Truncated tetrahedron yurt?

[sparr]

I'm sitting here playing with geometry ideas and this came to mind:



The floor is the same size as the "H5" "6ft" hexayurt. The green walls are three half-size hexayurt roofs leaning together, with four actual equilateral triangle panels. This design takes 5.5 sheets of material, and would pack into a 48"x48"x11*t bundle. The extra half sheet of material buys a bit more elbow and head room.

The major con here is door placement. I've read much lamenting about how small a 30"x36" door in one side of a normal 6ft yurt feels. With this design, my door would be a bit smaller than that, even.

Has anyone built something like this before?

[Elderberry]

First, that isn't a Yurt. (I assume you're just calling it a yurt because it is made from the insulation panels?)
Second, why?
Unless I'm missing something, saying it would present a challenge setting it up on the playa is being generous.

Have you ever built a standard yurt?

[Sham]

A standard yurt is shaped in such a way that the wind actually forces it to stay in place. While some do collapse, that design is meant to keep that from happening.
The design above may actually go rolling around the playa during a bad wind storm.

[burner von braun]

go rolling around the playa during a bad wind storm.

psst.. don't go there Sham

[Ratty]

Typing....deleting.....typing....deleting. Biting my tongue. Resisting...Whew. Made it.

[caffeineslinger]

I think your design looks cool and it gives more headroom with less material, but I feel in a high wind it will be pick up and tossed like a huge ball.

I'd still like to see it built though, just in a different setting.

[sparr]

First, that isn't a Yurt. (I assume you're just calling it a yurt because it is made from the insulation panels?)

Yeah, my bad. I started looking at hexayurts and pentayurts, then the "nearodesic" dome plans that seem to have spun off the hexayurt project, and all of that stuff was sorted under "yurt" on various wikis. Yurt was definitely the wrong name for this idea on its own, though.

Second, why?

Lots of "why"s... I'm looking at the 6ft hexyurt in the first place so that it transports in a 4x4ft footprint instead of a 4x8ft footprint. I don't have wind loading simulation software, but generally a more spherical structure has a lower Cd and is less prone to getting knocked around by the wind. Based on other projects using dome shapes (geodesic and otherwise) I expect it to be stronger under compression than the hexayurt's approximation of a V1 dome.

Unless I'm missing something, saying it would present a challenge setting it up on the playa is being generous.

It should be easier to set up than the quad-dome and tri-dome designs, right?

Have you ever built a standard yurt?

I've erected a yurt, and a few other flat-sheet structures, but not on the playa.

[tamarakay]

The yurt people in my camp pre-tape most Of their panels together for easier playa put together. Can any of this be pretaped. Then accordion it flat?

I like seeing new things.

[sparr]

The yurt people in my camp pre-tape most Of their panels together for easier playa put together. Can any of this be pretaped. Then accordion it flat?

Yes. There are 22 triangular panels total. 18 of them are three normal hexayurt-style roofs, which will accordion down in the normal fashion. The stack of parts will have two whole roofs as single pieces, then two half-roofs, then the four separate triangles, so 8 pieces total. I could get that down to 4 pieces with some really creative accordion-ing, but that would probably be confusing during deployment and storage.

[burner von braun]

I like seeing new and unusual concepts out there too. I think we all do so long as they stand a good chance of surviving and not mooping. What technique are you thinking about using for tying it down?

[sparr]

I like seeing new and unusual concepts out there too. I think we all do so long as they stand a good chance of surviving and not mooping. What technique are you thinking about using for tying it down?

First draft plan is to basically make the dual polyhedron from rope, and guy from that. So, a "halo" around the top, and then another one around the bottom, connected to each other with /\/\/ ropes like on the sides of a drum, and a Y of rope across the top. Since the structure is convex, I can tighten all of that snugly without guy lines, so the ropes hug the structure. Then I can guy from the upper halo. I'd plan to have all of the ropes pre cut and tied except for the /\/\ lines.

[Meat Hunter]

sparr,

I too like to see all the interesting ideas and creative innovations that the playa brings out in folks.

I say, go for it.

Regarding anchoring it and its round-ish shape, one way that you could go would be with a heavy duty cargo net over the top. You would have a good many choices for anchoring points around the edges of the net and you would get good coverage.

There have been long discussions here on e-playa regarding the use of lag bolts as the ground anchor points. I used lag bolts last year to anchor my 18' playa dome and it worked out really well.

Keep plotting and planning and I am sure that you will come up with something that is workable.

[trilobyte]

Interesting shape, but not at all a yurt. Typically yurts are portable round-sided tents. The hexayurt is a variation on a yurt, in that they do six-sided walls and use cheap/efficient construction materials....and were designed pretty much as cheap and affordable shelter for poverty and disaster stricken areas.

What you're depicting seems to be more in line with a geo-dome. I don't know of anyone who's used the relatively flimsy yurt panel and taping scheme on a dome, but if you know your shapes and shade structures and think it'll work then by all means knock yourself out. Do take pictures, and post-event you can share your experiences. Good luck!

[digital]

Interesting design. As a first timer, I'd personally go with a known working model. However, if you decide to use this shape take pictures and document the process. Can't know until you try it! Good luck.

[burner von braun]

I know that maladroit often speaks of the virtue of the thicker 1.5" or 2" foam boards around here, and he knows his stuff. This design might benefit greatly from the stronger material. You would still have your 4' x 4' transport package, just thicker.

[digital]

^ +1 on the 2" material

[mooserider]

Shouldn't that technically be called an icosahedron (or at least a ground-clipped one)?

[sparr]

Shouldn't that technically be called an icosahedron (or at least a ground-clipped one)?

Naming of shapes gets a little fuzzy when you start triangulating everything. If you consider each set of green triangles to be a hexagon then this shape is 4 regular hexagons and 4 regular triangles, which is a truncated tetrahedron, in the same way that the quad dome is half of a truncated octahedron. Once you split the hexagon into six triangles and bulge them out for stability, then you get a shape made of two different types of triangles. That family of shapes mostly doesn't have names, nor is there a useful generic name for a 28-gon.

This concern comes up in modular origami a lot. If you want a pentagon but you only have equilateral triangles, you use five of them (like the roof of a pentayurt), but now does your model have one pentagonal shape or five triangular shapes? It gets worse when you go another level down, such as a unit that only makes 45-45-90 triangles, and three of those make a short triangular pyramid with an equilateral base, then five of THOSE make a bumpy pentagonal pyramid, and you might have 15 right triangles or 5 equilateral triangles or 1 pentagon depending on how closely you look and count.

[Eric]

Shouldn't that technically be called an icosahedron (or at least a ground-clipped one)?

Naming of shapes gets a little fuzzy when you start triangulating everything. If you consider each set of green triangles to be a hexagon then this shape is 4 regular hexagons and 4 regular triangles, which is a truncated tetrahedron, in the same way that the quad dome is half of a truncated octahedron.

Too many words - call it a "foam dome" and be done with it.

As long as it has room for you & your stuff while you're sleeping, I say go for it. I'd do the 2" boards like suggested above, and I agree that the cargo net would probably help hold it down better than just a halo of ropes. I've seen un-staked metal domes roll in the wind, so this is definitely something you would want secured. Do take lots of photos.

[jimthompsonmd]

First, that isn't a Yurt.

Well, but neither are those hexagonal, taped structures made of rigid polyisocyanurate insulation.

Generally, a "yurt" is a more or less round dwelling, with a more or less conical roof, typically made with a structural skeleton supporting external coverings which keep out the elements.

[Elderberry]

First, that isn't a Yurt.

Well, but neither are those hexagonal, taped structures made of rigid polyisocyanurate insulation.

Generally, a "yurt" is a more or less round dwelling, with a more or less conical roof, typically made with a structural skeleton supporting external coverings which keep out the elements.

Actually, the most defining characteristic of a yurt is the tension band. And, the "original" design of the hexayurt fits your description pretty well. (Which was probably why the inventor called it a "Hexa"yurt"" in the first place. )