This thing's goal is to illustrate the conic sections by changing filaments colour to create horizontal sections of cones that differ by the angle their axis form with the plane.

The central cone's axis is vertical and its sections are circle.

The axis of the twin cones is horizontal and there section are hyperbola (this curves have 2 parts and 2 cones are needed to show them).

The parabola is illustrated by the one that lie down: the angle between the axis and the base is the same as the one between the axis and the cone's surface.

The last one with an angle intermediate between the central one and the one of the parabola illustrate the ellipse.