written by Rene K. Mueller, Copyright (c) 2006, last updated Mon, October 8, 2012
Fri, May 5, 2006: Extensions such as skylight, door construction and alternative bows, and photos of a model construction.
Tue, April 18, 2006: Added general calculator (simple one), plus canvas calculator, along with more detailed illustrations.
Tue, April 11, 2006: First version, first calculator, and simple construction plan
Star Dome Model (with bamboo sticks)
While I was researching the net for bamboo based domes, I came across the Star Dome website. a project of the Kyushu Fieldwork Society, in particular
Daisuke Takekawa (Ph.D.) Professor of the University of Kitakyushu, and decided to give a try.
I did a small model, as I usually do when I explore a new form, and I'm very pleased so far, especially since the door can be done easily at the larger triangle at the base, and all bows are the same length, and the position of the junctions is simple to calculate.
According Star Dome, he developed it from a 2V geodesic dome, and finally used 3 bows from each bottom point of the 10 sided polygon.
Star Dome (virtual model)
Star Dome, top view (virtual model)
The main advantage over the 2V geodesic dome is apparent:
15 (or 30 half) bendable struts (optional add 2 for the base), all the same length
no connectors, no complicate calculations (e.g. to reduce waste)
simple bow crossings, which can be tied with cords to provide stability
Star Domes at Night (courtesy StarDome.jp) 2006/04/17 09:54
Star Dome Gathering Space (courtesy StarDome.jp) 2006/04/17 09:55
Star Dome grown green (courtesy StarDome.jp) 2006/04/17 09:54
As mentioned you need 15 full length bows, or 30 half length bows (tied to one long at a time), and drill a few holes to keep the bow crosses stable, or at least mark the crossings in case you plan to tie them:
Step by Step:
Star Dome Construction: Step 1-4
compose a pentagram with 5 bows (blue), and
then a surrounding pentagon with 5 bows (green), junctions at the marks
prepare the base (red), 10 positions
lay the pentagon/pentagram composition over it, and connect the bows accordingly:
those bows whose ends connect another one, cross them
loose ends bend so the final bow goes around the center
Star Dome Construction: Step 5
finally use the remaining 5 bows (blue), look at each base connector, and connect there V (two bows go up) is leaning to left, connect right, and where the V leaning right, connect left.
Optionally 5 bows of l/2 length can be used to cross over the top pentagon, and attached to the new formed pentagones around the side (not yet illustrated, but part of the original construction procedure mentioned above), it's suitable in case you plan no skylight.
The "original" star dome is made from split up bamboo, 10cm diameter and then split into 4 struts. Note: It's not sufficient to split it just once as the bamboo is too strong, must be twice splited (1/4th).
circumference c = s * 10
diameter d = s * 10 / π
bow length lbow = c / 2
floor area afloor = (d / 2)2 * π
surface area asurface = (d / 2)2 * 4 π / 2
volume vtotal = (d / 2)3 * 4 /3 π / 2
a = s * cos(π / 5),
b = s * sin(π / 5),
c = s * cos(π / 10),
d = s * sin(π / 10),
e = s * cos(π / 3),
f = s * sin(π / 3)