This is now much more model dependent to avoid clashes with the rotor objects and other
representations:
- For the torsionless isotropic cone, a single z-axis is created.
- For the double rotor, a single z-axis is produced connecting the two pivots, from pivot2 to pivot1.
- For the pseudo-ellipse and free rotor pseudo-ellipse, the x and y-axes are created.
- For the torsionless pseudo-ellipse, all three x, y and z-axes are created.
- For all other models, no axis system is produced as this has been made redundant by the rotor
objects.
