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| The B cross consists of two B members whose lengths are: 1/2 BB plus 1/2 BR plus 12" extra at each end. | The R cross consists of two R members whose lengths are: 1/2 BR plus 1/2 RR plus 12" extra at each end. |

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| Place members at right angles to each other and tie firmly, but not too tight. During assembly of the dome, the crosses will twist into proper position as shown. | |
| In all cases, when looking at a cross with the acute angles at the sides and the obtuse angles at the top and bottom, the member going from the upper right hand corner to the lower left hand corner always passes over the other member. | |

| Step A: Tie together two B crosses as shown in in the diagram. Note that the end measuring points have the same designation as the cross to which they are connected. (By "end measuring points", the ends by which the cross is connected to other crosses are meant. In this case B-ends connected to B-crosses.) | ![]() | |
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Step B: Add two more B crosses in the same manner as shown in step A. | |
| Step C: Add fifth B cross between the untied legs. In order to insert this cross, all crosses will be twisted so that a regular pentagon is formed. (So all connections have to be B-on-B, otherwise the pentagon is not regular.) | ![]() |
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Lift the assembled figure off the ground to facilitate the addition of new crosses. Use five bi-ped props. Each prop consists of two bamboo sticks about 7 feet long, tied together near the top with a cord about a foot long. These props will then support the dome at equidistant points from it's apex; first at the five vertices at the top of the pentagon, later at five corresponding points on the top five hexagons. If you are building only a small dome, you can just lay it upside-down. |











| © 2002 Desert Domes | info@desertdomes.com | Oakland, California |
| Additional info by Marnix Arnold | MxA's Dome Blog | Amsterdam, The Netherlands |