Using 3/4" PVC and 1/4" Plywood as well as the printed parts you can make a shelf of any size. I keep mine small and only put light stuff on them but this could also be scaled up to support more weight. The wood does fit tight so you might have to sand the wood a little. I print and had designed to print from the flat edge up. No supports should be necessary.

**5.2 mm (1/4") Sandeply