The main focus on this instructable is the button itself. You will find attached a .stl file, that allows you to print out the buttons that i made.
I have an Ultimaker
3D printer, using Cura for slicing the files. If you already feel lost, that means you probably don't have a 3D printer. Don't worry. Maybe you will be inspired to get one. It's awesome!
So, the reason for using Cura for this product, it the possibility of pausing it midprint. Many 3D printers have this feature, the simple "pause" button, that stops and resumes the print. The advantage with using Cura is that you can actually pause it at a predefined moment, 4.5mm for my part, and actually have the extruder hotend (the part that melts the plastic filament) move away from your object! This way you are free to fiddle with the object, like putting LEDs into it.
For material i chose ABS, because it has better translucent abilities than PLA. Of course natural PLA would work, but I want it to be opaque, so the LEDs are invisible when turned of. Nylon would probably also do the trick. My settings were:
layer height: 0.1mm
Pause at print: 4.5mm
(for increased bridging quality, turn fan on 50% after inserting the LED.)