Technical sheet
Citizen’s thin 4 Hz automatic: center seconds, date, a ball-bearing rotor.
Features
Going train
| Arbor | Wheel | Pinion | True speed |
|---|---|---|---|
| Mainspring barrel | 66 | — | 1 rev / 5.5 hours |
| Center (minute) 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 Miyota 9015 layout from public drawings and photographs, not a manufacturer-accurate replica. 28,800 vph (4 Hz), 24 jewels, approx. 42 h power reserve, 11½‴, Ø 26.00 mm and 3.90 mm height are Miyota’s published figures (Monochrome gives 25.94 mm and Grail Watch Reference 25.60 mm; Miyota’s 26.00 mm is used). The sources consulted do not name the escapement type: the 3D lever escapement is a generic illustration. Tooth counts, the barrel and train positions and the shapes of the bridges are an approximation; the tooth counts give the published rate and a seconds wheel turning once a minute. The real rotor winds in one direction only; the shared animation winds on both swings. The escapement motion is a kinematic model, not a physics simulation.
Sources