Sanding block

Hello! I would like you to present you my version of a manual sander. I have recently painted a wall and i was missing this tool, so i decided to design my own one. Below you can find a detailed assembly guide, so you can follow along if you decide to print it. The only thing that you need to buy for this design are 4 stainless stell hex drive flat head screws (M8 x 1mm thread size) 16mm long and obviously the sandpaper.It is also important to note that for this design a rectangular sandpaper is