Geodesic Domes from Structural Insulated Panels

[Joshua D. Johnson]

I'm interested in building a SIP Geodesic dome and am just beginning to learn about the math behind how panels might intersect. It isn't too hard to figure out how skin geometry might intersect but figuring out how panels might intersect adds another dimension that is stumping me a little. Any hints on math?

I assume:

           8-10" Expanded Polystyrene SIP's cut to ? shapes.

           Aluminum or pultruded fiberglass splines at ? angle mitered to a corner on interior and exterior of panel/structure.

           Hot knife to cut spline slots at ? angle ( I could figure this out once panels were made)

           Assume pre-laminated drywall and possible exterior surface of aluminum

           Short Stem wall or potentially full radius dome (golf ball) per Super Insulated dome on this site.

I'm going to try making the exterior shape in Rhino and offset it inward. I'm imagining the trouble will be optimizing panel size and minimizing weird angles. I'd like all of the shapes to be similar (triangles) but don't know enough about the geometry to know if this is possible. We were at the Maker Faire in NY last year and saw a panel cut dome-ish structure, the owner said "It's easy, just cut everything to 140 deg angles and screw it together". Somehow I don't think it'll be that easy. 

If anyone is in N. Idaho I'd like to collaborate.

JOSH

[Hector Alfredo Hernández Hdez.]

I have thinking very much about this topic.

The maths necesary is related to truncated tetrahedron (no regular, of course), obtaining lengths and coordinates.

Maybe can be more easy using CAD programs (a llittle low),

I will recomend dont use angles, instead of use length only.

what are yours proposals, maybe we can make a bussines togather :)

I have good ideas too.

See you.

2013/9/28 Joshua D. Johnson <objectsu...@gmail.com>

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[Joshua D. Johnson]

Hector,
              To clarify it seems easiest to use the simplest shapes, primarily triangles. I broke down one dome today on Rhino and the triangles seemed to be nearly equalateral. My question is still what the angles would be between the inside skin and outside skin.
               Do you happen to have access to SIPS?

Josh

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[TaffGoch]

Josh,

SIPS has occasionally come up, in past discussions. You might find something of use to you:

https://groups.google.com/forum/#!searchin/GeodesicHelp/sips

Secondly, I think you might be referring to the dihedral angle (actually, split in two; half of the dihedral-angle applied to each of adjoining panels.)

General definitions can be found on page 106 of "Domebook 2"

Taff

[Joshua D. Johnson]

Taff,

      Thanks for the info., I'll look into it further. 

      I opened your 3V dome and after scaling to approx 3' triangles offset the outer dome inwards. Rhino choked a bit but I think I have a good product.. I'll try miniature panels on the CNC and see if they marry up well.

JOSH

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[TaffGoch]

Josh,

In SketchUp, that's how I generally accomplish it (scaling-down a copy of outer surface to make inner surface.) No angle calculations needed.

Easy to read/measure the angle from the 3D model, when it's time to turn on the table saw.

-Taff

[Joshua D. Johnson]

O.k., i did it (in Rhino) but noticed the ground plane is uneven in your model, is that right? It looks purposeful.

I'll try doing the math myself now that i have a little courage.

Thanks!

Josh

--

[TaffGoch]

You're not alone. That's a surprise for many folks.

Generally, the ground truncation must be customized, to produce a level foundation footprint. There are several different subdivision methods, with one or two providing level truncations, particularly with even frequencies. The Kruschke subdivision method will produce level truncations for any frequency, but some people don't like the appearance of the differences in produced triangles.

See this model for comparison of Method-1 and Kruschke subdivision methods (frequency, 3v):

http://sketchup.google.com/3dwarehouse/details?mid=11523bfa33e6123d2137e32e8ebf2b1

-Taff

[Hector Alfredo Hernández Hdez.]

Hi everybody.

I remark that skills maths to reproduce  almost model are very very  dificult,

(this is talking about obtain measure lengths or factor chords)

but , once you take one model, maths to make calculations of triangles panes, is so easy.

See that your panes, have 5 faces , two triangles (in and out) (small & big respectively), and 3 trapezoids.

the more complkicated formula to be used is for to obtain distance from point to line....

¿capichi?

2013/9/28 TaffGoch <taff...@gmail.com>

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[Adrian Rossiter]

Hi Joshua

On Sat, 28 Sep 2013, Joshua D. Johnson wrote:
> I'm interested in building a SIP Geodesic dome and am just beginning to
> learn about the math behind how panels might intersect. It isn't too hard
> to figure out how skin geometry might intersect but figuring out how panels
> might intersect adds another dimension that is stumping me a little. Any
> hints on math?

I have written a program that may be of interest. It makes models
in a style that Leonardo da Vinci used to illustrate polyhedra. The
calculations in the program make the face panels all the same
thickness.

http://www.antiprism.com/programs/leonardo.html
http://www.antiprism.com/examples/200_programs/670_leonardo/index.html

In general, the inner surface will not be a polyhedron. The inner
edges of adjacent panels will not generally interect on the plane
through the outer edges and the model center, and if you cut them
through the plane of the intersection (not through the model
centre) you would likely find that the cutting planes meeting
at a vertex do not intersect in a line, and so the panels will
not fit together at the vertices.

Adrian.
--
Adrian Rossiter
adr...@antiprism.com
http://antiprism.com/adrian

[Hector Alfredo Hernández Hdez.]

i know how all can match very well, not all panels will have same thickness,

contradictorily, big triangles need be more tin :(

2013/9/30 Adrian Rossiter <adr...@antiprism.com>

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[Adrian Rossiter]

Hi Jason

On Mon, 30 Sep 2013, Adrian Rossiter wrote:
> in a style that Leonardo da Vinci used to illustrate polyhedra. The
> calculations in the program make the face panels all the same
> thickness.
>
> http://www.antiprism.com/programs/leonardo.html
> http://www.antiprism.com/examples/200_programs/670_leonardo/index.html
>
> In general, the inner surface will not be a polyhedron. The inner
> edges of adjacent panels will not generally interect on the plane
> through the outer edges and the model center, and if you cut them

I should note, to work on general, possibly non-convex, polyhedra
the program uses cut intersection lines at the vertices that may
not pass through the model "centre". Some of the "faces" between
panels will be non-planar in some models (i.e. the cuts would be
non-planar), but these inner faces aren't included when the model
is a whole polyhedron, which is usually the case.

As there may be interest in producing data to construct models
from fixed thickness panels I will add in an option to use
a fixed centre, and also an option to make panels without a hole.
This is easy to add in, so if you are interested in using the
program for your project I could provide a binary with the
changes.

[TaffGoch]

Josh,

When you scale the outer-surface sphere, inward, to produce the inner surface, the triangle surfaces are parallel, but the planes won't be at an equal separation distance (when measuring normals to the surface). The separation normals are depicted, here:

Note that the "thickness" of the panels are slightly different (the numbers in the top left corner of the image.)

If you force the use of equal-thickness panels, which you must do to employ SIPS panels, "joints" between adjoining panels won't align smoothly. At first glance, all looks okay:

...but, if you look closely, you'll see the problem:

If you 3D-model, to develop a single intersection line, between the two inner-surface PLANES (green and cyan,) the joint line is shifted. Changing the adjoining surfaces cut angle (the angled SIPS-panel cut edges,) works okay, for the two example panels, but introduces changes in remaining panels, adjacent to these two panels, as depicted here:

That's why Adrian wrote that you won't get a "polyhedron" on the inside. Outer, yes, but not inner; or, vice-versa. You can have one, but not both. I've attached a SketchUp model that I used to produce these images, so you can examine closely, yourself:

I picked an arbitrary thickness for the panels, but it sufficed to demonstrate/depict the issue.

-Taff

On Mon, Sep 30, 2013 at 8:38 PM, Joshua D. Johnson wrote:
>
> Why wouldn't the inner plane and outer plane of each panel be parallel?

[TaffGoch]

...I forgot the SketchUp model:

[TaffGoch]

The description, being defined & understood, may not be too severe of an issue, which can not be solved with drywall compound & tape.

It's not much of a difference, after all. It just won't be minutely "precise." You may find that it can be "smoothed over" to your satisfaction, during interior finishing.

-Taff

[Joshua D. Johnson]

:-) I was just going to say that, drywallers would make up the difference inside. I would much rather keep them planar to each other than try tapering etc. 

I abandoned Sketchup about a year ago but guys like you make me wonder if I was missing something. You do a good job of using it both technically and artistically. Thanks for providing these details!

Now for a Cut sheet :-(

JOSH

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[Joshua D. Johnson]

By the way I've used several of the softwares linked at Domerama. If you haven't found these they are well worth perusing.

JOSH

[TaffGoch]

On Mon, Sep 30, 2013 at 11:05 PM, Joshua D. Johnson wrote:
>
> :-) I was just going to say that, drywallers would make up the difference inside. I would much

>  rather keep them planar to each other than try tapering etc.

Agreed -- After all, the discrepancy is only about one-half-of-a-percent (of the total panel thickness....)

[Joshua D. Johnson]

Here are a few Screen shots, interesting stuff. I like the domes that are raised a bit because of the added headroom and angle at eye level.

Screen Shot of first try in Cadre Geo

Screen Shot of Dome in Rhino

Screen shot of panel dimensions

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[Gerry Toomey]

Hello Josh,
 
I've attached a screen shot of a dihedral angle calculator that takes into account the fact that a SIP dome, unlike a framed panel dome such as the so-called Pease dome, has all its panels exactly the same thickness. For most dome geometries, any misalignment of the panel edges on the inner part of the dome will be miniscule, as Taff's SketchUp model showed. I tried to show that in Figure 4.

Are you comfortable with Excel? And are the outputs in the spreadsheet what you're looking for? If so, let me know.

- Gerry in Quebec

P.S. You have to know the dome's chord factors to use the calculator.

On Monday, September 30, 2013 9:38:32 PM UTC-4, Joshua D. Johnson wrote:

Adrian,

        I looked at your program, what types of software can I use it with? I have played some with Python but that's it. I did notice in your forum people using meshcam for various things, it would be very helpful if it could export to a meshcam-able file so I could back out my cutting files in Rhino or another CAD program.

        I have to admit the geometry on this is really beating me up certainly with the added task of needing to find edge bevel cutting angles.

        Why wouldn't the inner plane and outer plane of each panel be parallel?

JOSH

[Joshua D. Johnson]

Gerry,

       This looks good!, I do know the chord lengths but would have to cut back the underside of the dome to panels that were equidistant from center. Do you mind sharing it? DO you have examples of completed domes? I'd be interested in seeing how the geometry changed if at all.

JOSH

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[Gerry in Quebec]

Josh & others,

I miscoded two cells in the Excel spreadsheet that I posted yesterday. That's the one showing the slight misalignment of the inside edges of SIP panels. Fortunately, the main outputs of the calculator -- the dihedral angles over panel edges -- are unaffected.

 

I've corrected the errors and will post a new file shortly. I have deleted the earlier Excel files from the conversation.

 

Sorry about that.

- Gerry in Quebec

 

Here's my Oct. 1 message to Josh:

 

Sorry, I don't have any examples of completed SIP domes.

 

Here's the Excel spreadsheet. With this calculator, the vertices (nodes) all have to be equidistant from the spherical centre of the dome, but not from the centre of the floor. Only when the dome is a hemisphere are the spherical radius and floor radius the same.

 

- Gerry

[Gerry Toomey]

Josh & others,

Here's the corrected Excel calculator for dihedral angles.

 

- Gerry in Quebec

[Ashok Mathur]

Dear Joshua,

The link below may interest you as it relates a Japanese companies SIP domes.
There is huge variety on offer

http://www.i-domehouse.com/movie.html

Regards
Ashok

[TaffGoch]

We would be remiss, to not reference SIPsmart ARCX domes:

www.sipsmart.com/dome/arcx.html -- or -- sipsmart.com/arcx-domes/

It's been awhile since they've been mentioned, yet I haven't seen any ARCX dome photos. I have to presume that, either, they need to update their website with photos, or they haven't been selling many.

[Paul Kranz]

Josh:

 

I can help you with the math for the face angles of the triangles, if that is what you are looking for.

 

Paul sends...

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Very high regards,

 

Paul sends...

ReviveTheFlame.com

[Joshua D. Johnson]

I've seen SIPsmart ARCX Domes, not impressed. Bucky intended for domes to represent the future of design and fabrication., their product doesn't really fill the potential of SIPS, Modular construction or Geodesic design.

Josh

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[Doug Dale]

What if one were going to use a timber frame for the dome and just wanted to skin it with SIPS panels?

[Joshua D. Johnson]

Seems like you would still want the exterior sheathing to mate up well and thus the angles would still have to be correct.

Thats an interesting approach though. If you just rough cut the panels and threw every other one up one the frame you could trim them to the frame then fill and trim again. As the frame is structural it wouldn't matter if the panels were quite right.

My two cents.  JOSH

--

[William Fisher]

I am waking up this older thread. SIPS really if you think about it should be the future of geodesic buildings. It would be the ultimate panelized system. All you need is to cut the triangles from the SIPs and rip your struts/splines with the correct bevel. A 3v larger dome would be easy to construct. Blank SIPs panels can be bought in up to 8'x24' sizes. Cost wouldn't be much different using 6 1/2" SIPs. Hardest part would be the weight of lifting them into place, but could easily be handled by splitting the triangles into 2 pieces right down the middle (kind of what Sipsmart does).

Since the splines used in normal Sip construction would replace the struts, they would need a double bevel. Easy solution would be use 2 boards, 1 on each Sip triangle. Cut deeper into the insulation on the ends of the Sip triangles and mount the splkine/strut flush to the outside triangle edge. For the next triangle mount the spline/strut to the triangle already in place then slide the next triangle onto the spline/strut.

Biggest concern using Sips would be waste. 1 foot of scrap plywood is much cheaper than 1 foot of scrap SIPs.

Bill from Pa

[Joshua D. Johnson]

Bill/All, 
          The issue of waste is easily mitigated on the manufacturing side, Splinters could be pre-bent steel.
          I started the thread because I had recently become employed at an EPS foam plant that among other things manufactures SIP's. I built and operate a 4 axis outside cutter that i'm getting better at programming. If I could wrap my head around the math a little better i'd love to cut some small dome panels and take the next step towards making this a reality.
       
Josh

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[William Fisher]

Josh,

SIPs masked any house better. The splines would not be an issue. If you use 6 1/2" SIPs simply ripping down 2x8s with the right bevels works.

I am working out a plan for a 38' 3V 4/9 Kruschke method Dome now. My issue is that online calculators are set for single strut systems not a panelized system. I need the bevels and angles for panels, they would transfer over to SIPs. SIPs because if the weight can be an issue for the actual dome raising. Sipsmart recommends a crane. I feel by splitting each panel into 2 pieces, the weight would be low enough to hand lift them into place.

In your original post you mentioned 8-10" SIPs, why? Moist domes are made from 2x4 or 2x6 frames. Why not use the same SIP size? SIPs are stronger to start and they are much better of an insulation blanket.

Cost wise, not much different. Yes you can stud and sheath a dome very inexpensively but once you add insulating it, the cost equals out.

Bill from pa

[Blair Wolfram]

 "SIPs are stronger to start and they are much better of an insulation blanket."

The spline of a typical SIP is a 4"x4". A hub dome, or a skeletal system uses a single 2" frame member, reduces the lowest

 r-value exposure of the wood frame by half, making a strut dome more efficient.

Attached are a couple pics of a SIP dome I built over a steel frame. These SIPs have no spline, making an un-interrupted, monolithic insulation barrier. Like turning a styrofoam cup up-side-down.

Blair

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Blair F. Wolfram
Founder, Dome Inc.

thedo...@domeincorporated.com

http://www.hurricanedomes.com

888-DOME-INC or 612-333-3663

[William Fisher]

Blair,

Thanks for joining in on this thread. Nice to have an expert join in. Maybe I am over thinking the this but in the designs I have looked at, most have struts and additional 2x lumber in the dome panels. Wouldn't this work the same as walls in a box house lowering the r value? The beauty of the SIPs is that the only break is at the spline. Something needs to be placed between the sips to connect them, as I see it most use 2x lumber which is only covered by the OSB.

My panel idea was using 2x6 frames and 2x4s inside as studs but stager them one up against the interior the next against the exterior. Then use spray foam insulation which would fill in between the 2x4s. Thus creating the best insulation blanket. Then use a layer of rigid insulation panels on the outside covered by densdeck to apply my roofing material to. Just fgill the gaps between the rigid panels with spray foam. Just thought SIPS would replace everything (except the roofing of course).

I need a well insulated home, the wife is from Panama and hates being cold.

Bill from Pa

[Joshua D. Johnson]

Our system uses splines rather than a full let in 2x or 4x so there is continuous insulation throughout instead of breaks on panel edges. My thought was to let in a bent piece of heavy gauge steel inside and out as it could be bent easily. Self tappers and urethane would complete the connection.

At R-4.5/in x 10-12" you'd get a decent near superinsulated value (ie transmisivity=0)

An earlier post linked to a calculator that adjusts angles so everything is flush.

Josh

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[William Fisher]

You still need something to add structure at the seams between each sip panel.

[Joshua D. Johnson]

In a regular house the splines would be screwed and glued. Not sure with a dome., why would it be different? I'm sure 2x's aren't required.

Anyone up for helping me with panel design? I could trade for something. I'm in N. Idaho., design could be virtual though.

Josh

On Oct 8, 2014 3:58 PM, "William Fisher" <fisher...@gmail.com> wrote:

You still need something to add structure at the seams between each sip panel.

[Dan van Wylich]

Everybody seems to talk about using frames, but since we are talking about SIPs wouldn't it be possible to use structural glue?
 SIPs also come in Magnesium Oxide boards (water proof) which could do away wit external cladding. True igloo style :)

[Joshua D. Johnson]

I've never seen SIPs done that way, sounds good though. One of these days i'll sit down and make up some section drawings. Seems like others are doing it but it'd be nice to distribute them freely. I don't understand the geometry that we'll..

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[William Fisher]

I am working out details for plan to use SIPs on a 3V Octahedral Dome that will cut in half with a 2 story rectangular structure sandwiched in the middle.

So far it looks very doable. After pricing spray foam solutions, it appears to be actually less expensive than framing and spraying.

[Hector Alfredo Hernández Hdez.]

try mex method,
the triangles are more similar between them...

do you want factor chords for 3v?

2014-10-31 7:02 GMT-07:00 William Fisher <fisher...@gmail.com>:

I am working out details for plan to use SIPs on a 3V Octahedral Dome that will cut in half with a 2 story rectangular structure sandwiched in the middle.

So far it looks very doable. After pricing spray foam solutions, it appears to be actually less expensive than framing and spraying.

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[Hector Alfredo Hernández Hdez.]

here is an example

http://www.domerama.com/calculators/octahedral-5v-mexican-method/

[Hector Alfredo Hernández Hdez.]

Check that layout A,B,C,...

is not standar way....

"same level, same strut"

example for 5v "horizontal" struts
 

      A

    BB

  CCC

 DDDD

EEEEE

[Gerry in Quebec]

Yes, try the Mexican Method layout. It has one more triangle type than method 1, but I think it's a better looking dome because of the triangle similarity Hector mentioned. See the attached jpgs for comparison.

- Gerry

[William Fisher]

I like the 3V Mexican model, I actually want the pronounced/obvious triangle look. Only 2 triangles makes even a novice like myself feel confident I can do this.

My latest plan has a 25'D dome extended with 4' sections and a 32'x12' two story middle section. Basically the Sipsmart 29-9 just done the way I want it.

[Gravity]

Hey Guys,

I just Googled "sips panel geodesic dome" and landed here.  I've been tinkering with domes for years now, but just learned about sips panels.  Coincidentally, right around the time that this thread was getting started I was working on my own dome design that I also have a patent for.  Check it out:  https://patents.google.com/patent/US9506240B1/en

I set out looking for a way to put a dome on a square base, and that's what I came up with.  It simplifies things by reducing the number of different angles in the mix, has square elements, and is made with just two different strut lengths.  

Also, I did the vector algebra the old-fashioned way with a pen, paper, and calculator (Excel).  I used Excel to spit out the vectors and plotted them with gnuplot.  

Cheers!

[lemondealc .]

Nice work. Thanks for sharing.  Have you posted any videos of these structures online (YouTube, etc)?

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[Gravity]

Here's a picture from some early tinkering and experimentation.  I've been trying to work out solutions for all the other problems before I start trying to build a really big and permanent one.

[lemondealc .]

Interesting. What "other problems" are you trying to solve? Take a look at some of the videos I've posted on Youtube of my geodesic dome hubs. I'd like to think you could use my hubs to build your new geodesic design, but I'd like to hear your thoughts. 

https://www.youtube.com/watch?v=2TAMG-Ntfjw  

On Thu, Jan 23, 2020 at 11:42 PM Gravity <gravity...@gmail.com> wrote:

Here's a picture from some early tinkering and experimentation.  I've been trying to work out solutions for all the other problems before I start trying to build a really big and permanent one.

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[Gravity]

I've been trying to rethink all of it to get the right combination of approaches for ease of installation, and reduced cost.  Ultimately, I want to land on something that could be produced and sold as a package that is viable not just for people who are nerdy about domes (like me).

I'm thinking that SIPs might be the link I was missing.

Yes, you could use hubs for my design, but hubs are one of the things I've been trying to engineer out of the equation.  As you can see here, these are the 52 identical triangles that make up the dome, and they simply fit together.

[lemondealc]

Hello! I understand your thinking and I am motivated by the same goal: namely to get more people building domes. 

I am going reply to you privately so I could give you my cell number. I'd love to chat a bit if you have the time. My name is Andrew. 

If you don't have the time to chat I would like to point out a couple of things that I've concluded while working on my domes. 

1) If power tools are required to build you dome you are imminently raising the age and skill level that is required to build it. I've watched kids as young as 10 building my domes because it doesn't require any power tools. 

2) Panels require a lot of bracing and a lot of skill. It looks from your pictures that you are building triangular panels first, which is a typical way of building dome that use wooden struts. However, it also requires a lot of clamps to hold those panels in place. I believe I saw one picture where your dome is completely held together with clamps. Obvious the dome covered in clamps was probably because it was a temporary structure. Still, this need for compression forces is a sign that your system lacks the kind of tensional forces that help the frame with stability and flex. 

I simply don't think panel systems are the way to go (at least for the space frame). Again, consider a dome that this 100 feet in diameter: can you imagine the weight of the panels as they sag and the stress that puts on the system. It requires a lot of bracing to keep it all up. 

I'm not totally against panels though. For smaller scale structures that are build by professionals they work just fine. Have you seen the panel system from Geoship.com?

As for my domes, I build them one strut at a time. This may seem cumbersome and time consuming, but it allows me to build the dome as a one man band. In addition, it can be sped up with a parallel workforce, which is going to be required anyway if you are building a large complex panel system.  

3) Tension is a critical consideration for force distribution. The thing that impressed me the most about Zip Tie Domes and what inspired my own design is that Zip Ties can create tension that integrate the entire structure so it can distribute forces. If I hit a long PVC strut on my big domes, I can see the forces spreading through out the structure. 

That being said, I REALLY LIKE your design and I hope to build one. Cheers. 

[Gravity]

Certainly, you cannot simply be satisfied with the compression strength.  No building inspector will sign off on the structure if it can pull apart at the joints in an earthquake.  The nice thing about the wood fitting together neatly like that is that you call pull it together with simple screws.  When the triangular plywood sheet is fashioned to the outside, there is no pulling it apart.

Anyways, I have no consideration for having children build my domes.  Also, the idea is not for other people to manufacture those panels.  The idea is to sell the panels, which fit together easily, and can even be built from the bottom up.

The clamps were just for testing.  However, the clamps are nice because nothing is permanent and you can make adjustments etc... up until you put the screw in and remove the clamp.

The picture shows frames that were made from 2"x2" material that was ripped from standard 2x4's.  The resulting structure, was 12 feet in diameter.  It was strong enough for me to climb all over.  However, when full 2x4's are used on each panel, then joined to make 4x4's on each strut, it's practically indestructible.  I did that on the first one I made, and found that that was heavier and stronger than is necessary, for something small.

The size I'm going for, ultimately, is that of a cabin or small house.  This is the basic idea shown, where the short strut length is roughly eight feet:  

[Gravity]

I should qualify that by saying that in the context oh my patent, of course, I have consideration for any and all uses.  BTW, I call it a "Palindome" because it is even on the x and y axes.

[Dx G]

I see this discussion from some time ago.

Note that one good way to connect panels for a dome has been patented and described well.  It appears to me to be a very solid system that lends itself to fairly easy use.  Just wanted people to be aware of this in case they had not seen it before. It can be used with or without the routine spline joining system typically used with SIPS, but the latter are usually for flat rather than dihedral joinery.

US6173547

DxG

[Ashok Mathur]

In general rhombic tricontrahedron based structures have been neglected by dome builders.

Its advantages over icoshedral structures are many but it has an optical illusion issue that had discouraged me.

Even though the end structure may be smooth and even , it looks as if one panel is inset.

Regards

Ashok

Sent from my iPhone

On 13-Dec-2022, at 10:34 PM, Dx G <yipp...@gmail.com> wrote:



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