The inside structure was built using the three center boards of the pallets. The lengths of the stand are the length of a pallet support board. I cut one in half to create the depth on each end. That made the square for the top and I did the same for the bottom. I then used some more of those boards to connect each square frame vertically. At that point, I had my frame to start slapping the boards on. From that point it was just cutting off extra length of boards, sanding and painting.