I'm a teacher who uses Circuit Playground Express microcontrollers. Amazing device, but when you have a classroom set, plus battery packs, croc clips, etc., it's handy to be able to organize them. This hanging rack lets you keep the usb cable attached if you want. Use magnetic tape to secure it to a metal surface, or use double-sided foam tape. (The magnetic tape I used came unstuck after a few days on one rack, so I attached the strips again with a quality super glue.) I created it with six rather than five CPX slots because six is one better than five.
I strive to avoid using support in my prints, but I ended up needing to use it and a plate adhesion layer both here.