( UNDER CONSTRUCTION )
Some time ago, I searched the web looking for an "easy to make" wind turbine. I didn't want a complex turbine, but neither I wanted a turbine of the kind "buy this kit, and glue the parts".
I simply wanted a turbine which I could make all by myself, without any advanced feature (no need to produce even the slightest amount of electricity, for example ). Something that I could use just for learning the principles behind wind energy.
For understanding wind turbines, you have to know various physical concepts: inertia, momentum of inertia, torque, force, momentum of a force, and their cross-dependences. I belive it is easier to understand these concepts if you have a simple wind turbine and with replaceble blades, each set of blades having different properties.
Unfortunately, I wasn't able to find something that suited my expectations. I can't work wood, metal or plastic, and most D.I.Y. wind turbines require some work with those materials, and neither, as I said, I did want to buy pieces to simply glue together.I wanted something to make with my hands.
So designed a small, simple turbine to make with the only material that I'm able to work with: paper !
I tried various configuration, and at last I found one model that suits me.
You need: a printed copy of the drawings I made ( rotor.pdf, tower.pdf, blades1.pdf, and optionally blades2.pdf ), some sheets of light cardboard , shissors, paperclips, one toothpick and glue.
To make the rotor, cut the pices from the paper sheet on which you printed the file rotor.pdf. Fix them to the curdboard with some paperclips, then cut the cardboard. Join and glue the pieces together following the instructions on rotor.pdf. The lightly shaded zones on the drawings are the one to glue. If you want, put a little square of scotch tape on the dark shaded zone of the rotor. Then put another small square of tape on the dark shaded zones of the blades. This way, when you put the blades in the rotor, if they are too loose, you can join the two squares with another piece of scotch tape.
The second step is to make the tower, following the instructions on tower.pdf. You probably will have to use some extra cardboard to strenghten the tower, gluing it on the weak points of the tower. Particular care is needed with the top roll, the one in wich you will put the rotor. If you make a roll too tigh, the rotor won't spin. If you make it too loose, it will lean and the blades will touch the tower. The better thing to do is making more rolls and choosing the best one with some tries.
For the last step, cut the blades from blades1.pdf, fix them with paperclips on the curdboard, and cut three copies for each blade. If you want, you can do the same with blades2.pdf. This way you have a variety of blades to try.
The simpliest way to try the wind turbine, is grabbing it with one hand, put your arm in front of you and walk at a costant pace. Look wich blades starts to spin at a lower speed. Look which one spins the faster. Experiment with the various blades.