Here is a Minigun concept what I made for the TV series Halo. Master Chief used this Hero gun in the first episode and you also can see it in the trailer of the seires.
I had to do a 2D concept art and 3D parts for 3D printing. We used for base an airsoft getling gun and we add a custom hull what we printed out.
This concept based on Eva Kedves's 2D concept art.