Edited stuff in italics
Dave, I was a bit confused about what you meant by the relative mass and rpm. The only significant comparison between the two of which I'm aware is angular momentum. I think helicopter rotors have more angular momentum than the average gyroscope.
There are many other relationships that include mass and rpm. Rotational Kinetic Energy is one of the obvious ones. I didn't consider including more concepts to be useful.
As far as what type of non-relativistic rotational kinematics to use, drop the terms "gyroscopic" and "aerodynamic" and I'll agree with you.
The flapping hinge offset is described by basic physics quite easily. This is a very small part of the explanation. There are aerodynamic and control geometry effects that have a much larger effect on gamma. I alluded to this in my long post on gyroscopic precession. The natural frequency of the blade becomes less than the 1/rev of a blade with the flapping hinge coincident with the center of rotation. Because of this, the blade wants to flap in a full cycle in less time it turns through a complete revolution, so when it's finished a 1/4 cycle (max displacement) then blade has rotated less than 90 degrees (gamma less than 90).
Were it not for a driving force that is mechanically in phase to rotation of the blade (via swashplate) then the blade's motion could be quite erratic.
I live in Comox. I was in Vancouver two weeks ago, wondered if I should look you up. Two kids screaming in the back and then being rear ended by some greaseball who figured smoking cigarettes was more important than stopping at red lights reaffirmed my belief that although Vancouver is a fun, beautiful city, the best view of it is the one in the rear view mirror.
Matthew.
[ 20 November 2001: Message edited by: heedm ]