Icosidodecahedral Gift Box Assembly

Yay, polyhedral assemblies! And a gift box, specifically, though a somewhat obnoxious one, depending on whether the recipient enjoys assembling and disassembling things. It's reasonably large (see mug for scale in the photo!)

As you've probably gathered from the title, it's a gift box in the form of an icosidodecahedron, which is the shape you'd get if you took a dodecahedron and chopped all the points off*. Interestingly, when checking to see that I was correct in saying that, I discovered it's also the same shape you get if you chop the points off a good old d20-style icosahedron! Either you're chopping points to reveal pentagons or triangles, and leaving either triangular or pentagonal sides in their wake. But I digress, back to the model!

So, imagine you're the recipient of this gift, and you've finished thanking the giver profusely for their kindness and complimenting their stylishness and appreciation of polyhedral forms. Your thoughts probably turn to how to actually open the thing, and yes, it's time to unscrew bolts! That's the potentially obnoxious part. But it's not as bad as it could be, because there's a driver tool provided, and it's holding the bow in place!

The driver went through several different versions. Not because it was functionally problematic, but because I wanted it to look natural in the bow, but also be fairly obviously a tool when looking closely. The handle part has a very screwdriver-y style to it for that very reason.

Unscrew the tool and the bow will come away, at which point you can start to undo bolts, disassemble the box, and possibly even look at what's been put inside it!

One thing that makes this different to the polyhedral assemblies I made many years ago is that there are no separate interior brackets to hold faces together. One of my design goals with this one was to avoid needing anything more than one model per face and one bolt per edge. I did try to make it work with one bolt per vertex instead, which would have cut the number of bolts from 60 down to 20, but the approach I came up with was far too vulnerable to print issues and easily broken. So, one bolt per edge it is.

Specifically, you'll need:

• 60 bolts

• 20 triangular faces

• 11 pentagonal faces

• 1 pentagonal face with threaded hole for driver tool and bow

• 1 bow

• 1 driver tool

You can of course leave the bow out, and just print 12 normal pentagonal faces instead :)

Print Description

This is an assembly of regular-mode printed parts, and while there's nothing at all tricky in there you'll still want to make sure that things like bolt threads are neat and clean for easy assembly.

Print Dimensions

The pentagonal face occupies 121mm x 116mm on the print bed and is 24mm tall.

Supports Needed?

Not at all!  Designed for straightforward printing!

Scalability

This one should scale up or down fairly easily before things like threads start to get problematic, at which point you might just want to scale the bolts slightly larger or smaller accordingly.

Print Orientation

Pentagonal faces print face-down, triangular faces print face up, and the bow prints right-way-up.

File Location

You'll find this one at at 493 Icosidodecahedral Gift Box Assembly

Link to dropbox post: https://www.patreon.com/posts/31697592

Further Thoughts

I'd forgotten how much I enjoy making these kinds of polyhedral assemblies! Hopefully your gift recipients also really enjoy taking apart and reassembling large numbers of bolts :D

* Note from back at the start - the icosidodecahedron is only formed when truncating the vertices all the way back to the midpoints of the edges that lead to them. So, each existing edge will have two slices through it at the midpoint, and will become a vertex for the resulting polyhedron. If you truncated nearer to the vertices instead there'd be a chunk of the existing edge left in the middle, and the face would have more sides and be a different polyhedron altogether! I'm glad we got that cleared up! :D  

Happy printing!

xoxo

Sven.