These snap-together parts form a bike chain. Not recommended for actual use on bicycle. The intention with this was to come up with a chain drive. I haven't found any cool uses yet, but that's another project!!!
I wasn't entirely sure how a bike chain worked, so I decided to do some research before I made my own. Check out the pictures I've attached for how to assemble it.
I'm printing in PLA. I would recommend printing in medium or high resolution for the rivet. Everything else can be printed on low quality.
COMMON PROBLEM: If the chain plate seems to be sliding out from the pin, I would recommend printing the pin a little bit bigger. These are intended to snap together and stay together (but can be removed with some applied force).