7 Replies Latest reply on Aug 21, 2015 12:43 AM by Josh Sinclair

# Dodecahedron Pyramids

Hi all,

I am relatively new to Solidworks, and am trying to make a dodecahedron assembly, out of 12 pentagon based pyramids. I am having trouble getting these pyramids perfectly dimensioned.

I am lofting the pentagon to a point a specified height above the pentagon. I have followed this site to get the distance between pentagon and point. Mathematical Misfits - three-dimensional solution | plus.maths.org

I entered my answer to 15 decimal places yet I am still getting something wrong. The side length of my pentagons is 22mm, is there a better way to go about this?

• ###### Re: Dodecahedron Pyramids

Make it with sketch blocks.

Start with a 2D sketch. Sketch a single pentagon, then turn it into a block.

Then start a 3D sketch. Insert pentagon blocks and constrain them to the base 2D sketch. Repeat 10x (the last face makes itself).

• ###### Re: Dodecahedron Pyramids

Addendum: it seems that 3D sketches don't play nice with too many blocks. You likely will need multiple 3D sketches.

• ###### Re: Dodecahedron Pyramids

thanks for the suggestion, however It is essential that the dodecahedron is constructed from pyramids, as there are extruded 'tracks' running through each face.

SO my question should be how to correctly make this pyramid. Thanks

• ###### Re: Dodecahedron Pyramids

Maybe... just maybe... someone could use the sketches to make solids. You have to be willing to actually do this, though. Wishing isn't enough.

• ###### Re: Dodecahedron Pyramids

Here is a method of creating it in context of an assembly. I started by creating the part and sketching a hexagon. Then I added two more instances of that part and mated the hexagon sketches to each other to form part of the dodecahedron. Then I created a 3D sketch in the assembly joining centerlines protruding from two of the pentagons to find the center where they meet. Then I edited the first part in context of the assembly, started a 3D sketch, and placed a point at the center location. Then I lofted between the pentagon and the point. I've attached the assembly, and you can open the virtual part to see the single pyramid.

• ###### Re: Dodecahedron Pyramids

Exactly what I'm after, thanks. Although I just figured out the corect equation, I was doing something wrong originally changing my answer by .3.

Is it possible to offset an axis a distance defined by an equation? If not, I'll go this Route! Thanks again