120mm case fan redirector

Description

I have a Tripp-Lite wall mounted network rack with a spot for 120mm intake fans on the bottom, but these blow air straight up, which immediately hits the first thing mounted in the rack and then spills out the front and sides of the rack. I designed this part to redirect the incoming air towards the back, where it can hopefully reach other components. 

It doesn't fasten to the fan, just sits in the top mounting holes. The spec for case fan mounting holes is 4.6mm, but probably varies a bit, so I posted two STLs, the first one has 0.25mm of clearance for the posts in the mounting holes, the more clearance STL has 0.50mm of clearance. The original one is a snug fit on the fans I have and keeps the part in place even when upside down. 

Printing

If you print with the front opening facing down, you'll need minimal supports that will detach easily and not mark up the inner surface very much. You will probably need a brim. a 5mm external brim worked for me. See the uploaded picture from my slicer. 

I used PLA, 0.4 nozzle, 0.2 layer height, 3 perimeters, and 13% infill. The top shell is thin so there is very little infill regardless of settings, it but seems strong enough. You may see the infill pattern show through.