Well my PS4 controller stick rubber had worn off and it was time to make a better one. I designed this analog stick extension as large as possible to get a comfortable feel.
The bottom part is 3d printed and goes together with a single 2,2mm diameter screw. So no need for glue here.
The top part is made from two component molding silicone, but any similar rubber or silicone substance can be used. Mold consists of 2 parts that go together to form the whole. It might be nessesary to drill a hole in the top to be able to pour silicone in. You can also fill two parts seperately and then squeeze them together. Beware of the air bubbles when pouring.

The design of the parts is still work in progress, but first test prints have been made. Let me know if there are any suggestions!
https://youtu.be/utsR01IrCB4