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New Asian copy of the ETA 7750 |
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Articles -
Watchmasters Corner
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Written by Ziggy Zumba
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Page 3 of 7
I should add that the reason the movement was sent in at all, was because it did not wind in the auto mode, if you wore it, after a while it would stop working. Hand winding would let it run for 36 + hours but no automatic wind…what was the problem? Well as soon as the case back came off, the rotor fell to the floor, come to find out the rotor is broken off of the bearing. This can happen, and I am simply replacing it with a new one…
The owner decided to have the watch serviced along with the repair, and that is a good idea, at least he has a known condition of the watch when it leaves the shop and can expect 5 years before needing another service. Given the spotty history of the Asian 7750’s, servicing is an investment in the long run.
Not only is the quality of the overall movement impressive, once I tore into it in detail, it had more surprises for me.
If you remember my initial teardowns on these models, everyone had a few common problems, dirt, lack of oil, and a crappy cannon and 12-hour wheel. Neither the cannon or 12-hour wheels are lubricated, but even more problematic is the fact that the cannon wheel doesn’t have enough friction, which shows itself by the time on the hands running behind, but the seconds being accurate. For more details on this, see my previous posts.
On every Asian 7750 I service, I have to put the cannon wheel on the jewel press, and compress part that holds the clutch in place to increase the friction. This is not easy and can result in some surprises, on one job, the cannon wheel disintegrated when the press slipped and touched the side of the gear…ah the stories I could tell…
Improved cannon pinion
The cannon pinion on this one is dry (no change there), but had as much friction as an ETA 7750, I was shocked as this has always been a big issue. Check out the quality of the clutch part of the cannon pinion, well crimped and 100% better than the old ones, so this is one big problem fixed – finally (ETA Cannon wheels are not interchangeable with the Asian ones, if they were I would not be fixing them myself…).
Now the rest of the parts look as good as any ETA, I see no reason for any problems with regular servicing and maintenance.
More detailed pictures
Here are some various detail shots.
This is the mainspring barrel seat area on the motion works bridge
here is the mainplate with from top left to bottom right, the mainspring barrel, the 4th wheel, 3rd wheel, 2 wheel and the escape wheel…
keyless works and the hacking lever on the right side…
Close up of the gear on the mainspring barrel that drives the 12-hour counter on the dial side…
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Last Updated ( Tuesday, 14 August 2007 )
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