When a gyroscope precesses, what is pushing it along?

[24forChromium]

This is the kind of gyroscope that I am talking about:

Where did the kinetic energy of precession come from? The gyroscope's spinning angular inertia? If so, how does it transfer into the precession? Is a torque applied horizontally (along the x-y plane) when the system is under the effect of gravity? If so, why? If such torque is present, is it constant or does it reduces as the precession speed increases?

 

[Dr. Courtney]

https://en.wikipedia.org/wiki/Precession

 

[24forChromium]

https://en.wikipedia.org/wiki/Precession

you know this doesn't work.

 

[Drakkith]

you know this doesn't work.

What doesn't work? The link? It works fine for me.

 

[rcgldr]

Where did the kinetic energy of precession come from?

Someone or something has to initally impart the rotation needed to match the speed of precession for the gyroscope to remain exactly horizontal. If the gyroscope is just released, there is a transition where the gyroscope tilts down a bit, converting gravitational potential energy into kinetic energy related to precession. The precession related torque is instant, but the reaction is delayed by a small amount. In an idealized case, the gyroscope would cycle down and up while the rate of precession would increase and decrease, and the total energy would remain constant.