I made this to extract fumes when soldering. Two sizes are provided, for 80mm fans and 120mm fans. There are holes in the legs to install switch if you like. The thickness is setup for a typical fan depth + a 2mm fan guard, so 28mm total depth. I've provided the step file if you want to modify it to fit your needs.
This is the fan guard I used: https://www.printables.com/model/147071-80mm-fan-guard
I printed bolts & nuts to hold it together, but it turned out to be a real pain to get them sized so they tightened correctly. You could use regular metal hardware, zip ties, or glue.
The author marked this model as their own original creation.