I was looking around for something suitable to add thrust bearings to my Ender 3v2 and there was nothing that really suited what I wanted to do. Most of the ones that I've seen attempt to support the outside of the bearing and keep it centred.
This one simply slips into a F9-20M thrust bearing and then push it onto the shaft with the flange facing the coupling.
Fast to print and simple to install.
I've provided a .3mf file and an STL for those who want one.
Can be printed with PLA, PETG, or whatever you want
The author hasn't provided the model origin yet.