Goal: build a Savonius wind turbine made out of cardboard to see what
works. This is for the turbine only and not the generator itself. The main photo you see is the goal.
The need for a working model grew out of frustration trying to
jury-rig various designs of a Savonius turbine that in the end would
not turn at all in the wind.
Some Initial Botched Designs
Shown below are several botched designs. All four are attached to the drive shaft of a 24-volt DC battery-operated lawn mower. The vertical bar you see is an allthread bar that is attached to the motor shaft. The galvanized metal is half of a dryer vent tube. The first design would turn half way and then stop because of the resistance of the back side of it coming into the wind. I then added a top disk and attached a number of 2-liter soda bottles and some 1-gallon milk jugs to a disk on top. With a stong wind I actually got the mill to spin if I gave it a start. It has to be the ugliest windmill ever.
The second design is all cardboard and looked really sharp. it didn't budge an inch in a very strong wind.
In the third one I added parts of the dryer vent tube to the cardboard mill and that worked a little bit but there was resistance on the back side coming into the wind.
At this point, I decided that I had to go back to the drawing board with a simple model to see what had a chance of working.
Step 1: Materials needed
The following project took me one hour from conception to finish and I
was making design decisions as I went along. I was amazed that it
worked perfectly. I guess it should work perfectly because it is the
design described in a number places. Of course, the coffee can and
soda bottle designs were said to work but didn't for me.
a. A large piece of heavy-duty cardboard box
b. 14-inch dowel (or knitting needle, or something similar) to serve as an axis rod
c. 2 small rubber bands
d. Duct tape or electrical tape
e. Hot glue (optional)
What you see in the photograph are the pieces you are going to cut out of the cardboard. You can also see the knitting needle with some rubber bands on it.