We parametrize the torus
knots by *s* in [0,1]. Let *w* be the rational number such
that the curve winds around the meridian *w* times when it goes
around twice the length of the torus. The speed can be computed as
a function of *s*, *t=s*w*, and the two radii *R>r*
that define the shape of the torus. The speed assumes its minimum
*R-r* whenever *w=0* and sin*t=1*. We transform speed
using *f(x)=(R-r)/x* and produce the models by sweeping a circular
cross-section with radius proportional to *f* of the speed. Growing
*w* increases the speed and produces progressively skinnier tubes
that wind more and more around the meridian.