The model is made from two overlapping parametric curves. There's not really any point to it; it's just a curious model that I was interested to see for real. Aesthetically it makes for an interesting object. The curves are both rendered using the following formulae:

(x, y, z) = (40*cos(atan(2*sin(a*10*p)))*cos(2*a*p), 40*cos(atan(2*sin(a*10*p)))*sin(2*a*p), 40*sin(atan(2*sin(a*10*p)))),

radius = 3*((3+sin(4*(p+((1+sin(10*a*p))*8*p))))/4),

(r, g, b) = (1, ((1+sin(4*(p+((1+sin(10*a*p))*8*p))))/2)*0.6, ((1+sin(4*(p+((1+sin(10*a*p))*8*p))))/2)*0.4).

This was actually a function co-created with Dr Martin Randles. The threads have been thickened since the first version and the print now comes out very nicely in Full Colour Sandstone and is surprisingly sturdy.