Cut the ends of the 6-foot 2-by-4s diagonally at a 60-degree angle, using the saw. Lay an 8-foot 2-by-4 on the ground and place the two shorter beams diagonally on top of it, with the cut side aligned with the edge of the longer beam. Position the diagonal 2-by-4s so their free ends are as far apart as the length of your hammock.
Lay another 8-foot beam on top of the first, sandwiching the two outward-pointing diagonal beams between them. Drill three holes through each intersection and run bolts through them to secure the frame's structure, adding washers and tightening nuts with a wrench.
Lay the 4-foot 2-by-4s parallel on the ground, at a distance of 8 feet along their further edges. Stand the rest of the frame upright on top of these, crossing both beams perpendicularly. Drill through these intersections as well and bolt in place. Notch the upper ends of the diagonally vertical beams with a hatchet or knife and hang the hammock between them, using the notches to keep the ropes from slipping.