This is a slide on cover/case for the OnePlus X Onyx. The idea is to provide look & feel for the virtual keypad of Gameboy emulators on a mobile phone. In my case the OnePlus X Onyx (with the original phone case/back cover) and the "My OldBoy!" emulator. Without the haptic of a keypad I kept "loosing" the virtual control buttons and D-pad, which made it almost impossible to play.
Glue the top and the bottom parts together. I used "UHU - Plast Poly Cement" for PLA. (I did not find a way to print it in one part with a satisfying result).
You might want to sand the part a little bit, to get smooth surfaces and edges.
You also have to arrange the virtual keypad layout, so they will line up with the printed "buttons". It might help to increase the display brightness to maximum. By doing that, you can see the control elements through the cover.
You can try to make it fit to other phones by scaling X/Y and Z. Feel free to remix!