Usually the first axis of inertia is drawn horizontally, and at the end of each axis the eigenvalue and the percentage of total inertia explained by this axis is written.

Each of these is called an “axis of movement” (or “axis of inertia” or other term).

The position thereof is stabilised by the rotation about a main axis of inertia and by the damping effect of the surrounding medium and the driving magnetic field.

The rotational body (21) is rigidly connected to an energy store (35) and the axis (46) of the motor shaft substantially coincides with a main axis of inertia of the rotational body.