varying complexity and even a quick glance will show you it's not always easy to accurately predict how things will work. They have been slowly going through the drawings and animating some of them so you can see the gears in action. (Just note, only the diagrams in color are animated so as you go through the pages you can quickly pick them out.)
It's a nice bit of work, but I see an opportunity here for someone to make some kits of all of these movements for the mechanically inclined student. There's nothing like seeing a real mechanism you can touch and feel, moving in some unexpected way, to capture a little bit of the wonder lost as kids experience everything through a computer screen.
Kids need some hands on experience
I had some neat plastic gear sets when I was a child that I could rearrange and turn to see how the motion transferred from one to the next and then there were all of the mechanical alarm clocks that eventually fell prey to my screwdriver. What a wonder those were inside! But who has a mechanical alarm clock these days? It's a pity, because many kids learned a lot and careers were started because of early explorations inside those and similar devices common to every home 50 years ago. Now, it's computers, all day and everywhere.
The 507 site we're talking about here was mentioned a few days ago on Hacker News and one of their comments led to this video about analog fire control computers. Gotta love it, especially when the intro to the video says "Shafts Gears Cams and Differentials." How could you not like that? The multi variable problems these computers were designed to solve were very complex and doing it with shafts and gears just makes me smile.
Sometimes I think you guys might need a little diversion. Have fun!