Tevo Tarantula 120mm print cooling fan mount

#### Description
This is a 120mm fan holder to be coupled to one of the vertical side rails on a TEVO Tarantula 3D printer.

#### Dimensions
Fan size: 1x 120mm
Fan holes: 2x M3
Frame holes: 2x M4

#### Functional description
The fan is used for post-print cooling. In my case it is connected to the MKS board (on pin 66) through one NPN transistor. No changes are needed in the firmware.
While printing PLA, making the bed rapidly reaching 35'C makes the object pop out of the bed without a