Well my first attempt was a small Zub Woofer blade just to see if it would go round (
see here).
The blades were mounted on a 10mm bolt which ran through a bracket. Not surprisingly that was a pretty noisy 'bearing' and it rattled and groaned. I took it all down before the neighbours complained!
I decided that I needed a suitable bearing. Smaller than a car hub as I am trying to build a smaller system than the Hugh Pigott systems. Anyway I found myself at the dump one weekend (as you do) and guess what kids... Dad's bought a new bike!
However Dad also has an angle grinder.
Now reduced to this much I was left with a sound bearing and a nice flat chain ring onto which I could mount things.
I also retained the headset as it might make a good yaw bearing or furling tail bearing.
I also scrounged a small tapering, plastic bin for the chop.
This evening I decided to bolt it all together as it was a breezy night and it made a surprisingly nice looking rotor.
I retained part of the rim of the bin to provide support at the root of the blade.
I stuck the rotor onto a totally unsuitable piece of 1" by 3/4" baton and hoisted it into the wind. To my surprise it really flew. The only problem was that the blades do flex in strong gusts and were striking the wooden support. When it is remounted in service there will be a small axial PMG between the chainring and the rotor which should provide enough clearance.
This has taught me quite a bit this evening. I was quite taken aback by how much power was developed by a small rotor made from junk. It makes the larger systems flown by some of you guys seem quite scary.
