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New Asian ETA 7750 Replica Watches

This article comes from Ziggy – a seriously zealous piece about the new Asian copy of the ETA 7750 movement. It’s been done before but this time its even better. The 7750 can be found in Breitling replicas and in the replica Rolex Daytona.

Introduction

Some are saying that recently there’s a new spirit infused into replica watches – a machine spirit known as the Asian 7750, with an ancestor in the ETA 6497-2 “Chinese” copy movement. The Asian 7750 is not a B or B1, but is a whole new breed. Its finish, its fit, it reliability, everything about it will appeal to watch enthusiasts – especially its 8 ticks/sec since it’s a 28,800BPH movement. Let’s take a look at this beauty and discuss what makes it tick.

Notice that this one comes from a Daytona that has at six the running seconds. As I’ve stated before regarding the design of the 7750 at the time the ETA-powered version was released, it seems like it’s just too tall of an order for the movement. Putting eleven gears so you can operate all the subdials is bound to cause headaches and problems. Since I’ve seen many ETA-powered Daytonas in my shop and have not been able to fix them (though I have been able to at least freeze the subdials), I just can’t imagine how the layout can function better what with the fundamental problems between Asian-powered versus Swiss-powered movements. But my tinkering lead to some interesting discoveries.

This movement has some intriguing things going on inside it and I think it will impress you. For one thing, the finish is just incredible in comparison to the 7750B and the 7750B1. This one should probably be called a 7750A+ if you ask me.

When I broke the movement down I found some really well-manufactured components, and no oil whatsoever but in the balance-cap jewels – I’ll explain this later – it is in fact on purpose I think. But there’s just something special about this 7750 – it’s unlike any of the other Asian ones I’ve worked on.

Pictures and Details

Following are pictures and descriptions of what I found inside, which was completely dirt- and fragment-free!

Escape and balance

Winding gears

Auto-wind bridge with pieces

Gears of subdial hands

Plate with transfer gears for subdials

Movement’s dial side with bridge removed

Back of the bridge

Keyless works (see the great finish?!)

Pretty nice-looking. This movement was actually brought in to me was just because it didn’t wind when it was in auto-mode. It just would stop working after some wear. Winding it by hand allowed for 36+ hrs of run time, but the auto-wind wasn’t working. Why? When I took off the case back, the rotor just fell out – it had broken off the bearing basically. So I’m just gonna replace the darn thing and that’s it. That happens sometimes.

The replica watch was also left for servicing which is of course a very good idea – the owners knew what was wrong, could get it fixed, might as well take a look at the rest, and they knew it would be a long before they’d need anything else done to it, so. When you know how troublesome Asian 7750s can be it’s a good idea to do some pre-emptive fixing.

My first breakdowns of these models revealed some common problems always – no oil and lots of dirt, a bad cannon, and only twelve-hr wheels. Nothing was lubed up, and even worse the cannon wheel was way too loose – no friction, which means the hands start to run behind while the seconds are always accurate. You can see my other articles on this.

The Asian 7750s I’ve dealt with have required me to place the cannon wheel on a jewel press and compress the piece where the clutch is mounted to make it more frictional. It’s not a simple thing to do and can lead to some variable results. With one watch I completely obliterated the cannon wheel because the jewel press fell off the table- I was a little distracted that time, but I won’t go into why, hehe.

Cannon pinion improvement

On this watch, the canon pinion isn’t lubricated, like all the other ones, but it had a lot of friction – as much as an ETA 7750. This totally surprised me of course. If you look at the clutch of the cannon pinion you’ll see its superbly crimped and all-around better than any before it. Just a note – ETA cannon wheels can’t be exchanged for the Asian versions – if that were possible, I wouldn’t be in business.

All of the other components are just like any other ETA so I don’t think there should be any issues.

More specific pictures

Below are some other pictures that show off this piece.

Here is motion-works bridge with the mainspring barrel seat.

The main plate, the mainspring barrel piece, fourth wheel, third wheel, second wheel, and escape.

The key-less works and hacking lever on right.

 

Shot of the mainspring barrel gear which moves the twelve hour counter on the dial end.

The banking pins where the pallet arm is, way better than the older 7750s.

This is the dial side, just below the new plate for the transfer gears, this is where the minute wheel, cannon wheel sit (minute wheel goes in the large space on the left)

The dial end, underneath the plate with the transfer gears – here’s where you find the minute wheel and cannon wheel (space on the left is for the minute wheel).

Some shots of the assembly.

Here’s the click wheel, auto-winder rotor clutch. It’s a spring rachet, not likely to have hand-wind issues like the 2836-2 click wheels.

The brass wheel is the center chrono seconds wheel, and that arm beneath is the transfer gear which takes the second wheel seconds to the chrono. Here you see brass with steel which could have some issues.

This is the bottom chrono reset lever assembly with the reset arm, brake lever, and pusher piece. This spring is very difficult to install. All this is for the 12 hour counter.

The bottom chrono with the reset lever assembly and arm and brake lever and pusher. All this is hard to put together to be sure. It’s all for the twelve-hr counter.

General pic just to see how it all relates.

The eleven gears situated before the bridge is set – pretty complicated stuff!

The arrow points out the 30-min timer which centers the spring eccentric screw adjustment. On older models, the screw is backwards and not able to be manipulated. These kinds of details make me think that the replica makers are really paying attention.

This pic shows the center post that goes on the chrono seconds wheel. For some reason the gears in this movement are brass on steel – that reason is they make good friction. With the ETA 7750 it’s a steel tube but here they chose to go with brass.

What’s fantastic is how they put a jewel on the other side where the shaft sticks out and where the second hands connects. The ETA’s don’t do that but somewhere along the line they wanted to affect the friction and extend the movement’s life.

More improvements, note the mainspring barrel, on the ETA and the older Asian models, the barrel is split in the middle. This one is a cap type, much better design in my opinion. Nice long mainspring, smooth barrel sides which is common on the 7750. It was clean, only dry, so I lubricated the sides of the barrel with special high friction grease, and installed the spring and lubricated it with oil.

Check out the mainspring barrel. The ETA and older Asian versions have barrels that are split down the middle. But here, it’s a cap type which is a lot nicer. The mainspring is long, the barrel sides are slick – not uncommon for the 7750. I had to lube up the barrel sides actually with a high-friction substance, then put in the spring and lubed it also.

You see here the jewels of the balance cap – the only oiled thing I found. But they were like this before fixing.

The balance up close.

So – we’re talking about the “running seconds at six” model so it will probably have the same issues as the Swiss-powered models. With maybe too much stress from all the gears. As I mentioned in another review and above, it takes eleven gears.

The problem with transfer gears

The running seconds gear is seen here, which will be matched up with five other gears before the seconds can show at six. Obviously, this will weigh on the movement. It’s constant too – like a beating heart, it can’t just stop to take a breath or something.

The cannon gear is 1, and the running seconds transfer gear is 2 (the shaft at the nine subdial – the second wheel is running seconds), the minute wheel is three, the hour wheel is 4, where the hour hands goes.

I put the movement on the watch analyzer Before installing any transfer gears and adjusted the beat and rate. Here’s what it looked like.

I used the watch analyzer on the movement before I put in the transfer gears and fixed the beat and the rate. See:

I had to move the bridge to the dial then re-tested the beat and timing. That was with one of transfer gears in. It was definitely not looking pretty – so much for one gear to manage that the watch just gave up. That was one gear – just think of three.

If this problem could be fixed it would be in the design department, not anything a serviceman could do. After disassembling the bridge and gears four times, doing an oil change, cleaning, and etc, in the end I pressured the transfer gear from the plate by pulling out the center pin with the trusty jewel press and cleaning it and oiling it again. After reassembly, it finally worked.

Here is the first mentioned gear. The gear on the end of the second wheel is under the gold-colored gear. It matches up to one of five transfer gears which are under the silver-colored plate. This is the problematic one where I removed the pin from.

After using the watch analyzer, I reworked the rate and the beat – the load changed both of them but it was not as bad as it was at first with the heightened friction. The problem seems to have been solved. The gears were reinstalled and the movement’s been working for two days. It’s hard to say what will happen in the future, but even the Swiss movements that I have aren’t perfect. It’s the extra gears – they put too much pressure on the performance.

When I asked the owners, they were ok with getting rid of the running seconds gears, and then freeze the subdial since this’ll make the watch function a lot better and more reliably. Smart move.

When people ask about the Rolex Daytona line, I always saw the same thing – forget about the one with the running seconds hand at six, they’re always a problem. 11 gears in one movement is just too much of a  strain. The movement was meant to handle all that – think of a four cylinder engine being used in a big truck. Sure it’ll actually work but it’ll fail fast. That’s just based on I’ve seen in this trial.

The movement-oiling mystery

Do you recall how I mentioned that in this piece the movement wasn’t oiled? Well now I’ll tell you why. It just didn’t make sense why they’d make this awesome movement and not oil it – except for the balance cap jewels. Oil helps limit the wear n’ tear on mechanical pieces in almost any gizmo because it provides lubrication for the parts that move against each other – that’s oil’s m.o. – modus operandi. But believe it or not, it also makes for a slight bit of healthy friction too. When a jewel turns without being oiled it actually takes less power than when it turns on an oiled pivot. But can’t you over-oil a watch? In what mechanical context could that be true? Are you getting what I am getting at here?

Imagine for a moment a movement that has eleven gears – so chockfull it could possibly bust. You want as little friction as possible in there, and even though you know, as the watch maker, that friction comes from dry surfaces, you also know that friction can come from oil, so it’s a 50-50 shot, and you test both, and you realize that if you don’t oil it, it works for the best, and it’s even cleaner. I have no idea I’m just making an educated guess here, but it makes sense to me. Otherwise, why no oil?!

Without eleven extra gears in there, it’s an amazing replica of a 7750. Way better than the previous versions, no doubt about it. If I could, I’d replace all the movements of all my watches with this baby.

What’s more? The seconds chrono hand is like butter, just like the OEM model, running at 28,800 BPH.

If I had my druthers, I’d probably just jimmy out the running seconds gear, freeze-pop the six counter, and let the watch tick on forever with peace on my mind. Why? Because the extra five gears are actually too much work for the movement if you ask me. But I’m not the designer you understand, I’m just the serviceman, I can’t re-make the movement, so I’ll adjust it. I can see that the watch will have issues in the problem, maybe even stop entirely, so I’ll pop out that piece and simplify, simplify, simplify, people.

Summary

Once you appreciate the reality of the situation, the retooling was pretty straight. I did accidentally oil the watch out of habit once, and you could tell that the movement’s available power had a limit. When I put in the last bridge with that extra gear, I heard this grinding sound that foreshadowed the movement coming to a halt. It took me over two hours to deal with the extra transfer gears, at which point I pulled off the pressed gears and gave them a good scrub and just a hint of oil before putting it all back together. I triple-checked the pins’ clearance so there wouldn’t be any extra friction, and that was about it folks. The movement now runs smoothly with all the gears where they should be, but it might stutter once in a while forever.

You could leave the oil out completely, mind you – that’s how the watch came after all, but that’s not really a good answer to the eventual problems. Havoc would be reeked on the pivots eventually and the watch would just lose steam, and knowing that, I can’t forthrightly allow that to happen even if there’s a potential upside and you’d be staying true to the manufacturer’s designs.

I’d have to conclude that the ETA 7750 was picked to run the running seconds at 6 Daytona because of its power availability. An Asian could do the same for a bit, but not for a foreseeable future. And, ‘no oiling / means spoiling,’ basically. This is just one sample I’ve examined so up close, but usually it’s the same from one to another, like with the Asian 7750 – I always found them to be dirty un-oiled little brats. I’m just conjecturing here based on my limited expertise, I don’t know for sure – except about the no oiling means spoiling, that is definitely true.

Conclusions

One question to conclude on is – is this movement just for the Daytona – is that why it’s equal to an ETA 7750? Or, is this now going to be the new Asian 7750 basically? Thing is, my Omega BA doesn’t have this 7750 version, and it’s really the only one I’ve found. It’s hard to answer any of those questions. And how far-reaching is this movement anyway? I’m not sure – this piece came from a friend is all.

To say the least, this, as well as the newer 6497-2, are a sign of things to come and stay! If I could, I’d buy these in a 7750 and 7753 layout and just transplant the movement component into all Asian 7750 – that’s just how damned awesome they are!

Thanks for your time and consideration.
RG

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