120mm PC fan aerodynamic spacers

As the original, this remix is inspired by: Stealing Noctua's quiet airflow mod

Compared to original design, this is more aerodynamic and optimized for radiators. Use auto-orient to get better face on the print bed if you're not sure.

I use M4 bolts just because I drilled and tapped my radiators into that size as getting proper bolts was a nightmare for me. Because of that, fan holes need some persuasion under an angle with 4mm drill so the bolts can fit inbetween the fan mounting fins. Should you use M3 bolts instead or different setup, fan drilling might not be needed.