Sparweb - I'm fairly confident the blades will hold together. I watched it spin completely unloaded in some 30-40 mph wind gusts and I'm pretty sure it was north of 6,000 rpm. They are really, really light weight and small in cross section. I'm certainly not going to stand next to it though at those speeds. Once the generator is hooked up, it spins much slower.
The clutch is for the 7' Christmas windmill. It's still not back up due to the cold conditions and feet of lake effect snow preventing me to drive a 4-wheeler back to the tower.
I did some super heavy Excel work that I've been dreaming up in my head for a few years. I wanted to exactly predict the RPM of the blade by knowing it's CP vs. TSR curve and the generator power vs. RPM curve. About 4 hours later, I finally got it working and it works quite well. It show the compounding effects of the squared power rise of the generator fighting the cubic power of the blades vs. wind speed, while obeying the TSR efficiency curve.
The values here are my best guess for how the Mini CNC blades were performing on it's original outing. I'll have to plug in my new numbers for the tighter air-gap + better wiring curve for the alternator. It sure looks like I'm not at the top of the CP curve, so making the air gap bigger might help a lot as well. I was hoping to lower the cut-in speed, so I'll have to try both.
Ignore the choppiness of the power curve. The way I calculated it has discrete values and it will drop a value if the numbers don't match up very well.... the real power should be the imaginary curve at the very peaks of the points.
I also chopped off the RPM plot.