How to make a bungee launcher and building tips

3 3, 4 T connector 2 3, 4 X (four connection cross joiners) 5 3, 4 end caps 6 3, 4 90 s 4 1 T s 4 1 to 3, 4 adapters 3 10 3, 4 lengths of PVC 1 small can of PVC cement 2 3, 4 metal pipe brackets 1 3, 8 X 3 bolt or lynch pin (unthreaded for release pin) 2 1 welded steel rings 5 feet nylon cord or shoe lace 10 feet foam pipe insulation 3 plastic tent stakes heavy duty 20 feet bungee or surgical tubing cheap fish scale (hang