Simple universal joints designed for use in my RC racer project, but I have provided versions for 5mm to 10mm shafts, which should make them useful for all sorts of projects.
The cross shafts are M2x8mm screws but you could probably get away with stubs of 1.75mm filament for low torque applications.
See it in action here: https://www.youtube.com/watch?v=Wd1GOG41lfk