Last enrichment activity - colorful stellated dodecahedron
byon 01-11-2011 at 07:04 PM (49332 Views)
Today was my last enrichment activity with the kids from my daughter's school (6th graders). For our last project we put together a stellated dodecahedron with the property that for any face you look at, the star is the same color (I'm not explaining that well - look at the pictures to see what I mean). Each of the kids got their own "kit", and three of the six had the figure complete or almost complete in just one class period (43 minutes), with the rest about half way done.
The models are made up of twelve different "spikes", each of which is its own piece of paper.
One of the problems with making paper models of stellated polyhedra is it is a lot harder to make the concave joints with flexible paper, especially as you get to the last few parts of the model. You just can't get your fingers in the right place to put tabs in place or to hold things together to properly glue them. And it gets really hard to fit tweezers in to help, since everything is already closed up.
So I made models with holes in the faces. This turns out to make it a lot easier to put them together, as you can get tweezers in the right place without any difficulty. And I think they look pretty cool too :-)
For this model I decided to use tab-and-slot design for the individual spikes, but to use something else to connect them all together. I actually took 1/2" mailing labels, and cut them to length (a sheet at a time). This made nice, white stickers, which made it easy to make a complete kit. The stickers are used to connect the five sides of the base of each of the "spikes" to its neighbors.
Each of the panels in the kit has a different arrangement of colors. You need a little instruction sheet to figure out what connects to what. While it is a bit confusing, I made one of those as well.
The source files are here. There is a uncolored version that has Inkscape files, and PDFs ready to be laser cut. The color ones depend on printing and then cutting with registration marks, so all of those files are in Silhouette Studio format. No Inkscape for the color ones, though you can probably open the PDFs in Inkscape and get something approximating a native SVG file.
No-color one, can be laser cut (PDF, svg)
Each of the three color sheets with spikes:
sheet1 (PDF, studio)
sheet2 (PDF, studio)
sheet3 (PDF, studio)
Instructions (two sets per page - I just cut them in half):
instructions (txt, docx, PDF)