Wind driven prayer wheel

thingiverse

https://youtu.be/NYXPqTRUikQ 8-7-2015 Finally struggled through these prints with my old prusa i3. I had to use some hot glue patches where the print came out wrong. Anyway the first one works. http://youtu.be/Ow18Z0k05fY In Tibet and Nepal you can see holy people spinning wheels similar to this. The theory is that with every rotation the prayers of compassion, that are written on the side, will go out to the world. Some prayer wheels are situated over a stream, and driven by water. This design is based on an efficient Darrieus wind turbine, from 1931. I used the standard 60 degree helical swirl for stability. The blade has a profile plotted around circumference, instead of being symmetrical. This non-symmetrical blade profile gives more efficiency and easier self starts. I wanted a design that would spin in the lightest wind, with the absolute minimum resistance. I tried various planetary gear mechanisms. The result was too much friction, and the wheel couldn't keep spinning when the wind died. The only way I could get the blades to spin in low wind was with a simple spacer between the wheel and the blade holding mechanism. This allows for the power to be transferred to the wheel through a small amount of friction. This also allows for continued rotation after the wind dies. In higher wind conditions you can switch the disk under the wheel, to increase the friction. The wheel and the wind turbine use four R4ZZ bearings, for the smoothest spin. Traditional prayer wheels have rolled up prayers inserted into them when they are made. This design has two hollow capsules in the wheel. You can pause the print, insert your prayers, and continue the print, to seal the prayers in forever. The Dalai Lama says that electric prayer wheels only benefit the electric company.