PC 13.029B
Tri-Curve Spike 72
- L/W
- 103%
- Design RI
- 1.54
- H/W
- 61%
- Gear
- 72
- V/W³
- 0.204
- Symmetry
- 3 (mirrored)
- Facets
- 79
- Tiers
- 15
- Crown
- 37
- Pavilion
- 24
Based on Star Cuts I (1980) p27. Index 72 mentioned but cutting instructions not given.
Wireframe
Pavilion
| # | Angle | Facets | Notes |
|---|---|---|---|
| G1 | 90.00° | 71731415565 | From preform PF13029B |
| G2 | 90.00° | 51929435367 | From preform |
| G3 | 90.00° | 12325474971 | From preform |
| P1 | 42.26° | 12325474971 | Meet P1-G2-G3 |
| P2 | 41.51° | 51929435367 | Meet P1-P2-G2-G3 |
| P3 | 41.00° | 32127455169 | Cut to PCP |
| P4 | 40.81° | 71731415565 | Meet P1-P3-P1-P3 |
Crown
| # | Angle | Facets | Notes |
|---|---|---|---|
| C1 | 40.00° | 12325474971 | Fix girdle thickness. |
| C2 | 40.00° | 51929435367 | Level girdle |
| C3 | 40.00° | 71731415565 | Level girdle |
| C4 | 35.00° | 32127455169 | Meet C1-C2-G2-G3 |
| C5 | 30.52° | 123660 | Meet C3-C3-G1-G1 |
| C6 | 26.51° | 722448 | Meet C1-C5-C5-C1 |
| C7 | 23.99° | 71731415565 | Meet C5-C2-C3-C4 |
| T | 0.00° | 72 |