Summary

This is a part designed to be used with an inexpensive shelf bracket and lengths of 1"x2" board (actual size 0.75" x 1.5"). I used very inexpensive shelf brackets from Amazon (link below), drilled a couple of extra holes and put a screw up through the bracket, through this 3D printed part and into the boards. Please see the video for more explanation.

Printed on an Ender 3 with Polymaker Polyterra PLA. Print on it's side using 30% or more infill. No supports required.