- Modern micro-rotor movement
- 4Hz, 40 hours power reserve
The Hangzhou 5000A I have came in a Lobini watch and I was unable to extract the movement from the case, which is why there are no pictures of the under-dial side. The movement is well finished with circular côte de Genève. However, some screws were getting damaged while being unscrewed as the metal seems to be of low quality and the screws were too tight.
The rotor is not held by its central screw, but by 3 screws attaching its base to the rest of the movement. Once the micro-rotor is removed, we can see a bridge holding two reverser wheels as are common in ETA movements.
There are a series of gears that link the micro-rotor to the mainspring barrel. Most of them run under the micro-rotor and the base of the barrel bridge. There is one pinion, seen at the centre of the picture above, that links the gears that are under the level of the barrel to the underside of the barrel bridge.
The jewel at the edge of the bridge (centre of the picture, in line with the crown stem axis) is the one that holds the pinions that links the gears close to the mainplate to those seen on the underside of the barrel bridge. The gears seen here are the ones which will wind the barrel.
It is important to note that there is no central wheel, the minutes are indirectly driven by the second wheel that reaches to the dial side of the movement and the seconds are directly driven but in a sub-dial at 8 o’clock on the dial side.
This setup allows for a 16.5mm micro-rotor or roughly 55% of the 30mm movement.