Photo Credit – Michael Millette & Zip Tie Domes
Truncating a 3 Frequency Icosahedron
To truncate is to cut something off.
Form and function are two starting points of knowing where to cut a portion of the icosahedron off with the intent to make a home.
Form includes your personal vision and what you require for the space. Functionality is how you plan to use the space and how the internal environment and external conditions relate to each other.
Do you want your dome to be one open space or have a second floor?
Do you want a low, medium or high profile dome?
Knowing this will help you know how to fraction the icosahedron in parts to then remove a portion of it, to create a base.
8ths or 9ths?
However, in the dome world it seems that domes are fractioned into halves, eights or ninths.
It’s not a perfect system, but when dividing the icosahedron into parts – some say 8ths, other 9ths. More confusing is that it is only 8ths when it is 5/8ths or 5/9ths. No-one says 3/9ths, they only say 3/8ths.
Some dome people say it is technically accurate to say 5/9ths.
It is not an exact science.
Below are examples of truncated icosahedrons:
Photo Credits – Geodesic Dome Plans
Form and Function
As we started designing our dome home, there were very specific aspects we wanted included in it such as a central, large standing stone fireplace, a loft overlooking the open space below with a contemporary, wooden spiral staircase leading up to it.
Therefore, we would want a 5/8ths – a higher profile – to accommodate us. But, you can make a two level dome in a 1/2 or 3/8ths by making a larger diameter dome – it has nothing to do with the frequency. Remember, frequency makes a dome rounder – it doesn’t effect the size. Size has to do with the radius or diameter. But, you don’t want the struts to be too long so that they can’t do their job. When it comes to that point, then you would increase your frequency. Or, you use materials strong enough to maintain the structure.
All sorts of structures can be built as domes: from grand homes, to chicken coops and interesting greenhouses!
The possibilities are endless! We’re even planning to build a dome stable for horses with a Reiki studio loft above it! This dome will have a horizontally inclined elliptical configuration.
Exciting stuff, ‘eh!