Hovercraft propeller, 3 and 6 fan blade versions.
Print with brim if your bed adhesion isn't good. Blades are slim but they don't require support.
See video here https://www.instagram.com/p/CLLfBjojF5o/
Update: Added curvy wider version with 3 fans. Mode air flow and direction is reversed.
Update: Added a mini propeller, builds like vase mode, 2 perimeters, no infill for blades, assuming 0.4mm FDM printer nozzle. Costs quarter gram of filament and builds in 3 minutes excluding heat time. https://www.instagram.com/p/CLicpaGDJpR/
Update: Added a quadcopter like blade, not easy to print, you need suppors, point blade tips to build plate and turn on supports https://www.instagram.com/p/CLioNK7jRfW/