I created this rack for my common 3D printer tools. Namely, 4 allen wrenches (for printer), 3 small open end wrenches (for hot end), tweezers, hemostats, and small side cutters. Mine is mounted inside of our printer enclosure using two screws. This rack keeps our most popular tools from getting misplaced.
The example shown is printed in ABS using 6 wall loops, 35% infill and no supports.