6V 5/8 sphere geodesic dome
Class I icosahedral breakdown, cut snapped to the nearest vertex ring (achieved portion 58.9%). 645 struts in 9 lengths, 226 hubs, 420 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 | 0.16257 | 11 11/16" | 1' 3 5/8" | 1' 7 1/2" | 1' 11 7/16" | 2' 5 1/4" | 3' 3" |
| B | 60 | 0.18191 | 1' 1 1/8" | 1' 5 7/16" | 1' 9 13/16" | 2' 2 3/16" | 2' 8 3/4" | 3' 7 11/16" |
| C | 30 | 0.18738 | 1' 1 1/2" | 1' 6" | 1' 10 1/2" | 2' 3" | 2' 9 3/4" | 3' 9" |
| D | 30 | 0.19048 | 1' 1 11/16" | 1' 6 5/16" | 1' 10 7/8" | 2' 3 7/16" | 2' 10 5/16" | 3' 9 11/16" |
| E | 80 | 0.19801 | 1' 2 1/4" | 1' 7" | 1' 11 3/4" | 2' 4 1/2" | 2' 11 5/8" | 3' 11 1/2" |
| F | 110 | 0.20282 | 1' 2 5/8" | 1' 7 1/2" | 2' 0 5/16" | 2' 5 3/16" | 3' 0 1/2" | 4' 0 11/16" |
| G | 150 | 0.20591 | 1' 2 13/16" | 1' 7 3/4" | 2' 0 11/16" | 2' 5 5/8" | 3' 1 1/16" | 4' 1 7/16" |
| H | 75 | 0.21535 | 1' 3 1/2" | 1' 8 11/16" | 2' 1 13/16" | 2' 7" | 3' 2 3/4" | 4' 3 11/16" |
| I | 80 | 0.21663 | 1' 3 5/8" | 1' 8 13/16" | 2' 2" | 2' 7 3/16" | 3' 3" | 4' 4" |
| Total | 645 | 778 lin ft | 1,037 lin ft | 1,296 lin ft | 1,556 lin ft | 1,945 lin ft | 2,593 lin ft |
Cut lengths are hub-centre to hub-centre; subtract your hub's offset at each end.
Hubs
| Valence | Qty |
|---|---|
| 6-way | 190 |
| 5-way | 6 |
| 4-way (base) | 30 |
| Total | 226 |
Panels
| Signature | Qty | Area (unit R) |
|---|---|---|
| AAD | 30 | 0.0125 |
| BBD | 30 | 0.0148 |
| BCF | 60 | 0.0156 |
| EFG | 150 | 0.0177 |
| GGH | 75 | 0.0189 |
| HII | 75 | 0.0202 |
| Total | 420 | 7.348 |
Proportions (per foot of radius)
- Height 1.179 × R · floor diameter 1.968 × R
- Surface 7.348 × R² · floor 3.041 × R²
- Base ring is not flat: hubs differ by 0.0160 × R — plan a stepped base plate or trim the base struts.
Computed by DomeSketch from the icosahedral geometry; the 2V/3V/4V values match the published tables and the test suite asserts it.