An exciting new art form.
Geodesic domes and spheres are eye-catching and attention getting. Curiosity stimulates the mind to consider how domes are made and the principles and actual industry involved in construction. This discovery begins with Nature and how we analyze and use it, travels history from Plato to Euclid (c. 325-265 B.C.), Archimedes (c. 287 B.C.-212 B.C.), Descartes (1596-1650), Euler (1707-1783), to Buckminster Fuller and his development of Geodesics and Synergy.
Star Dome Geo-Sphere
This sphere I made from 3/4″ diameter steel tubes. The design is the “Star Dome 1-A” type.
The diameter is 7 feet. Much larger spheres and domes are made in the same fashion.
Click on these thumbnail images for a larger view.
TWELVE STARS JOINED
Some facts about the Star Dome 1-A sphere:
1. The 12 stars are made from 60 tubes- 5 tubes bent strategically and drilled for attaching make up one star. (15 struts each, total 180 struts). These make 10 geodesic “great circles”.
2. 60 tubes make up the Star Centers and half of the struts in the hexagons between the stars (total 120 struts).
3. 30 tubes make the final struts that complete this sphere (total 60).
4. The complete sphere is made up of 150 separate tubes, that make up the 360 struts.
5. It was all fabricated with simple tools including a manual hydraulic press and drill press (we now use an electric hydraulic 40 ton press), and took 2 weeks to measure, saw, flatten tube ends, drill holes, etc.
6. It was a prototype resulting in a very strong sphere structure. Several Geo-Spheres of various types from 3 to 12 ft have since been constructed.
Excerpt from Geodesic Math and How to Use It by Hugh Kenner
“In what we may call the prehistory of the art, there were no [geodesic division] breakdown systems at all. Buckminster Fuller’s first experimental domes were simply sets of icosahedral great circles, made of short chord members bolted together. All thirty-one great circles made a structure of enormous strength, and they intersected one another so frequently that the maximum component length was never excessive (about 9-1/2 feet for a 50-foot-diameter structure). Still, disadvantages of the structure strike the eye: components lengths vary over a range of more than two to one, and so does vertex population….It is intuitively obvious that such a system contains much redundancy…” (page52)
But then other advantages are described:
“The geodesic dome, as we have seen, is supported by tension, and the tension networks are most economical when their strands run for considerable distances without changing direction. This means aligning sequences of vertices along great-circle arcs.” page 70-71
Note: Buckyworks by J. Baldwin contains a photograph of Bucky next to one of these early great circle domes.
a 2 frequency octahedral Geo-Sphere.
Any polyhedra or geodesic can be a Geo-Sphere, from simple to complex, and generally priced according to tube size and qty. of parts. Copper, stainless steel or other metals can be used.
Some other photos:
can be constructed into domes and Geo-Spheres.
The Geometry Center, University of Minnesota site
shows several polyhedra with mid-edge and in-centers of faces joined.
These become geodesic great circle dividing lines and in the case of building structures,
triangle strength is added.
For instance the first image is the dodecahedron, which projected to the sphere surface becomes the Dodeca-Dome