Technical sheet
The Co-Axial Master Chronometer Moonwatch calibre: hand-wound, free-sprung, stop-seconds.
Features
Going train
| Arbor | Wheel | Pinion | True speed |
|---|---|---|---|
| Mainspring barrel | 78 | — | 1 rev / 6.5 hours |
| Center wheel | 80 | 12 | 1 rev / hour |
| Third wheel | 75 | 10 | 8 rev / hour |
| Fourth (seconds) wheel | 72 | 10 | 1 rev / minute |
| Escape wheel | 15 | 6 | 12 rev / minute |
Disclaimer
An approximation of the Omega 3861 layout from public drawings and photographs, not a manufacturer-accurate replica. Manual winding, 21,600 vph (3 Hz), 50 h power reserve, 26 jewels, Ø 27.00 mm, 6.87 mm height, Co-Axial escapement, free-sprung balance with silicon (Si14) balance spring, METAS Master Chronometer certification (15,000 gauss), rhodium-plated finish with straight Geneva waves, stop-seconds, a cam-operated chronograph with horizontal clutch, small seconds at 9, 30-minute recorder at 3 and 12-hour recorder at 6 are published figures. The Co-Axial principle (two-level escape wheel, three-stone pallet, impulse roller) is documented but its exact geometry is not: the escapement is illustrative. Tooth counts, wheel sizes, bridge outlines and the chronograph parts are an approximation. The escapement and chronograph motions are kinematic models.
Sources