After designing the frame for the Galaxy S9 I also acquired an S9+ and made this one. The S9+ has an even better fit for the GameSir X2, since its size is more maxed out.
(See the design for the S9: https://www.printables.com/de/model/757875-gamesir-x2-frame-for-samsung-galaxy-s9)
3 pieces that are easy to print with the flat side down.
The thin one is rather optional and only fills a small gap.
It can be easily glued to the front frame.
The back piece can be clipped on and serves two purposes. It closes the rather big gap at the back and it keeps the GameSir opened at the right width for the Galaxy S9+.
This revision features two small protrusions on the front frame that fit into the rubber gaps of the GameSir (see foto). This helps keeping the phone in place - very well actually. Also the phone snaps well into place in the frame, which makes a good compromise between tightness and snapping it in and out.
The pieces in the pictures were sliced with Cura 5.5.0.
0.6mm Nozzle, 0.28mm layer height, material: PLA
The author marked this model as their own original creation.