I made a large spool shelf. I used threaded metal rods. Put the spools over the rods. Then a 1 inch plank which had 4 holes drilled in it, all at equal distance from the edge. I had four shelves. It was over 5 foot high. I used it for plants. The spools have to be the same size on each rod, at the same level to keep it balanced. Different sizes can be used. To keep it all tight, it has a nut screwed to the top and bottom The top and bottom spool was drilled with a larger hole to cover the nuts.