This assembly is a combination of a slim case for the pi camera and a few mounting details that makes it possible to mount the camera at virtually any angle.
The two arms called mount2 and mount2r are right and left variants of the upper mounting arm. You will only need one of them.
In the picture the fixture is mounted using mount3 or mount4. These are specialized click mounts for the Velleman K8200/3Drag, If you do not intend to mount the camera on a K8200 you can mount the fixture in any m3 hole that is 2-3mm deep.
Standard Allen M3 bolts should be used for best result.
The parts are made to be printed with relative good resolution. I used 0.2mm which worked well for me. The holes are specified so that M3 bolts should be a very tight fit to provide a stable mount. It should not be possible to just drop the bolts in. You should have to screw them into the holes.
This is a remix from my camera case for the Raspberry Pi Camera module with mounting holes. It can be found separately here: http://www.thingiverse.com/thing:533865