This is a 1U rackmount fan tray designed to house upto 120mm x 25mm fans in an effort to cool rack units above (or below depending on orientation). Regular fan screws are enough to secure the fans. They will bite into the plastic, and then into the fan. It can be a bit tricky to get the first one in, but after that it was ok.

It is designed in 3 parts, all printable on an Ender 3, which snap together, so completely toolless!

My purpose for this was to cool a Ubiquiti US-8-150W switch (which isn't designed to be rackmounted). With this design, and a couple of Noctua NF-F12 (5v), I was able to drop 12 degrees celsius! The fans suck in the hot air from above, and exhaust it out the back.

I'm not an aerodyanmic engineer, so the design could likely be improved, but it serves me well enough.

Printing

You will require all 3 parts.
All parts should be printed vertically - This reduces the need for supports, and also means the tolerances for the middle piece should always be met.
The middle piece requires some small supports for the arms, but only so that they do not sag when printing. Both sides pieces do not need supports.

As the part should not be taking any abuse, a light infill is sufficient - I used 20%.

Note that for Ender 3 users like me, you must disable the Skirt under Built Plate Adhesion in Cura in order to utilise the full bed size.

Creality

Ender 3

No

Yes

0.2mm

20