A friend's controller had been used enough that the soft cap had worn off of the control stick, so I made this. Worked so far and everyone seems to want one, so now everyone can have one! Enjoy.

First off, this is to replace the rubber, not cover it. If you do not fully remove the old cap, this will not fit.

Use some flexible filament, I used NinjaFlex. I used an extruder temp of 222 C with no heated bed or fan. The most difficult part of this design is the bridging, which does not need to be perfect. Although be sure to cut out or pull out any stray extrusion from inside the cap.
It is intentionally a tight fit, start on one side and work your way around. I personally used my fingernail to catch the lips on the top and stretch it over. Whatever works!