Cut one end of each 6-foot beam with a miter saw, angling the end at 30 degrees.
Place the two 8-foot beams together, so their ends are flush. Measure 2 feet from each end and mark the tops of the beams with a pencil at these locations.
Place one of the 6-foot beams on the floor, so the angled end is flat on the ground. Place an 8-foot beam on the ground on each side of the 6-foot beam, so the bottom end of the 6-foot beam is positioned between one of the sets of marks you made. Keep the ends of the 8-foot beams flush. The 6-foot beam should be angled, so the top end of the beam hangs beyond the ends of the 8-foot beams on the ground.
Clamp the 8-foot beams into place and ask a partner to hold the 6-foot beam steady as you drill four 1/2 inch holes through the two 8-foot beams and the 6-foot beam in the area where they overlap.
Remove the clamps, then insert the bolts into the holes and screw them tight with a tightening washer and a nut on the threaded end. Use a wrench to tighten the nuts.
Insert the other 6-foot beam in the space between the 8-foot beams at the other end where you made the pencil marks. The top end of the 6-foot beam should hang out over the end of the 8-foot beams. Clamp the 6-foot beam into place.
Drill four holes through the space where the 8-foot beams and the 6-foot beam overlap each other. Remove the clamps and insert the bolts. Put a tightening washer on the threaded end of each bolt and screw a nut on to hold the bolt into place.
Lay one 4-foot beam centered beneath each end of the 8-foot beams so that the 4-foot beams and 8-foot beams are perpendicular. Use metal connector brackets placed on either side of the 8-foot beams to nail the 8 -foot beams to the 4-foot beams.
Drill a half-inch hole through the narrow side of both 6-foot beams. The holes should be located one foot beneath the top edge of each beam. Insert a 1 inch eye bolt in each hole, with the threaded end pointing out. Place a tightening washer over the threaded ends, then a nut over each washer. Tighten the nut with a wrench. Hang your hammock from these eye bolts.