During CiscoLive Europe, we normally have several hot-spare compact switches, connected and running, ready to be fine-tuned and sent to be deployed.
Keeping them on top of each other is not a good idea - they get very warm. We did not wait until the magic smoke appears, but we prefer not experiment. So, we made a harness in which the switches are standing vertically - this gives a very good cooling.
The first version of harness was done from packing plastic foam. It worked for a couple of years, but it is bulky and a bit fragile.
This is a remake of the same rack, but using the CR-30 3d printmill. I am not sure if the average 3D printer will work - the longest dimension has the length of 50cm!
The files are both FreeCAD and .obj exports
Enjoy!