Idea from https://www.thingiverse.com/thing:839620 but it's a totally new design.
Reuse original E3D v6 fan dust. Place the fan nearly vertically to save space and avoid hitting towers on Kossel Mini printer.
You need M3 x 12mm or 14mm screw to fix the fan. Too long or too short doesn't work. Or you can adjust
fan_fixer_d in scad model to fit the length of screws you have.
bolt_pillar_lenght to fit the screws which are used to fix original E3D v6 fan dust.