Well this project seemed to evolve from another project. I was going to make a Chinese repeating crossbow, but I ended up scrapping that plan and here's why . I started first by making a bow. I used high carbon steel spring tempered. But it was extremely hard to draw, I had to stand on it to draw it . So I thought if I add a pulley system it would make a better compound bow for a powerful single shot crossbow (which I'v never attempted to build a compound xbow before). I found some high strength brass ball bearing pulleys where I live for only .25 USD, I purchased all they had for 3.50,. Made some steel mounts for the pulleys. I used paracord for the drawstring.