Lenz2 helical turbine

This is a helical version of Ed Lenz' Lenz2 turbine blade. His homepage is here http://www.windstuffnow.com/main/lenz2_turbine.htm Dimensions: this should give a 120mm diameter, 160mm height windmill. 2013-06-09: Hey look, I made a larger one - http://www.thingiverse.com/thing:99132 31-5-2013: I managed to print the last layer last week and the turbine is now spinning in the wind. I started thinking about making a larger version of this that i can still print on the 200mm print bed. The larger version that i am working on is going to be mounted on a electric bicycle brushless 3 phase hub motor of about 200 Watts. It will also use aluminium arms (20×2mm flat) instead of the plastic ones. The new thing id will follow later. 18-05-2013: Crud, broke the pulley on my 3D printer, posted the picture of it on a wooden stick on the back of my shed. It only has 2 layers now, 3rd one later when I fix the printer. 18-05-2013: Just uploaded a double bearing holder so I can mount it on a 44x44mm wooden pole. The bearings I am using have a 32mm outer diameter. They are not really the correct size for a 12cm diameter windmill. I'm planning a larger one for later. The bearing holder doesn't print very well, word of caution. I've also reuploaded the single blades for 30 and 40 degrees which now have a 1 degree resolution. Same thing, looks nicer, takes longer to slice. Also turns out you can print 3 single blades and a hub on a single 20x20 bed. When printing on scale 1:1 you can apparently print these without support which makes them look a lot prettier. Printing a single blade at 0.3mm height takes about 1 hour 45 minutes here. Printing 3 at once with hub is about 4 hours. Seems like a good deal. 16-05-2013: Uploaded a hex center hub to mount the single blades on. I'll probably add a hex nut cage on it for easier assembly. Perhaps nut cages on the blade mounting hole would make sense too. 15-05-2013: I just uploaded a new single blade with mountin