Spacewalker first attempt.
I just did the math 380 rpm on a 80" rotor puts the tips at 90 mph, 1140 rpm gets you 271 mph. I'm getting nervous!
BTW, I changed the tiltback from 12*, (tried for 10*, but got 12* somehow.), to 7*. Now I wish I had maded it even less, too little seems to give you an RC car, too much a pile of balsa, just right an autogyro? I'm starting to feel like Goldylocks.