Steve,

The the equation that ThrustHP use has a fixed Ct which does not take into account pitch....this is not a very good reflextion of whats going on.(Thrust=Ct*q*rps^2*diam^4). Ct is set to .0888 no matter what the pitch. Actually, for most props, Ct range from .05 to around .12.
(see [link]http://naca.larc.nasa.gov/reports/1932/naca-report-378/[/link])

In reality, if you take the 75% blade angle of a prop it will roughly compare to the normal stall pattern of a wing. At around 10 degree absolute AOA the blade will start to stall at around 19 degrees the prop is pretty well stalled (but still generating thrust). Around 6 degree AOA is the most effeceint so I would recommend a prop with 7 to 10 degrees AOA at 75% of blade if you want the greatest static thrust and practical use for 3d.

If you want to find the Blade Angle at 75%:

Angle = acr tan(pitch/(2*pi * (.75*r))) or for pitch

Pitch= tan(angle)* 2 * pi * (.75*r)


steve