About this website: this site is all about building and modeling geodesic domes, but with a different approach. A geodesic dome normally uses struts or chords, which are straight pieces of material (be it wood, metal, etc...) and are connected by “hubs”. I found a way to make models and structures using curved materials for a true sphere or “infinite curvature” using curved or bent wire or rebar that's tied together at overlapping segments.

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This unique type of dome is built from wire or rebar using spreadsheet calculations from an input radius. They are basically the same calculations used in “hub and strut” construction, only the wire or rebar overlaps where normally the hubs would go... For measuring straight pieces of wire/rebar before they are bent - I take the “chord factor” or measurement and adjust it for a curved arc about the same radius of the dome.

The overlapping wire/rebar causes a need to make 4 overlapping courses of different radius (see diagram):

Course 1: Outermost course or “hoop” wire/rebar - which helps hold the dome together (like metal hoops around a wood barrel).
Courses 2 & 3: These are the middle wire/rebar courses, which are arranged diagonally.
Course 4: Innermost course, in which wire/rebar is arranged vertically in dome.

All 4 courses hold the dome together “geodesically”, as well as the overlaps holding the dome together by both tension and compression. The pattern of wire/rebar overlaps are also repeated throughout the whole dome in “perfect symmetry”. A similar arrangement is done with rebar (but not with Geodesics) at Monolithic Dome Institute, where they use it as a basic frame to spray shotcrete (concrete sprayed from pump) on.

The wire or rebar also has another advantage in construction - there are a lot less “courses” needed than compared to the same frequency hub and strut model (frequency is the number of subdividisions from the main “geodesic” icosahedron, the basic mathematical shape for these models). The wire/rebar runs in continuous arcs or lunes around the whole dome - and not need to be “chopped up” to make individual struts.

The way to contruct these models/structures is not that complicated once you have a spreadsheet that simply takes the dome radius input and tells you where to cut and mark the wire/rebar. I have a series of spreadsheet plans to make domes of just about any diameter, also any frequency from 2v (v denotes the number of subdivisions) to 16v.

The wire or rebar is first marked when layed straight (or marked around a circular form) from the spreadsheet (see Instructions for assembly and materials). Smaller models from 1-3 feet in diameter are a bit more tedious to tie once marked, so they are tied over a cardboard form of 2 frequency. Larger domes using rebar use a temporary 2v wood hub and strut frame, and can be reused to build other domes. This link shows you how to make a simple, easy 2 frequency cardboard dome. For a custom dome diameter, you need to make your own side lengths A and B, side A being .61803 x the radius, and side B .54653 x the radius.

There are basically just 2 gauges of wire or rebar used throughtout the whole dome - a thicker gauge such as 12 gauge wire or 3/8" rebar and a thinner gauge for tying - twist ties (as in making models) or 16 gauge for rebar construction.

Here are the links for assembling the dome along with other pages:
Assembly and materials for 2v and 4v domes (also making circular wire measuring form)
Spreadsheet specifications and instructions
2v geodesic dome diagram
4v geodesic dome diagram
Customized arrangement (with dome pedestal) for your cardbboard dome.
Instructions for bending wire or rebar (for wire-rebar bending, cutting and marking)
Putting it all together...(assembling your 2v wire frame dome model)

Spreadsheet for a 2v diameter wire/rebar dome
Spreadsheet for a 4v diameter wire/rebar dome
Spreadsheet/chart for wire and rebar gauges

On tying rebar vs. hub coupling/connecting: Rebar couplers could be made aligning along different pentagonal planes at the pentagon intersections (even hexagons, and this has been done in design with other spreadsheets), but the general tenesgrity of the dome is still more than adequate with tying. Built to code, Seismic Zone 4 (as in California for earthquakes), the rebar tying overlap specified is about 40-60x in length that of the gauge of rebar connected.

This overlap also is sometimes epoxied over for even further strength. Also concrete or shotcrete is put over the assembled frame in monolithic or solid cast fashion with further compressive and holding strength added. In other words, by tying the overlapping connections vs. coupling helps show that the former is no "hole in the bucket" theory. Concrete walls and foundations in construction for dams and bridges, buildings, structures... also often tie crossing/overlapping rebar. Though as well, once manufactured and already implemented rebar couplers/connectors do have their advantages...

Some more of my links:
Geodesic Math and How to Use It (math book review)
Excavation/landscaping tool reviews/recommendations
Free killer apps for your HTPC... (my personal contribution page)
Free killer apps for your HTPC... (AVS Forum)
What's the big deal about crossovers? (AVS Forum, 4th post down)
Antennas, rotators, boosters/preamps... for wide-band VHF/UHF (AVS Forum)
LaCrosse Technology BC-900 AlphaPower Battery Charger review (12/16/2005)
Webpage on headphones and headphone amplifiers

About Copyrights and Patents for GeoArch Domes:
As far as Copyrights go, feel free to copy and distribute any material on this website - as long as it's not sold for a price... The premise or idea behind this website is to "open-source" as much as I can, so it can be "distributed" as fast as possible... The premise or idea for GeoArch Domes does have protection (though no Patents or Patent Pendings as of yet) - dated material has been copied and sent via sealed/unopened Certified and Registered USPS Mail - as well as protected by MS Office and OpenOffice spreadsheet dated documents...

This web site is a work in progress (if you call enjoyable hobbies work). It is coming along slowly but surely. If you would like to e-mail me with additions or suggestions you can. I'd also like to note that I am not affiliated with any of these companies mentioned above in any way, shape or form.

Last updated 4/4/2011

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