Assembeling 5 intersecting tetrahedra

devinejay · Post by **devinejay** » April 5th, 2008, 12:28 am

Yeah I was going to use the modules in the link above in my last post, they look a little harder to construct though.

I was looking at my FIT and I don't actually need to build another one. Whereas the FIT has a lot of internal structure the dodecahedron is just a frame, and mostly empty space. So i have now a FIT with 30 modules at maximum size for the paper I have and all I need to do isake £0 of those other modules, which only need to go from one point to another on the outside of the FIT.

It's really hard to describe what I'm trying to say here properly, but basically I might make the frame over the weekend, I'll let you know if it works.

devinejay · Post by **devinejay** » April 6th, 2008, 11:34 am

It looks like the modules prescribed in that link I posted above are much more suited to creating hexagon faces (does anyone know the name of the standard polyhedra with hexagons for faces?)

I'll have a look around to see if I can find a better model, if not I may have to glue it.

Jonnycakes · Post by **Jonnycakes** » April 6th, 2008, 4:51 pm

devinejay wrote:(does anyone know the name of the standard polyhedra with hexagons for faces?)

A flat plane

Sorry, couldn't resist. Hexagons fit together to make a flat surface-it is impossible to make a polyhedron out of only hexagons.

devinejay · Post by **devinejay** » April 6th, 2008, 6:01 pm

Ah feck,

Well I'm after wasting a load of time now. It seems to be tending to a sphere, albeit a very large one. I guess you saved me a load of time in the end. At the moment it looks like if it did work it would be about 50-100cm wide and take far more than 30 modules. Luckily now I won't make it to the very end to find out that it won't fit!!!

Edit;
The modules form triangles at the junctions. They are equilateral and I think if I continue the model may turn into a sphere after all. Dunno really.

You seem to know you're stuff, hexagons and triangles?

Jonnycakes · Post by **Jonnycakes** » April 7th, 2008, 3:37 am

There is a polyhedron made from hexagons and equilateral triangles called a truncated tetrahedron (I am pretty sure that's what it's called). It is made of 4 hexagons and 4 equilateral triangles and is equivalent to taking a tetrahedron (4 sides-equilateral triangles) and chopping off the corners.

There is also a polyhedron with 20 equilateral triangular faces called an icosahedron. 5 triangles join at each intersection.