This is a shelf support in several sizes for actual use.

Because FDM 3D prints are (much) weaker in the Z-axis, the design was made to be printed horizontally. For this reason the diagonal brace has only the thickness necessary to be an effective support without interfering when mounting the support.

Print with a decent infill and shells this is actually quite strong.

Please use screws with FLAT heads, not the conical ones that are used for wood. Conical screw tend to split the prints apart. Screws to be uses are of the 4 mm variety with a 8 mm screw head.

I have included four different models, with brace lengths of 50, 90, 120 and 150 mm in length.