My first balance board was homemade. It consisted of a chunk of discarded formica counter top (say roughly 14" x 24"), a couple drilled pieces of discarded plexiglas, a length of metal doweling and a piece of paper marked off in 1/8" intervals. I attached the plexiglas to either side of the formica chunk so that the holes in each were aligned and ran the dowel through the holes. I placed the paper so that the centerpoint was 13-1/2" from the center of the dowel. When the extra-longs were introduced I added a second piece of paper in a configuration reminiscent of a slide rule.