Truncated icosahedron time

evansd2 · August 7, 2019, 2:02am

Incoming transmission: ^{We are trunc.} _{Surrender your thumbs} and we will let you live.

Time for a polyhedron, it’s been a minute.

Not much more that I haven’t said about geometric projects before, but a few quick facts and stats:

This is a variant on a truncated icosahedron. It probably has some crazy name but I can’t say for sure what notation is correct for the symmetry.

No glue.
3mm Baltic Birch ply.
180 connectors, 450 arcs. 630 total pieces.

Cuts on about 1.5 full 12x20 sheets, takes about an hour and a half of total cutting.

Assembly is tough on your thumbs, I wore lightweight gloves for a good bit of the process and they still ache. We suffer for our art I suppose

As always, these creatures throw excellent shadows.

Baltic birch ply

UrJac · August 7, 2019, 2:02am

So great!! Thank you for sharing!

dklgood · August 7, 2019, 2:02am

Beautiful project, as usual. Ice your thumbs a bit and then back to work.

pubultrastar · August 7, 2019, 2:26am

Epic! Just fantastic.

davidgal2 · August 7, 2019, 2:47am

That is beautiful. How big is it? I am thinking that it is pretty big since it uses 1.5 sheets of material plus the individual pieces look small.

evansd2 · August 7, 2019, 2:59am

12” diameter.

drelleum · August 7, 2019, 5:10am

How long did that take to assemble??? that’s a lot of pieces.

cynd11 · August 7, 2019, 9:44am

Wow, stellar! The dramatic lighting made it look like it had a red faceted material for the faces and I thought, I know you are a master of material but this is just ridiculous.

arh2 · August 7, 2019, 9:57am

Wow! It almost looks like acrylic the way the light hits it.

evansd2 · August 7, 2019, 11:25am

It took a minute. I didn’t time myself but I’d guess about 3-4 hours. Part of it was figuring out the best way to assemble it, there are more and less efficient ways to do it, which I figured out as I went. If I did another I’d probably shave an hour off at least knowing what I do now.

Yeah that’s cheating Here’s natural light:

(Terrible pic, I’ll probably take a better one later and replace it)

In theory you could achieve that look by painting your Baltic before you start…

pubultrastar · August 7, 2019, 1:35pm

I’m pretty sure that this is a Snub rectified truncated icosahedron. You definitely win the polyhedral championship. I think this might be my favorite piece I’ve ever seen made with a .

evansd2 · August 7, 2019, 1:42pm

Yes but not quite, as the hexagonal and pentagonal faces are rotated on mine as well. That’s why I can’t quite figure out the nomenclature.

I’ll take that as a huge compliment coming from you, I think your work with finished polyhedra has been outstanding.

pubultrastar · August 7, 2019, 1:53pm

Thanks, but I feel like I’m cheating using 3D printed parts. Yours are all laser, and the results are pretty awesome. I have another new polyhedral in the works, and feel like I get more enjoyment out of figuring out the design than the actual finished piece. Each one seems to get more complex, and I like that challenge. What’s next for you?

evansd2 · August 7, 2019, 2:13pm

It’s funny because what I am trying to figure out how to avoid the bigger/better thing, because you can stellate any of these and add parts but that doesn’t really push my buttons anymore. I designed a 1400 piece model about a year ago, and did a test build of one of the repeating corners, but in the end I just didn’t want to build it.

I built this one because I just wanted to shake off the rust of designing and building these guys.

As for what’s next, I have 2 models that I am eyeing. Converting them from 3d models in sketchup to workable lasered models is fun but time-consuming, so I am debating. Leaning toward a pentagonally tiled floret-based model, we’ll see. Doing the math on parts as we speak actually.

Hmm looks like 120 faces and 1020 connectors. Sounds like a lot, we’ll see if I do it.

designvh619 · August 7, 2019, 4:29pm

That is fantastic! Now my brain is turning! LOL

Pearl · August 8, 2019, 1:32pm

These are definitely my favorite projects. I am planning on a 3D printer this year with almost the sole purpose to print the interiors so I can finally tackle one.

Thanks for sharing!

evansd2 · August 8, 2019, 1:41pm

No 3d printers involved here

edyvetter · August 8, 2019, 2:11pm

ah-mazing! wow. thank you for sharing.

drelleum · August 8, 2019, 2:25pm

That’s one of the most amazing parts of this to me. The corners have to have been… exciting to put together

evansd2 · August 8, 2019, 2:29pm

They can be tricky, but 2 things help here: scale, and material. Wood is flexible and has some play, so you can wiggle things into place. If you go too small, you have much less play and it gets more difficult, especially at the end when the rest of the model is reinforcing the position of the parts. For a very small taste of this process and method, check out my octahedron post, they use essentially the same construction method, just on a much smaller scale:

That one goes together in just a few minutes, piece of cake.