Quarter sheet sanding block

This sanding block was designed to fit a quarter sheet of the standard sandpaper found in the US. A full sheet is 9 in x 11 in (22.8 cm x 27.9 cm). The bottom of the sanding block is 100 mm wide and 110 mm long, which allows the block to grip paper with a minimum of unused paper. Print the bottom flat on the print bed with support on everywhere, which supports the bolt slots. Print the top flat on the bed with the handle on top with support on everywhere. After removing the support, slide 1 inch 1/4-20 bolts into the slots and press fit nuts into the tops of the knobs.