After finding a level area, start by constructing the a-frame sides. Lay out the a-frame shape using one 2”x4”x12”, one 2”x4”x8’, and four 4”x4”x8’ pressure treated boards. The 2” x 4” x 12’ will be cut into half. Each half will be used for the lower brace of the a-frame.
Use the 8’ board for the angle braces from the a-frame of the crossbeam and for the top brace. Cut the 8’ board in four parts- two 1 in. long and two 3 in. long. The 1’ cuts will be used as the top a-frame braces, while the 3’ cuts will be used as the angle braces from the a-frame to the crossbeam.
Arrange the 4”x4”x8’ boards into an ‘A’ shape and secure them with galvanized lag bolts. The 3’ braces will go to the outer side of the frame and the upper a-frame brace will be set in the a-frame. Tack through the lower brace into the erect a-frame supports and tack through the erect a-frame supports into the top brace.
Hold the a-frames upright. Screw one brace board to the a-frame and an additional one facing the opposite direction on the opposite part of the frame. Place the a-frame so that it stands evenly on the ground, and fasten with another screw in the braces so the frame can stand alone. Do the same procedure for the other a-frame. Put you frames 9 feet apart from each other. The crossbeam will stretch out by 2.5’ on each side.
Raise the 4” x 4” x 16’ board (the crossbeam) up so that it rests on one of the a-frames. Then have the board rest on the other frame and attach the crossbeam to the a-frames using metal a-frame brackets.
After that, place the remaining angle braces on opposite sides of the crossbeam slanting to connect to the top brace of the a-frame. Attach the braces using metal angle brackets.
Fasten your trapeze eye bolts and your swing. For the trapeze bars, bore a hole two inches from each end and an additional one 1.5 feet from there.
Bore a hole six inches from each side of the angle brace. Bore the other two holes 1.5 foot from there. Bore two 18-inch wide holes in the center of the other two holes, providing a space for two trapeze bars and three swings.
Install the eye bolts and suspend the trapeze bars and swings.