I decided to do a little playing around. Made a set of 3" diameter PVC pipe blades.
Was quite disappointed in thier performance, even though they were only rough cut and unbalanced.
So decided to try cutting another set with a little more precision. Took 10 minutes to make them instead of 5, so they're still pretty much crap. Still disappointed in thier performance. Didn't feel like they'd have much in the way of torque and the RPM's delivered were miserably slow. Somewhere around 100-120 RPM in a stiff breeze (I'd guess around 20mph.
Then I decided to throw both sets on and see what it would do.
All I can say is WOW!! That sucker SCREAMED up to around I'd guess 600-700 RPM (had around 30+ blades passing my head per second) and I could feel the torque would be enough to knock me senseless if a blade clubbed me in the noggin!! (Was holding the bearing in my hand!!)
So next I'm going to try and find a slightly longer 4" diameter piece of pipe and cut 3 sets out for a total of 6 blades, do a more proffessional job of cutting and balancing them, and see what they will do.
With the junky system I've got right now I'd be willing to bet that the 20mph wind outside (according to weatherbug.com) would have no problem starting my chainsaw up if I connected it to the flywheel on it!! :O
