China DG38xx?

Description

Chinese movements had a bad reputation, especially in the past, because they were often installed in counterfeit watches in the cheapest possible versions.

One such example is the movement presented here, which can no longer be clearly identified, but presumably comes from the Mingzhu factory and belongs to the DG38xx caliber family. With the date display at 6 o’clock, it could also be suffixed with “-6D” and might perhaps be a DG3836-D6.

It has got a diameter of 11 1/2 lignes and reminds in its construction a bit of a Citizen/Miyota 82xx.

The base plate is very crude executed, but has synthetic rubies at all important bearings. These rubies are all flat and therefore have little ability to retain oil.

We have the classical gear train with a center minute wheel, directly driven by the mainspring barrel.

Not only the gear train for the time display, but also for the selfwinding mechanism is located entirely on the base plate and under a single bridge. This is really not service-friendly.

The gear train for the time display consists then of the third wheel, which simultaneously indirectly drives the central seconds pinion and directly drives the seconds wheel, followed by the escape wheel.

As balance for the pallet lever movement, a simple four leg anular balance is used, which is beared in a pair of chinese shock protections, which look a Duroswing.

It beats semi-fast with 21600 A/h and can be adjusted at the hairspring key only.

The gear train for the selfwinding mechanism consists of only two parts, a reduction gear and a clutch wheel.

The clutch wheel is driven by the oscillating weight on the top side and engages the bottom side and the pinion via a clutch. The pawl engages this bottom side, creating a one-way selfwinding mechanism.

The clutch is presumably a ratchet clutch, but unfortunately it is impossible to say for sure without destroying the clutch wheel.

The oscillating weight is ball beared; beneath it, on the inside of the gear train bridge, is a leaf spring that applies friction to the indirectly driven center seconds pinion and prevents the second hand from fluttering and jumping.

Between the crown wheel and the ratchet wheel is a sliding transmission wheel, which creates a frictional connection between the crown and the ratchet wheel during manual winding and disengages the crown during automatic winding.

The oscillating weight is more or less a simple stamped metal part with a D-shaped recess for the axle. The outer ring is riveted.

The date mechanism switches slowly, but has got a quickset ability, using the middle crown position. This is achieved by the (in the photo dislocated) lever above the yoke winding mechanism.

The further calendar mechanism is mounted on a separate plate, which is screwed onto the dial side.

It is driven by the hour wheel and consists of a weekday display (hand) at 9 o’clock, a 24-hour display at 6 o’clock (not used in this example), and a month display (also by a hand) at 3 o’clock.

The entire mechanism, including its correction and other levers, is under tension and is therefore almost impossible to maintain.

The month display at 3 o’clock is funny: it doesn’t advance at the end of the month (it wouldn’t be possible anyway, since there’s no connection to the date ring), but instead has to be advanced with the help of a pusher. Technically completely useless, but at the time, it was easy to equip fake and cheap watches with as many hands as possible.

The calendar mechanism is covered by a metal cover plate, on which subdials are printed. Despite this rather unique design, this didn’t help with identification.

In the lab

Timegrapher result

The timegrapher rates are poor, which is certainly not only caused by the long wear.

Technical data

Usage gallery