Counter Rotating Windmill

This design contains two coaxial counter rotating toroidal propeller one within other. It looks mesmerizing when both turns. This is %100 printed version. I strongly recommend bearing version for smoother rotation. You can see design here. ASSEMBLYIt's very easy to assemble.Take the Hub (orange)Put outer propeller as shown (yellow)One washer (grey) (not push too back so propeller can rotate freely)Now inner propeller (purple)One more washer (same as before)Sun on the hexagon socket (yellow)