This is a customized design for the Fairphone 3 Bumper.

You can clip in a back plate with your own design. A blank one is included.

I also upload more back plates, so don't forget to check out my latest ones (-;

Print instructions

I tried the Bumper with ninja flex and ninja tec cheetah. Both works out fine, but bumpers made of ninja flex will get a bit loose after some time.
Use a 0,4mm nozzle.

The back plate is made of PLA. This part is more difficult than the bumper. There is a small edge, with holds the plate in the Bumper. These tend to break after some time, when they are not printed right.
Use the “allow single extrusion walls” feature in Simplify 3d, or a similar feature in another slicer and set the temperature about 15°C higher for the last layers.
Try this with the blank back plate, before investing a lot of time in a more complex one.