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Re: Snub-Antiprism Tensgrities

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Bob Burkhardt

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Feb 24, 2009, 11:19:09 AM2/24/09
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The real expert on prisms is Marcelo Pars at http://www.tensegriteit.nl/
. He probably has some things that might be thought of as based on
antiprisms. I have mentioned the page I have devoted to his work on my
own site: http://bobwb.tripod.com/synergetics/photos/pars.html .
Recently he gave me the coordinates of his masterwork, "de lege stoel,"
and I have made that available in my "Dynamic Tensegrity Views" (see the
last line of my page). Due to the roughness of the values for the
heights for the z-coordinates (just two digits of accuracy), a
mathematical analysis shows these model coordinates to be slightly
divergent from a tensegrity configuration, but everything is within 1%.

Bob

On Mon, 23 Feb 2009 15:51:29 +0100 (CET) Adrian Rossiter writes:
> Hi All
>
> The icosahedron is a snub triangular antiprism
>
>
> http://www.orchidpalms.com/polyhedra/snub-anti-prisms/prisms1.html
>
> The six-strut diamond tensegrity icosahedron
>
> http://bobwb.tripod.com/tenseg/book/chap2_3.xml
>
> can be seen as a tensegrity in a sequence based on the
> snub-antiprisms.
>
> The snub disphenoid
>
> http://en.wikipedia.org/wiki/Snub_disphenoid
>
> is essentially the snub digonal antiprism, and this is the
> first member of the sequence. Here is the corresponding
> tensegrity
>
> http://www.antiprism.com/misc/tens_snub_disph.jpg
>
> The top and bottom polygons are digons, and the strings are
> doubled where they follow the two edges of the digon. The strings
> around the belt of the model form four triangles vertex to vertex
> and alternately touching the top and bottom polygon.
>
> In the icosahedron model the top and bottom polygons are
> triangles, and the strings around the belt of the model
> form six triangles, again vertex to vertex and alternately
> touching the top and bottom polygon.
>
> Apart from the doubled strings the snub disphenoid model
> is the same as the two stage X-module column
>
> http://bobwb.tripod.com/synergetics/photos/x2l2chain2.html
>
> I think I have seen other snub-antiprism tensegrities on
> Bob's site before but I can't see where they are now.
>
> Adrian.
> --
> Adrian Rossiter
> http://antiprism.com/adrian
--
Bob Burkhardt
http://www.freewebtown.com/bobwb/ts/synergetics/photos/

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