Threatened with the specter of destruction by falling shoe rack, I envisioned tying the thing to the wall for stability. The rack sellers claim a capacity of ten's of pairs of shoes, so keeping them from tumbling down would certainly be a good idea. So, the design is a swinging arm that comes down to clip on the shelf rods, thereby keeping the shelves from tilting away from the wall.

The design is print-in-place, 0.5 mm clearance. I found it to break free pretty easily, no supports required.

If I were to print these again, I would shorten the width...the hinge pin length...and print with higher infill. Because of the print orientation, I don't think the width added much to stability and the ultimate strength is determined by the lamination strength of the layers of the hinge pin, especially where it attaches to the swing arm. Hopefully if you want to print and agree with the changes, the OpenSCAD file will make it easy for you.

A followup note: I installed the brackets and despite kid glove handling, the hinge pins on two of them snapped...real easily. So I drilled the whole pivot out 1/4" and hot melt glued a 1/4" dowel core in to rescue the parts. So there's your spoiler alert. I would modify the hinge pin/arm piece to have a hole to accept a rigid core like the dowel or a nail or similar.

Update: I have added a hole in the hinge pin to accept a glue-in-place 4d or 5d common nail (have to clip a quarter inch off the 5d) to give this part reinforcement from cracking along build layer lines. Consider boosting the infill from 15% to 20% or 30%, too.

I originally envisioned using 4, one each corner of the rack to the wall. However, I only have two in place...at the top corners...and it's working fine. Yes, I could give the bottom a good boot (ha ha ha) and the rack would likely move but I have 40 pair shelved and it doesn't seem to want to. I letting the Imelda Marcos come out in me (just the shoes, not the corrupt part).

XYZ Printing da Vinci AiO 1.0

No

No

0.3

15%

An easy strength enhancement would be to double the infill percentage.

The screw holes are for drywall type screws.
It looks like it is performing well...one at each of four corners...but if I were to print again I would toughen up the brackets by designing hole in the hinge pin feature to accept a nail or similar with a bit of epoxy.