Hi Guys. New here. Re: making blades, I was IN the wind business in the 70's-80's. Started out by buying a set of blades and governor and building my own 4KW machine. I had access to a machine, to get measurements and photos, so, my job was easier.
Wooden blades won't flex a lot if built correctly. They should taper from the hub end to the tip, slightly. Make them like an airplane wing profile, and narrowing about 1½" from the hub to the tip.
For example, if you have a 2 X 6 piece of wood, you start about 4" from one end, and cut the angle of the FACE of the blade, from the leading (face) edge of the 2" TO the trailing (back face) of the blade. This gives the correct angle. Then, you remove the "Back" wood to achieve the airfoil shape. You also remove about ½" from the leading edge starting about 2/3 of the way to the tip, TO the tip. Remove the 1" from the trailing edge at about 2/3 of the way to the tip, TO the tip. This will give a taper look to the board. The profile is shaped the same, all the way to the tip, it just slowly tapers, so you have a nice wing shape.
It's easier to do than explain.
The Bergey machines that I sold, use a composite blade. It looks similar to the PVC pipe shape, but, you need to fasten a block at the hub end, both front and back, to achieve a FLAT place to bolt the blades tight. If not, vibration WILL happen and the bolts will loosen or the PVC WILL shatter. Trust me, I've seen it all.
On the photos of the PVC blade setup, that was at the beginning of this thread, the mounting will not last long, under load. Best way to mount the blades, is, make a 3/8 thick plate and bolt THAT to the hub. Bolt the blades to that plate. Use fine threads and loctite. That is where the blocks come into play, that I described. Make the blocks fit the PVC exactly, and use 4 bolts per blade. Orient the blades so you have the face of the blades a little less angle than shown in that photo. You want the blade setup, to start to turn around 7-8 MPH wind. Generator should kick in around 9 MPH. Output will be very low at that speed.
The Bergey blades have a "Twister" device rivited to the leading edge. It has a Bullet shaped weight protruding out, ahead of the blade, and at high RPM, around 1500 or so, it will help twist the blades a little, and cause the machine to start to Yaw out of the wind. I would guess those weights to be around 1 pound Never weighed one, but, you could feel the weight. THIS IS NECESSARY to keep from having a runaway in higher wind speeds, above 40 MPH. There is a neat way to construct the tail, also. It will auto furl and straighten back out automatically.
Then, there is the slip ring to configure. Enjoy the project, and I will try to offer advice. Please don't think I know it all, but, I have been into it pretty deeply.