I have purchased several sanding blocks over the years, and I’ve never found one that I really liked. I had some extra maple laying around the shop, so I turned it into 2 sanding blocks. They are 6-1/2″ long & 2-3/8″ wide. The top and bottom halves are held together with a 1/4″-20 bolt, and a custom knurled nut. The most time consuming step was using the belt sander, to give the tops a gentle arch. The following are some pics of the model & a finished block.