Wind Power features heavily among the energy alternatives we use in our off-grid home in Texas (for full information, please check out Off Grid in Texas).
For our first wind power setup we stuck with what was readily available.
For the turbine blades we chose the famous PVC blades made popular by Vela Creations. The blades are three 30" (76.2 cm) mounted to a used tile saw blade for the hub.
We used the larger 50 volt Ametek motor, but alternative generators could be made from a treadmill motor, a winch motor, or ideally a permanent magnet alternator (PMA).
Tail or Rudder
For a tail we used a piece of 1/2" (120 mm) plywood mounted to 1/2" (120 mm) steel pipe. There is no need to be fancy here (though you can if you like); your goal is to keep the blades facing into the wind and balance the generator on the other end.
The above mentioned items come together and are attached to some kind of mount, which allows wind turbine to pivot into the wind. This can be purchased commercially or made yourself. Ours was used and made in someone else's workshop, and we purchased it on eBay.
For a tower we decided to get creative with PVC. We used two 4"X10' [101.1 mm X 3 M] lengths connected with a coupling.
The base of the tower is hinged with a piece of 1/2" [120 mm] steel pipe that runs through the PVC perpendicularly. This piece of pipe is then attached to two elbows which are connected to two pieces of 18" [45.72 cm] steel pipe which we set in cement.
The electricity generated by the Ametek needs a way of getting to the batteries. For this we used an old 16 gauge extension cord cut at a length of 30'. 16 gauge wire is close to the minimum you want to use, and there are a number of "wire gauge calculators" available online.
Slip Ring or Swivel
For this wind setup we did not use a slip ring, instead we simply left some slack wire in the tower twist. As many others have found, the wind turbine tends to turn 180 degrees clockwise and then 180 degrees counter clockwise, thus twisting and untwisting the wire evenly. You may need to eventually untwist the wire manually, but we did not have any problems.
Controller/dump load or diode
For our modest wind power generator we did not bother with a dump load for the excess power. We did use a necessary diode, which is required for our former-motor-turned-generator. Our diode is a 20 amp rated blocking diode.
Just like our woodgas projects, our turbines are largely be made out of reclaimed or easy-to-find components.