Faceting Equipment
From The Gemology Project
Overall Equipment List
Faceting Machines
Types of Machines
Mast Type
Platform Type
Quadrant Type
Portable (Hand-powered)
Setting up the Machine
Adjustment & Maintenance
Necessary Tools
Articles on Adjustment & Calibration
Machine Accessories
Dops
Index Gears
| Gear | Symmetries | How Common | Angle Between Gears | Notes |
|---|---|---|---|---|
| 120 | 3, 4, 5, 6, 8, 10, 12 | 135/4307 = 3.1% | 3 | This is also an important gear. It produces a lot of the same symmetries as the 80 gear, but with more teeth. Many specialized designs are produced for this gear because allows the most index settings. |
| 108 | 3, 4, 6, 9, 12 | 0 | 3.33 | This gear would only be for custom designs. Capable of producing 9-fold symmetry. Most manufacturers do not even produce this gear |
| 96 | 3, 4, 6, 8, 12, 16, 24 | 2812/4307 = 65.3% | 3.75 | This is by far the most common gear used. It contains a large number of symmetries. It can reproduce all designs produced for a 32 gear by multiplying by 3. It can produce some designs produced for a 64 gear, as long as those designs only use the even numbered teeth – in which case you multiply by 1.5. |
| 88 | 4, 8, 11 | 26/4307 = 0.6% | 4.09 | Capable of producing 11-fold symmetry. Very rarely used. |
| 84 | 3, 4, 6, 7, 12 | 13/4307 = 0.3% | 4.29 | Capable of producing 7-fold symmetry. Very rarely used. |
| 80 | 4, 5, 8, 10 | 319/4307 = 7.4% | 4.5 | This is one of the more important gears, especially for 5- and 10- fold symmetries. |
| 77 | 7, 11 | 3/4307 = 0.1% | 4.68 | Capable of producing 11-fold symmetry. Very rarely used. |
| 72 | 3, 4, 6, 8, 9, 12 | 11/4307 = 0.3% | 5 | Capable of producing 9-fold symmetry. Very rarely used. |
| 64 | 4, 8, 16 | 770/4307 = 17.9% | 5.625 | This is common in older designs. Although it shares a lot of same symmetries with the 96 gear, they are not completely interchangeable because only the even teeth on the 64 are reproducible on the 96. This gear can handle any design produced for a 32 gear by multiplying the 32 numbers by 2. |
| 60 | 3, 4, 5, 6, 10, 12 | 13/4307 = 0.3% | 6 | This gear shares the same symmetries as the 120 gear. All of its designs can be produced on the 120. |
| 32 | 4, 8, 16 | 82/4307 = 1.9% | 11.25 | This gear shares the same symmetries as the 64 gear. All of its designs can be produced on the 64. However, because of the smaller number of teeth, there is less likelihood of error do to mis-indexing a cut. |
