Technical sheet
ETA’s thin top-range automatic: 3.60 mm, 4 Hz, center seconds and date.
Features
Going train
| Arbor | Wheel | Pinion | True speed |
|---|---|---|---|
| Mainspring barrel | 84 | — | 1 rev / 7 hours |
| Center wheel | 80 | 12 | 1 rev / hour |
| Third wheel | 75 | 10 | 8 rev / hour |
| Fourth (seconds) wheel | 84 | 10 | 1 rev / minute |
| Escape wheel | 20 | 7 | 12 rev / minute |
Disclaimer
An approximation of the ETA 2892-A2 layout from public drawings and photographs, not a manufacturer-accurate replica. 28,800 vph (4 Hz), 21 jewels, Ø 25.60 mm (11½ lignes), 3.60 mm height, ball-bearing automatic winding, date with corrector, stop-seconds and the ETACHRON regulator are published ETA figures. The 42 h power reserve, bidirectional winding, 51° lift angle and Incabloc shock protection come from Caliber Corner (no ETA figure was found for them). Tooth counts, wheel sizes, the barrel position, the outlines of the bridges hidden under the rotor and the seconds drive are an approximation; the tooth counts make the fourth wheel turn once a minute and the escape wheel match 28,800 vph. Parts are drawn larger than life for legibility and the stack is much taller than the real 3.60 mm. The escapement motion is a kinematic model, not a physics simulation.