Made the Gear_Knob for my Wife.
Made it for a 9mm Pipe for through the middle and the 2 ends so that it can hold up to a bit more.
put a 9mm pipe through the middle, it must be a bit longer than than all the parts put together. Fit a screw (I used M6) through it all and fix it with a nut, use discs.
The end for the Gearstick on the pic broke ... my wife is kinda hard on the stick I learned :cD

Prusa

i3 MK3

Yes

No

0,1mm

Doesn't matter