I wanted to have a fan for PLA printing and had a 50mm fan laying around. So I designed myself a fan mount for my TEVO Tarantula. v8 now has a sideways shield, v7 has not. v10 is improved and has reduced complexity
fan_mount_experimental.stl is my attempt to make an enclosure for the fan and it hasn't been tested yet.
fan_mount_top.stl is another version and it hasn't been tested either, but it should work.
You should put a washer between nozzle fan and the fan mount to prevent the nozzle fan from rubbing against the fan mount.
This thing was made with Tinkercad.
Mount onto the lower screws of the nozzle fan. I used M4 bolts and nuts to mount it onto the 50mm fan. Make sure the blades don't interfere with the mount. A well calibrated printer is a must.