Make a frame from two pieces of wood approximately 2 inches by 1 inch by 36 inches and two pieces that are 2 inches by 1 inch by 36 inches. The longer pieces make the longer sides, while the shorter pieces make the smaller sides. Screw two 2-inch wood screws through each corner of the trunk, where two pieces of wood meet.
Apply a layer of wood glue to the top edges of the frame. Carefully place a plywood board 24 inches by 36 inches by ¾ inch on top of the glue. Clamp the plywood to the frame and let it dry overnight. Repeat steps one and two, making the top of the trunk.
Remove the clamps and turn the bottom frame upside down so the plywood sits on the floor. Set a wood board 1 inch by 1 inch by 36 inches on top of one of the longer sides. Screw a 2-inch wood screw through the top of the board and into the frame. Attach 10 boards to each of the longer sides in the same way.
Attach 10 boards measuring 1 inch by 1 inch by 24 inches to the shorter sides of the trunk. Place one board on the shorter side and screw 2-inch wood screws through each end. Keep stacking the boards until the side has 10 boards. Repeat this step on the other shorter side.
Set the top on the trunk and lay two hinges on top, approximately 2 inches from each end. Screw two 1-inch wood screws through the hinge and into the side of the trunk. Screw two 1-inch wood screws through the hinges and into the top of the trunk.