"El Enrrabadore-mor" wrote in message


Euler's equation of motion cannot solve the
problem, nor it seams to work for a sphere.
If the gyroscopic mass is a sphere, all its
mass inertia moments are equal and you
end up with nothing.
Physically, the result for a sphere will be that
a sphere won't precess, contrary to evidence.

Why would you say that? The necessary torque to
result in a precession can be about the sphere's
center of mass, and a gravitational field can
provide that for a sphere spinning on a mount
attached to one of its poles -- such a mount is
not coincident with the center of mass.

The Earth is another matter, since it is not
a perfect sphere -- the equatorial bulge
provides a "handle" for torques.