Anyone who sells those sorts of blades as some kind of 'improvement' for the Air X or the 403 is wrong in my opinion- they're just too large and they'll run more slowly.
Looks like they compensated for that by using a very high TSR. But that means virtually no starting torque from the bulk of the blade - it all comes from the fat secton near the hub, which has little leverage. If you have even a small amount of static imbalance and friction it probably won't start.
The low torque continues until the blade is up to speed and the lift kicks in - which means if it's still in stall at cutin and the turbine has enough static imbalance and friction it will probably stop again even if you motor it up.
The high TSR also means a slight error in the angle of the blade along the blade's own axis has an enormous effect on the angle of attack, and thus the TSR.
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Segit: Did you make your own hub? Is it strong and flat, so the blades angle around the axis of their length is correct? Did you check the static balance? (Even a very small error from 120 degrees in the blade's plane will cause a static imbalance.)
With this low starting torque and a high TSR on thin blades making stall continue almost to dead-on-at-TSR spin, static imbalance is not just a vibration problem. It also acts as cogging.
When you motor it up and then disconnect the diode bypass does it stop in some arbitrary position, or does it always stop in the same position? If it's always in the same position, does it gradually slow down and stop, maybe moving a tad backward right at the end, or does it brake down and stop quickly, with no backup at the end and maybe with a jerkiness as it stops?
I'd pull it down and check a couple things:
- Static balance will have to be dead-on with these blades. Spin it by hand (in a location with no wind, like inside a garage) and see that it stops in several different positions. (With cogging it will have several "favorites" evenly spaced around the circle. But it should pick all of them with equal frequency.)
- Test for friction by spinning it up to a high speed with your finger.
- Test again by pushing hard on the prop (to model wind drag) and turning it through a full turn, to see if something is rubbing under load.
With that low starting torque this turbine will also have to track the wind very well. A small error in tracking direction might make the section near the hub have a selective drag (due to the blade roots on top and bottom presenting different cross-sections to the side wind) that produces a torque which counters the airscrew torque and leaves you with nothing to start the blades, or even a braking effect that stops them.
To get it to track correctly you'll need to get that tower essentially vertical and get the center of gravity onto the yaw axis so any residual error in tower angle doesn't foul you.
