Based on Lukass‘s idea, i’ve redesigned from scratch the whole thing.

https://www.thingiverse.com/thing:2872736 

How it looks:

Curves are based on Pappus'spiral

(take a look here: https://mathcurve.com/courbes3d.gb/spiraleconic/pappus.shtml )

Windmill parts are designed to fit in a Sovol SV06+ volume. ( 300 x 300 x 340 mm)

I've used PETG for all the printed parts

BOM:
(color in the renders)

•  (red) 1x supporto_centrale 
  .2mm layer height
  3 walls
  25% gyroid infill
  
  Insert a 608zz here. press-fit location.
   
• (violet) 1x supporto_fronte
  .2mm layer height
  3 walls
  25% gyroid infill
   
• (yellow) 1x supporto_retro
  .2mm layer height
  3 walls
  25% gyroid infill
   
• (blue) 1x mary
  .2mm layer height
  2 walls and .6mm line width (to speed up print)
  5% gyroid infill
  Lock in place with a couple of zip tie.
  
  At layer 6 i've change filament color FYI.
   
• (green) 1x mighty_archy
  .2mm layer height
  5% gyroid infill
  2 walls & .6mm inner wall line width (to speed up print)
  Brim & custom support needed. Take a look at pic 5.
  I've print at 80mm/s walls & 150mm/s infill
  
  Had to insert 2 608zz here (top & bottom). snug fitting. if you're in trouble, try to warm a tad the PETG
   
• (black) 6x self-locking M8 hex nut
  Used self-locking nuts, so I didn't have to worry about loosening over time
   
• (brown) 3x 608zz bearing
  Better than plain 608 due to its sealing
   
• (silver) 2x M8 threaded rod
  The orizontal one is 45 cm long
   
• (orange) 2x M8x10cm hex bolt

I also drew a couple of bottom supports. if you wish, add a couple of hex nut to the BOM and enjoy yourselves :-)