4V 3/8 sphere geodesic dome
Class I icosahedral breakdown, cut snapped to the nearest vertex ring (achieved portion 37.4%). 190 struts in 6 lengths, 71 hubs, 120 panels. Strut length = chord factor × sphere radius.
Open this geometry in the studio
Struts
| Strut | Qty | Chord factor | 12 ft dome | 16 ft dome | 20 ft dome | 24 ft dome | 30 ft dome | 40 ft dome |
|---|---|---|---|---|---|---|---|---|
| A | 30 | 0.25318 | 1' 6 1/4" | 2' 0 5/16" | 2' 6 3/8" | 3' 0 7/16" | 3' 9 9/16" | 5' 0 3/4" |
| B | 50 | 0.29453 | 1' 9 3/16" | 2' 4 1/4" | 2' 11 5/16" | 3' 6 7/16" | 4' 5" | 5' 10 11/16" |
| C | 30 | 0.29524 | 1' 9 1/4" | 2' 4 5/16" | 2' 11 7/16" | 3' 6 1/2" | 4' 5 1/8" | 5' 10 7/8" |
| D | 20 | 0.29859 | 1' 9 1/2" | 2' 4 11/16" | 2' 11 13/16" | 3' 7" | 4' 5 3/4" | 5' 11 11/16" |
| E | 40 | 0.31287 | 1' 10 1/2" | 2' 6 1/16" | 3' 1 9/16" | 3' 9 1/16" | 4' 8 5/16" | 6' 3 1/16" |
| F | 20 | 0.32492 | 1' 11 3/8" | 2' 7 3/16" | 3' 3" | 3' 10 13/16" | 4' 10 1/2" | 6' 6" |
| Total | 190 | 337 lin ft | 449 lin ft | 562 lin ft | 674 lin ft | 842 lin ft | 1,123 lin ft |
Cut lengths are hub-centre to hub-centre; subtract your hub's offset at each end.
Hubs
| Valence | Qty |
|---|---|
| 6-way | 45 |
| 5-way | 6 |
| 4-way | 10 |
| 4-way (base) | 10 |
| Total | 71 |
Panels
| Signature | Qty | Area (unit R) |
|---|---|---|
| AAC | 30 | 0.0304 |
| BBC | 25 | 0.0376 |
| BDE | 40 | 0.0394 |
| EEF | 20 | 0.0434 |
| FFF | 5 | 0.0457 |
| Total | 120 | 4.525 |
Proportions (per foot of radius)
- Height 0.749 × R · floor diameter 1.936 × R
- Surface 4.525 × R² · floor 2.943 × R²
Computed by DomeSketch from the icosahedral geometry; the 2V/3V/4V values match the published tables and the test suite asserts it.