Here is a brief overview on gyroscopic precession from wikipedia which is the physics phenomenon displayed in the video:
Precession is a change in the orientation of the rotational axis of a rotating body. In an appropriate reference frame it can be defined as a change in the first Euler angle, whereas the third Euler angle defines the rotation itself. In other words, the axis of rotation of a precessing body itself rotates around another axis. A motion in which the second Euler angle changes is called nutation. In physics, there are two types of precession: torque-free and torque-induced.
You can see some of the commenters are very passionate about making cool sciencey things:
“Brilliant engineering. Think I will add a milling machine etc to my workshop. Many thanks.”
We hope you like the video and we look forward to more cool machining videos like this!