Simple fan cover, bulges outwards with lots of little holes, for that wonderful infested look.
The holes (apart from the screw holes, obviously) are deliberately off centre; I figured I'd mention that because it might bother some people.
V2 added, which has cutouts allowing for cable routing around the grille. I had to scale down to 38mm to line up with the screw holes.

Please check out this model for BL-Touch support: BL-Touch Mount
I really like the SMOOTH FANG since it is well made and can be printed without supports, but I was unable to find a mount for my Ender 3 that I liked and that had compatibility with my EZABL.  I also did not like how many mounts required a separate 40mm fan duct.  Also, I really prefer to print without supports.  
I created a mount for the smooth fang that is compatible with the Ender3, has compatibility with the EZABL, and has a built-in 40mm fan duct.  This ENTIRE cooling duct assembly can be printed with NO SUPPORTS!  I made this as simple as possible, without comprising build strength.
Please leave any requests/suggestions in the comments.  I will attempt them as best as I can if I have the time.
SEE PICTURES ABOVE FOR INSTALLATION PROCESS.
NOTE: I have only installed and tested the "CUSTOM-DUCT__ABL.stl"  please let me know if I need to modify the other files.

This is an Aperture Science style fan cover, generated using a modified version of the Customizable Fan Grill Cover OpenSCAD script to better match the original logo design when mounted with the bottom side facing forward (to allow for a smooth surface finish when printed on a glass bed).
I designed it to match the stock 4010 fan of an Ender 3, but it should fit any 40mm fan. Overall thickness is 2mm, prints in minutes without support.

yet another grill for 4010 fans
4 Screws M3x15mm required

In this video, we look at the features of 3d-thread modeling for subsequent printing on a 3D printer. For the simulation will use SolidWorks and Fusion 360. ...