Sea-Gull ST2130

Description

The chinese caliber Sea-Gill ST2130 is an (almost) 1:1 clone of the swiss ETA 2824-2, an 11 1/2 ligne selfwinding movement with date indication.

Even though it can technically keep up with the aforementioned ETA model, it unfortunately overshot the mark and, unnecessarily, became a fake by adding a rather poorly executed “ETA” engraving!

Nevertheless, the movement is shown here, since technically is it really good, and maybe there will also exist versions without the fake engraving.

The gear train is identical to its original: large mainspring barrel, large third wheel with thick axle, small third wheel, central seconds wheel, and escape wheel.

Since there is no center minute wheel, the hands are driven on the dial side by the gear of the third wheel.

The Sea-Gull ST2130 even has got a hacking function to stop the balance wheel, when the crown is pulled out.

Apart from some parts being a bit more crude executed, the overall execution is flawless. There is even one additional jewel, on the movement side bearing of the mainspring barrel.

The balance wheel is a three-leg annular balance, mounted in a pair of Chinese shock absorbers. While it is visually reminiscent of an ETAChoc or Novodiac, it reveals itself as a copy because the cap jewel spring mount has only one recess instead of the original’s three.

The balance wheel beats fast with 28800 A/h, guaranteeing excellent accuracy. The adjustment mechanism is also a copy of the Etachron system, i.e., an eccentric regulating mechanism.

The lever is truly ugly, a very simple stamped part, which is especially noticeable on the lever fork. It’s hard to believe that this isn’t a technical disadvantage, as the ST2130’s accuracy is on a chronometer level!

Typical of both the original and the clone are the rather coarse crown wheel and the significantly more delicate ratchet wheel. The latter engages the final reduction wheel of the selfwinding mechanism.

In the Sea-Gull selfwinding mechanism, all gears are jewel-beared, but they are also significantly more coarsely constructed, as can be seen, for example, in the cutouts on the two change gears.

The two changer gears engage with the oscillating weight on their upper side and with each other on their lower side. Depending on the rotor’s direction of rotation, one of the two pawl changers runs idle, while the other provides a connection between the upper and lower gears. In this way, the following first reduction gear always rotates in the same direction.

Since the two pawl axles of the two change wheels are ruby-beared, the selfwinding mechanism has a total of 10 jewels. Together with the one additional jewel in the upper barrel bearing, the Sea-Gull ST2130 should have 28 jewels.

The oscillating weight, in which the inner and outer parts are somewhat roughly connected, is mounted on ball bearings.

On the dial side, the pinion of the third wheel, which drives the minute wheel on the dial side, is clearly visible at position 8 o’clock, relatively close to the center. The cannon pinion is mounted on it, connected by a slip clutch.

Technically comparable, but visually quite different in detail, is the ETA-typical yoke winding system, where extreme caution must be taken not to press the setting lever too deeply (always use a screwdriver with the correct blade length to press it in!).

The Sea-Gull ST2130 features a quick date adjustment on the middle crown position.
At position 3:30, you can see the gear wheel used for this adjustment, with its three-pointed star.

One final difference from the ETA 2824-2 is the printing of the date ring. The Chinese movement uses a significantly thinner font.

Timegrapher result

An NOS movement, well oiled, which performes really well on the timegrapher after an adjustment.

Technical data