Johnson Polyhedra

It feels as though the MakerHome blog by Laura Taalman (aka @mathgrrl )  is going to be a source of great fun for a long time.  The entry on March 6th provides several links to sites for printing 3D polyhedra and shows several examples of her prints:

http://makerhome.blogspot.com/2014_03_06_archive.html

The link to Johnson polyhedra grabbed our attention and we decided to print the mysterious object known as  J79 – the “Bigyrate dimished rhombicosidodecahedron” (it has two colors because our white spool ran out during the print):

I had not previously heard of the Johnson polyhedra.  For me finding out about objects like these is part of the great fun that the 3D printer brings – you can now hold these objects in your hand rather than just reading about them, so there’s more incentive talk about them with kids (and to just play around with them!).

And play we did.

After printing we decided to see if we could make the same shape with our Zometool set.  Here we actually ran into a little bit of difficulty when it appeared that we could only make about half of the shape.    Just before were going to call it a night, though, we noticed that the combination of a short and medium red piece was the missing link we were looking for.  Here’s the finished product:

These two videos give a better view of the objects:

Finally, if you would like more information on the other Johnson Polyhedra, both Wolfram Mathworld and Wikipedia sites have quite a bit of information:

http://en.wikipedia.org/wiki/Johnson_solid

http://mathworld.wolfram.com/JohnsonSolid.html