I modeled some thumb-sticks for my Xbox one controller for Lift off; a FPV drone simulator. It has a 3mm screw hole in the mounts so if you want to make your own thumb-stick all you have to is make a thread 3-4mm deep thread to interface it. I recommend to run a 3mm through the hole first to make it easier to screw in the piece. I also made a curved connector not in the picture
print the thumb stick upside down along with the mount with supports
The author hasn't provided the model origin yet.