1. Spindle

The basis of this example is a helical twisted spindle - an interesting object because of his optical irritating qualities: Showed in rotation it gives the impression of a screw movement up or down.
I show a superposition of two spindles, rotating in opposite directions. This leads to an object with selfpermeation, principially not to realize.

\(\(\(spindle\  = 
Table[
          Show[
{ParametricPlot3D[
{1.8  
                    v*Sin[u/6]*Cos[u + d], 
	\ \ \ \(-\ 1.8\) v*Sin[u/6]*
                    Sin[u + 
                        d], 
u}, 
\ \ \ \ \ \ \ \ \ \ \ {u, 0, 6  Pi}, {v, 0, 
                  Pi}, 
PlotPoints\  -> {128, 
                    6}, 
DisplayFunction\  -> \ 
                  Identity], 
\ \ \ \ \ \ \ ParametricPlot3D[
{1.8  v*Sin[u/6]*Cos[u + d], 
	\ \ \ \ \ \ 1.8  v*
                    Sin[u/6]*
                    Sin[u + 
                        d], 
u}, 
\ \ \ \ \ \ \ \ \ \ \ {u, 0, 6  Pi}, {v, 0, 
                  Pi}, 
PlotPoints\  -> {36, 
                    6}, 
DisplayFunction\  -> \ 
                  Identity]}, 
SphericalRegion\  -> \ 
              True, 
BoxRatios\  -> \ {4  Pi, 4  Pi, 
                6  Pi}\ , 
ViewPoint -> {1.540, \ \(-2.844\), \ 0.995}, 
PlotRange\  -> \ {{\(-2\) Pi, 
                  2  Pi\ }, {\ \(-2\) Pi, 2  Pi\ }, {0, 
                  6  Pi\ }}, 
LightSources -> 
{{{1, 0, 1}, 
                  RGBColor[ .1,  .3,  .9]}, 
{{1, 1, 1}, 
                  RGBColor[ .2,  .3,  .0]}, 
{{0, 1, 1}, 
                  RGBColor[
                    1,  .6,  .2]}}, 
Background\  -> \ 
              GrayLevel[ .9], 
Axes\  -> 
              False, 
Boxed\  -> \ 
              False, 
DisplayFunction\  -> \ $DisplayFunction
], 
{d, 0, 
            2  Pi -  .25  Pi,  .25  
              Pi}];\)\(
\)\)\)