Wall Shelf Brackets - 1/2" plywood (FreeCAD)

Model as shown uses 4X 3.5mm screws and 1/2 inch (12mm) thick plywood from 2x4ft stock cut to 125mm for depth

Moderately parametric for board thickness, board depth, and screw sizing

Chose to print mine in PLA, 0.3 layer, 3 perimeters, 15% infill with 100% infill at screw bores and helper disks in lieu of brim (see images)

Not loaded tested :) Feedback welcome.