In order to build a backyard swing arbor, you will need the following: 2x4s, 1x6s, a bench swing, 4x8' sheet, a drill, carriage bolts, galvanized nails, and screws.
Cut 4 2x4's to 87". Cut a notch 3.5x1.5 in each, at the corners. Cut 2 2x4s to 15" each. Lay the 87" out on a flat surface, in a parallel fashion. Lay the connectors across the top of it. Align the notches. Make sure the sides are flush. Drill holes through the connectors.
Drill holes through the base and...