"what length should the 2x4 be" ....as long as you want 3-4 foot or so
"where can i find some howtos on carving blades" scoraig wind in goolge will find hugh's site very good stuff on blade carving.step by step.
My first attempt at balde carving was with a forklift pallet. Ripped off 3 radiata pine 4 x 1's and built a basic blade simple taper simple twist simple result.
Dont be deterred by how "exacting a science" it can be made to look. The wind is very very forgiving, and provided it looks vaugley like a blade with some kind of profile, it will spin in the wind. .. even three boards un carved and bolted to a hub with an offset to the plane of rotation will turn. You can make it as complicated or as simple as you wish, the main thing is to get some carving under your belt and see some reward for it.
The worse the first practice blades are, the more room for improvement there will be for the next set. after the first set, you will have learned enough to have a "real go" at the second lot.....and then the third....and just an improvement here, a little bit different there, a higher tsr this time......and suddenly, it's fun, and not hard at all.
do not panic that your wood is too thin (if you use 4 x 1). The figues will require the uses of thick timber near the hub end of the blade. Ignore this and use up what thickness you have, as the inner third of the blade may just as well not exist for practice purposes. At least try and get the outer (tip) third as close as you can to the figures . The performance will hardly notice that the inner third is nowhere near exact.
Remember this is for getting the skills for the bigguns that come later ( with the expensive thicker timber).The first set i carved from 4 x 1 were 4' long each. looked fairly skinny for any power.... big big wrong... When I took them out into the wind ( it was pretty gentle at that stage) I had the hub just with a hole in it with a screwdriver poking out, and me holding it.......big mistake. I hand spun it, walked around the corner into a gust, and it roared into a life of its own...scarred the hell out of me . It ran from a hand spun idle up to (well it seemed like a million miles an hour) well over 500 rpm in a split second., and with a roar I will never forget. So although they dont feel like they have any purchase on the wind like you may expect, once they get running and develop the lift, they take on a life of their own... like a runnaway train...so be warned.
there's nothing quite like watching youe own blades turning, especially when you made em out of an old pallet, or something else just as useless.
...........oztules
