Summary

Make use of vertical space by neatly attaching things to the poles of wire rack shelving!

A 3d printable clamp for mounting things to wire rack shelving units. These slot in a M3x0.5 or M4x0.7 hex nut, and a screw can either be used to directly mount some object or as a keyhole stud. Can be used to mount power strips, routers, networking hardware, and other objects to a wire rack shelf unit.

REQUIRES EXTERNAL HARDWARE: M3x0.5 hex nuts and screws (minimum 8mm threaded length).

Designed for wire racks with ~25.4mm (1 in) pole diameter.

Each object is one half of the mount, you'll two for each mount. Typically, I use the single-M3 version as the backing. You need a M3x0.5 nut and screw to mate the two halves. The M3x0.5 nut lightly press-fits into the hole. Both halves are identical and the socket can take either a nut or screw head.

The "single" version has the hex nut at the level of the ribs in the pole. The "tall" version has a longer track for the hex nut, allowing flexibility to match mounting holes of the object being mounted. The "3x" version has three hex nut tracks at 45 degree offsets. The "M3" vs "M4" versions have different hex nut tracks specified for M3 or M4 hex nuts (note, the mating screws and nuts for the two halves are always M3). For M2 (for some sensors), I use a 3d printed adapter to fit a M2 nut into a M3 size.

I typically print these in PETG for strength, but PLA can work for lighter applications. Brim not needed. Examples printed on a Prusa Mini, 0.4mm nozzle, 0.2mm layer. If using PETG, make sure to set retraction settings for print quality. I've used these to mount things as light as network switches and power strips, and as heavy as a Dyson vacuum holder (which holds part of the weight of the vacuum itself).

FreeCAD sources available here: https://github.com/ducky64/wire-rack-mounter
These are spreadsheet-parametric designs and can be customized for your applications.
Less common adapters also available there.