I bought a bunch of keyboard switches on ali express and had a few 608 bearings left over from a previous project... this was the natural consequence.

I used a 608 bearing (friction fit, should be pretty tight) and sprayed it with some wd-40 for more free movement as this is a pretty low-load application. The switches are friction fit as well, I just used whatever generic ones were cheapest on ali express and have been playing around with different key cap sizes and shapes for different noises and fun.

I printed everything in some basic silk pla just on my ender 3 as a test and it ended up working just fine. Printed with no supports and just 0.2 layer height and the overhangs weren't bad. Just need the main body and 2 of the pins (thumb parts), the bearing cover is optional but I liked it for a more even look.