First, I want to thank Lukie80 for this nice case for the GT2560.
The bracket fits to his model:https://www.thingiverse.com/thing:1279978/#files
I have built a Raspberry 3 case in CAD to match the Hexagon design. In addition, I have built a bracket that can be attached to the GT2560 housing. For the raspberry b+ you have to download the "raspberry_cover_b+" . I hope you like my work, if so leave a comment or a Like.
First, you need to attach the bracket to the fan with two screws (see picture 1). After that, all you need to do is attach the Raspberry to the case with four screws (see picture 2). Plug everything in and start.