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My geodesic dome had as base the article Geodesic Domes for Amateur Observers, S&T October 1994, p. 90 and it corresponds to the specifications of Dodecahedron.

I make in first place a model in cardboard .This allowed to choose the best way of the set up and, decide that for my case was the construction of the inferior part of the dome.

I thought initially to use the marine plywood as described in Sky. It was heavier, more expensive and less durable. I spoke to J. Garcia and, he advised me to use foil zinic that was what had used in its observatory.
In its construction I used 10 foils zincked of 0,8 mm. The lateral wall it is set up by 18 triangles isosceles and 12 means isosceles triangles , the top for a hexagon of 6 triangles.

They were built six modules of 3 complete triangles and two alf initially. To connect the faces bars of aluminum 20 x 4 mm on both sides were used with previous perforation, after was made identical perforation in the boards of the foils. Finally after application of silicon I riveted all pieces. In the union of the modules bars of aluminum of 40 x 4 mm. In cover was used same process.

The test assembly was made in the soil, as well as the section of the opening for observation with 570 mm.

Later mounted the 6 modules in the definitive place.

Then I order to iron-worker’s workshop the making of the two rings with 2.47 m , the inferior in U and a superior in L. The first is the guide.

The casters (6) are fix to the L and support the dome .

This is to more difficult part, because the workshop in Portimão was damaged and had take time to repair.

The casters that I obtained had rubber wheels and they didn't tolerate the friction and the weight. A turner friend turn me anothers in celuron.

The whole structure took a painting with a primary anti-rust Colorex S and therefore the normal inks for external.

Later  a problem that took time to solve, was the water that condensed in the interior of the dome (shelter) due to the external coolness especially during the night, arriving to let de drops fall. I tried an suction fan and a fan but little effect had.

Finally the miraculous solution: a deshumidifier in the dry and working of middle of the night to the morning.

With relationship to the dimensions:

Interior diameter in the base of the cupula 2,60 m

Height of the center the platform = 1,75 m

Dimensions of the terrace in that meets the installation: 2,40 X 2,O

X 3,O m.

Wood platform to 1,3 m of height with 2 X 2,10 m.

Pillar of hollow iron of 11 cm of diameter with 156 cm of length that serves as support to LX 50,

fixed to the soil with 4 scouring pad screws.

Plus some images on the building:


 
 
 

Instruments and Accessories of the Observatory