Origin of gyroscopic precession

[GRB 080319B]

Is precession caused by uneven mass distribution in the gyroscope, or by an uneven supporting surface, causing a couple to form (i.e., normal force and gravitation force start to have non-zero cross products)? Is precession analogous to circular motion, the angular momentum vector is having its direction changed by the applied torqued in precession as the linear momentum vector has its direction changed by the centripetal force? As the angular momentum is decreased through friction, the gyroscope can't maintain precession rotation at that radius and translates downward (falls) in a spiral fashion. Is this analogous to the common circular motion experiment with a mass being rotated around a hollow tube by the gravitational force of a stopper, and when you stop rotating, friction reduces the linear speed of the mass, and the mass falls (spirals) into the center because the force is constant, so the radius of rotation must decrease. Is the gyroscope following an orbit as it descends toward Earth?

 

[Yrrah]

Is precession caused by uneven mass distribution in the gyroscope, or by an uneven supporting surface, causing a couple to form (i.e., normal force and gravitation force start to have non-zero cross products)? Is precession analogous to circular motion, the angular momentum vector is having its direction changed by the applied torqued in precession as the linear momentum vector has its direction changed by the centripetal force? As the angular momentum is decreased through friction, the gyroscope can't maintain precession rotation at that radius and translates downward (falls) in a spiral fashion. Is this analogous to the common circular motion experiment with a mass being rotated around a hollow tube by the gravitational force of a stopper, and when you stop rotating, friction reduces the linear speed of the mass, and the mass falls (spirals) into the center because the force is constant, so the radius of rotation must decrease. Is the gyroscope following an orbit as it descends toward Earth?

Some discussion and illustration video:

In the following video it can be seen that the air rifle pellet, which may be seen as a gyroscope initially stabilized be spin rotation and drag, begins spiraling at approximately the apogee of its 71 yards trajectory in flight.

http://smg.photobucket.com/albums/v...71ydrifletotargetslowmotionspiralfrom35yd.mp4

The dynamics at play are: linear and radial velocity decay, the former being at a greater rate than the latter thus resulting in an increase in spin rate per unit distance traveled; decreasing drag coefficient; change from negative gravity acceleration to positive and thus some change in the gravity-to-linear acceleration vector; and some change in lift force.

The pellet's spin is RH clockwise, the spiral is LH anti clockwise. The time intervals can be approximated from known time of flight, linear velocity decay and the near and far zeros as the pellet crosses the reticule.

What is your considered explanation of the dynamics of the onset of spiral flight?

Here is an example of a different pellet flying dynamically stable over the same range/distance, three shots:

http://smg.photobucket.com/albums/v392/Kyogle/?action=view&current=3JSBStratonsat71yd.mp4

Another different pellet, three shots, over a lesser range of 51 yards.

http://smg.photobucket.com/albums/v...Elite3JSBKings51ydspigsilhouetteJan2012-1.mp4

Kind regards.