Build a base frame 7 feet long and 27 inches wide, using deck screws to attach 24-inch 2-by-4 end pieces inside the 84-inch 2-by-4 side pieces. Use two deck screws at each corner, countersinking them a bit so they can be capped with a wood button or covered by wood filler. Build two deck supports the same way, using two 30-inch 2-by-4s and two 24-inch 2-by-4s for the head section and two 54-inch 2-by-4s---place one end piece so that half of it sticks up above the foot deck frame and use only one deck screw on each side---this end piece will be used to attach the base and foot deck frames together.
Attach the 14-inch 2-by-4 legs on the inside of the base frame about 18 inches in from one end of the frame; about 6 inches should form legs below the bottom edge of the frame and 3 1/2 inches should stick up above the frame as an anchor for the deck frame. Drill holes for one carriage bolt on the side of the frame and sink the bolt through the leg so the bolt heads lie flat in the wood. Repeat on the opposite side and brace the legs with a 2-by-2-by-21 inch piece, using one deck screw on each side.
Turn the base frame over the foot deck frame and match the edges; the 2-by-4 end of the foot deck frame should be near the center of the base frame. Attach the legs to the foot deck frame with carriage bolts in the same way as you attached them to the bottom and drive deck screws through the base deck frame into the inside end that is standing up into the base frame.
Build the wheels by rounding the 2-by-8-by-8 inch squares to circles. Attach 2-by-6-by-8-inch axle supports on the insides the same distance from the head end using deck screws from the inside. Trim the corners so that they don't bind if the lounge is tipped too steeply. Turn the assembled frame over and measure for axle placement on each side up about 2 to 2 1/2 inches from the base of the axle support---your wheel will drop about 4 inches from the center of this mark. Trim some wood off the support if necessary. Drill a 1-inch hole through each support and the centers of each wheel. Push a 36-inch wood dowel axle through and secure it with a cotter pin or small dowel.
Attach one end of each tilt support to the head deck frame with carriage bolts so they can swing and attach a 1-inch dowel brace between them with deck screws. Notch pieces of wood and screw in place on both sides to hold the tilt supports. Attach the head deck frame at the sides with cabinet hinges and wood screws. Turn the assembled frame over and lay slats on the deck, leaving even spaces between them; screw them in place with wood screws.