I'm working on a book starring the 6 Simple Machines. I already did one book called "Simple Machines Made Simple." I'm now doing a follow up book that I'm thinking will likely be titled "Simple Machines Made Complicated" (or maybe Complex). Each page is a working mechanism. Kind of like a book full of fidget toys. So I want to have one page for each simple machine, and some of the progressions to complex are easy i.e. (wheel -> gears), but the one I'm currently stuck on is the pulley. My first book had a compound pulley, but now I'm struggling to figure out a more complex pulley example that I can recreate with less than 5mm for the page thickness. My first idea was to do like a roman blind mechanism with a pinch-stop type thing for the cord, but the more I played with it, the more I felt like this wasn't any different from the first book. I also like the idea of a chain hoist type mechanism, but I'm worried there isn't enough visual pay off for what you put into it. Like you move this chain thing around a bunch, but you only get a very small movement on the other end. Anyway, that's I'm working on. It might take me another 6 months, but I'm sure I'll figure something out ;)