The base is the cylindrical lower section of the solarium
Requirements[]
- It is a cylindrical shape that must have the same diameter as the dome that will be put on top of it, currently 9'.
- It must be 3' tall.
- It must be able to hold the weight of the metal geodesic dome
- It must be able to support people inside sitting against the walls
- It must be constructed in a way that allows it to be easily partially deconstructed for storage and transport
- It must provide a way to secure it to the playa with rebar
- It must have an door (of reasonable width)
- It must be solid/covered (i.e. a solid wall rather than an open frame.)
- It must have room for a deep cycle battery some electrical equipement someplace
Implementation[]
A side view of one frame showing width height and cross brace length.
Since the dome is a 3 frequency geodesic dome, it means that there will be 15 segments along the bottom. To mate more easily with the dome, the plan is to create 15 wall segments that will connect together and align with the bottom segments of the dome.
One tricky part is that the dome segments are two different lengths and alternate between the two. Given a dome with a 4.5" radius, the dome calculator gives bottom lengths of 21.79" (21 13/16") and 18.82" (18 13/16").
The dimensions in the sketch are in feet (and the width mislabeled as inches) but the idea is to create a frame with 2"x4"s with a cross brace through the middle. Each side will be covered with plywood.
Cutaway view of the bottom of the frame showing rebar holes
The bottom of each frame should have holes to allow rebar to be pounded through and into the ground. The holes should be at a 45 angle so that the rebar can be pounded in (and later extracted) without hitting the cross brace. Additionally some kind of metal plating (tin?) should be put over the wood (with matching holes) so that we can extract the rebar without splintering the wood.
Three sections of the cylinder and where the 4.5' radius dome will meet. 'a' is the inner radius, 'b' is the middle radius and 'c' is the outer radius
The framing will meet at the corners. If the width of each frame is exactly the right widths (21.79" and 18.82") the 9' radius we want will actually be along the inside of the cylinder and the dome top will be very close to falling within the structure rather than sitting on top of it. So, we should probably make the frame widths slightly smaller so that the inner radius ('a' in the sketch) of the cylinder is a little less than 4.5'. Ideally the inner radios it would be 2" smaller. Entering 52" rather than 54" into the calculator gives 18 1/8" and 21" or just 18" and 21".
Measurements[]
Entire Structure[]
Wooden base with first row of conduit (silver bars). Blue sections are Frame "A", yellow sections are Frame "B"
- Height
- 42"
- Diameter
- 108" (9')
Frame Section A[]
- Height
- 42"
- Inner Height
- 39"
- Width
- 21 1/4"
Frame Section B[]
- Height
- 42"
- Inner Height
- 39"
- Width
- 21 3/4"
Lumber[]
Assuming 10' long 2" x 4"
- 39" Lengths
- 15 * 2 = 30
- 3 per 10', 10 beams needed
- 21 1/4" Lengths
- 5 * 2 = 10
- 5 per 10', 2 beams needed
- 21 3/4" Lengths
- 10 * 2 = 20
- 5 per 10', 4 beams needed
Plywood[]
Assuming 4' x 8' (48" x 96") sheets of plywood
- Frame A face
- 42" x 21.25"
- 4 faces per sheet
- 2 sheets
- Frame B face
- 42" x 21.75"
- 4 faces per sheet
- 3 sheets
- Cuts per sheet
- 5
- Cuts total
- 25