For game devs, pixel artists, or anyone interested in mazes or random 2D map generation check out this resource on Wang Tiles. You'll want to bookmark it.

I made a Scratch app to demo some 2-edge Wang Tile sets and decided to make my own. I wanted to do something original, so I created this animated set of chains and pulleys. Check it out to see this set animated along with others from the page above. https://scratch.mit.edu/projects/127701037/

In the files to my set, you get the chains and gears both with and without a background in the png and everything split into seperate layers in the psd. There are 4 sets of tiles for four frames of animation, all made to loop and tile randomly according to Wang Tile rules (all edges must match)