This is another version of some sculptures I made before, to see them watch earlier posts. This time another kind of movement. Explanation below.
A minimal of three small circular movements contribute to driving the two lobed nephroid form.
In a normal wave (for instance a surface water wave) small circular movements of the water molecules with their centre on a straight line make a wave, each circle movement of a water molecule is shifted a bit further in a angular displacement to the small centres of the circling movements. The nephroid is kind of wave around a base circle made by another circle half the size of the base circle, roling around this circle creating the curve of the nephroid. To make a solid nephroid move we have to make circlular movements again. This time the smaller circular movements have to be all in fase, because the straight line of a wave principle is now bend to make a full circle. So some inverting have been taking place: The dynamic curve of a nephroid became a solid, and the straight line of a normal wave principle has become a full circle. We must compensate this by a straight line principle, which is the parallel frame which makes the three circular movements of the pins constant and identical. From onlooking position the three pins are moving in fase by a parallel moving frame. Seen from out the centre of the nephroid the circle movements are displaced 120 degrees, each movement contributing to pulse the nephroid around a fulle circle.
The centre of the three pins moves around the centre of the nehproid (the eccentric).