Improved FLSUN V400 Fan shroud

This is a fan cover for the FLSUN v400 that is a bit further from the fan (+4mm) and should reduce a bit of the noise. 

Modified the file to add more structural support to the side-pins and also added a few more slots to enhance airflow. 

Print: Print at 0.2 layer and 30% gyroid infill.

Multicolor: Print it facing downwards and add a M600 (filament change) on layer 4 or 5 to do a multicolor print. 

Edit: I have added a sliced gcode for the v400 that does the filament change pause and prints it perfectly. (remember to load your default bed mesh in your start print macro)