YubiKey 5 / 5C NFC Lanyard Holder

I was designing something small to go on a badge lanyard to hold a yubikey as I wasn't pleased with the options available. I wanted something where the lanyard loop had layers aligned in such a way where it was not held together by layer-to-layer bonding. Then, I realized that instead of relying on friction with the USB port, I could instead interface with the hole at the other side of the key.

This model uses two bumps to interface with the hole on the yubikey. It is designed to be a bit of a tight fit and this the curves allow you to squeeze it to open it up a little.

It should be printed with the cavity facing up. I printed with PETG to survive sitting in a car but any filament will work. Smaller layers will make the bump transitions smoother - you can use variable layer height to make only that part small but you'll get some artifacting on the outside.

I've included a fully parameterized F3D file. Just go to Modify → Change Parameters and each paramter has some decent comments describing what it does. The main one you may need to adjust is the bump height.