This project began when my son chose to investigate block and tackle for his 1st grade science fair project. I was going to zip down to the local Home Depot and buy the supplies, but then thought, “I should just print em!”. I iterated the design a couple of times before I printed the first full assembly. Then printed 3 more full assemblies. Works great! You will see that there are two types of sheaves, a single and double. The double actually should have been two separate thin sheaves next to each other within the pulley plates. The rope had very little friction, so I don't think much advantage was lost. Wooden dowels (1/4”) were used to hold the hooks, eyes and sheaves between the side plates. You can decide whether to use a hook or eye on each end.