This is a remix of Demosth's excellent Skirt Fan Mount. I found the stock fan mount to be flimsy and easy to break off the extrusion. Demosth's version is a lot better but still only uses a single screw. I also wanted to use my red fan grills for extra flair.

I added three additional features:

• 4 more holes to secure the mount to the extrusion any way you want (if using the outer most holes, you'll need to attach the mount to the extrusion first before attaching the fans and grills). You can still only use a single screw to mount it on the extrusion if you're feeling lucky, but I recommend using at least two.
• 3mm through holes to allow using custom fan grills (just as on the stock fan mount, you'll need to add heat inserts to the fans).
• Side profile for a snug and elegant fit against the part A and B side skirts, adds to the overal sturdiness of the assembly.

This version is provided in 3 variants:

• Solid_Skirt_Fan_Mount_Channel: with profile walls and cable channel 
• Solid_Skirt_Fan_Mount: with profile walls, no cable channel
• Solid_Skirt_Fan_Mount_Open: without profile walls on the side. (no idea why you'd want this one) 

All models are watertight and print as normal. No supports needed.