| Year | 2005 |
| Date | 04-Feb |
| Volume | 194 |
| Issue | 4,240 |
| Page | 142 |
| Category | General |
| Part | 5 |
| Title | Paradoxical Gears (A new challenge; Intriguing Object) |
| Author | Jacques Maurel (France) |
| Notes | How to make a true involute gear set with standard milling equipment. Material, principle of machining, explanation, machining process for the left-hand helix gear, machining process for the right-hand helix gear, result, tie break |