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Miyota 8215 (and similar) clone movements compared

40857 Views 30 Replies 11 Participants Last post by Alpha-Getty, Jun 18, 2020

ej0rge

Discussion Starter · May 6, 2011

Arising from an attempt at identifying what beats within my MQJ sub, it was suggested that maybe we should have a thread dedicated to discovering the differences between the various miyota clones and how to tell them apart.

Going forward, some basic suggestions:

If pictures are taken with the rotor still attached, please take pictures with the rotor in two positions so as to show the whole back of the movement.

Close-up shots of the escapement are probably useful for identification as well.

Dial-side pictures if you dare remove the dial.

Please state what watch you found it in (if any), and if you believe you have clues as to it's make, state why you believe it may be what you think it is.

List the known features of the movement.

For starters, here is an "NN" stamped movement found inside an anonymous PAM homage. I believe the "NN" may be a dead giveaway for Nanning.

This movement hacks, hand-winds, and auto-winds in one direction only. standard 3 center hands, 12 hour movement. I have not had the dial off but close inspection reveals a date mechanism that is hidden by the dial.

Auto part Gear Wheel

Auto part Gear Rotor Circle Metal

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Reactions: 2

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ej0rge

Discussion Starter · #2 · May 6, 2011 (Edited)

Reposted from another thread, here are shots of the "B" stamped movement in my MQJ sub. The sesame-street fan in me wants to believe that B is for Beijing.

Note the similarity between the NN pallet cock and the B pallet cock - the same shape, but the "NN" version has a counter-sink for the screw.

Not to be confused with the "Shanghai B" which is a completely different movement.

This movement hacks, hand-winds, and auto-winds in only one direction. Has date feature.

The number under the balance is 227718810. I have no idea what this means.

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gigfy

· #3 · May 6, 2011

Here is a stock pic of a DG28. Cousins UK has dial side pics.

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ej0rge

Discussion Starter · #4 · May 6, 2011

The DG logo is easily identified, of course, and the finishing on this movement is similar to the NN stamped movement i posted. But note how the pallet cock on the DG version has a curved outline rather than the straight outline on the NN and "B" movements.

Pawl_Buster

· #5 · May 6, 2011

Here is the Miyota 8200(almost identical to the 8215 for this comparison...

The NN2813 and the DG2813(aside from the day feature on the Miyota) are fairly faithful clones of the Miyota. They share the same layout and with the exception of hacking; all the other features.
All three are autos onlt; that is, they only have a top plate that holds the works as well as the winding and mainspring systems. The do hand wind but are not and never were hand wind only models as they came from the factory.

There are teardowns of the Chinese ones in the resources section here. I have posted a teardown of the Miyota 8200 on other forums.

My personal opinion; which is based on actual experience with all three movements; is that the DG and NN are about the same in build quality, reliability and robustness while the Miyota lags a little behind. The biggest difference I've found is that the Miyota; while a good time keeper; isn't as accurate or precise as the two Chinese models.

Oh, yeh...ignore the obvious rust on the Miyota; it was a project that has since been completely restored.
Here is a shot of the restoration movement(on the right) and an older 8200 from about 15 years previous(according to the casebacks)...

Other than the rotors; the movements are almost identical in every detail.

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Chascomm

· #6 · May 6, 2011

Another difference between them is the shockproofing device on the balance cap-jewel. the DG and NN have the cloverleaf shape typical of most movements currently being made in the south of China, whereas the Beijing(?) has the older bowtie shape that persists in some of the northern manufacturers e.g. Sea-Gull and Liaoning. This difference can also be seen on some watches on the BWaF site. Just to confuse matters, I have seen at least one example of a Beijing watch with a movement of this type featuring the cloverleaf shockproofing. o|

ej0rge

Discussion Starter · #7 · May 6, 2011

Chascomm said:
Another difference between them is the shockproofing device on the balance cap-jewel. the DG and NN have the cloverleaf shape typical of most movements currently being made in the south of China, whereas the Beijing(?) has the older bowtie shape that persists in some of the northern manufacturers e.g. Sea-Gull and Liaoning. This difference can also be seen on some watches on the BWaF site. Just to confuse matters, I have seen at least one example of a Beijing watch with a movement of this type featuring the cloverleaf shockproofing. o|

I have heard some noise that the exact method of hacking varies between hackable versions as well but i don't know enough of the details. I remember that one of my miyota clones hacks by moving out a slender brass spring that gently presses against the surface of the balance wheel itself, but i don't currently recall which one.

Chascomm

· #8 · May 6, 2011

and now it is time to mess with everybody's head (heheh!)

Overe on the PMWF, Reto has an interesting watch in his collection:
Chinese Watches

It's the 'Eastown' on the right

Made by the "Shanghai Diamond Watch Factory" :think:

Chinese Watches Open

Now take a closer look...

It's nothing like a Standard or a Shanghai B, but very much like a Miyota.

These pictures date back to 2001 and likely the watch was made in the 1990s. The Shanghai Diamond Watch Factory was closed in 1999.

I have never seen another watch with this movement, but there it is; another indisputable Chinese pseudo-Miyota.

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ej0rge

Discussion Starter · #9 · May 6, 2011

Chascomm said:
It's nothing like a Standard or a Shanghai B, but very much like a Miyota.

These pictures date back to 2001 and likely the watch was made in the 1990s. The Shanghai Diamond Watch Factory was closed in 1999.

I have never seen another watch with this movement, but there it is; another indisputable Chinese pseudo-Miyota.

Yes, the resemblance to the 8200 is striking.

I wonder if the refinement of the clone movements starts by making a movement as close as possible to the real thing, and then gradually determining what improvements can be made to the manufacturing process based on the understanding of what really needs to be done and what the differences in capabilities are between the production lines.

saskwatch

· #10 · May 6, 2011

ej0rge said:
Reposted from another thread, here are shots of the "B" stamped movement in my MQJ sub. The sesame-street fan in me wants to believe that B is for Beijing.

Note the similarity between the NN pallet cock and the B pallet cock - the same shape, but the "NN" version has a counter-sink for the screw.

Not to be confused with the "Shanghai B" which is a completely different movement.

This movement hacks, hand-winds, and auto-winds in only one direction. Has date feature.

The number under the balance is 227718810. I have no idea what this means.

I don't know if this helps, but this is the movement inside my Beijing 8-1 commemorative for comparison. I haven't found any markings on it.

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ej0rge

Discussion Starter · #11 · May 6, 2011

saskwatch said:
I don't know if this helps, but this is the movement inside my Beijing 8-1 commemorative for comparison. I haven't found any markings on it.

Ahh, I think that does help.

If I'm working from the assumption that the NN pallet cock has a countersink that the B movement doesn't - or that it's simply a bigger countersink, and not just a different screw (I should take the screws out of both and have a look) - it would appear that your known Beijing has the same pallet cock as my "B" movement, and fairly similar finishing, near as i can tell.

Same bow-tie anti-shock, too.

Curious that the commemorative watch has no markings on the movement itself.

Chascomm

· #12 · May 7, 2011

ej0rge said:
I wonder if the refinement of the clone movements starts by making a movement as close as possible to the real thing, and then gradually determining what improvements can be made to the manufacturing process based on the understanding of what really needs to be done and what the differences in capabilities are between the production lines.

That makes good sense to me.

Chascomm

· #13 · May 7, 2011

ej0rge said:
Ahh, I think that does help.

If I'm working from the assumption that the NN pallet cock has a countersink that the B movement doesn't - or that it's simply a bigger countersink, and not just a different screw (I should take the screws out of both and have a look) - it would appear that your known Beijing has the same pallet cock as my "B" movement, and fairly similar finishing, near as i can tell.

Same bow-tie anti-shock, too.

Curious that the commemorative watch has no markings on the movement itself.

For further comparison, here is a useful close-up of Martin_B's hand-winding SB18 (borrowed from the BWaF thread)

This is the same movement as the one under discussion, only without the auto-winding parts.

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Chascomm

· #14 · May 11, 2011

From this related thread
https://www.watchuseek.com/f72/any-info-mingzhu-watch-movements-538122.html

Lairon's very useful photos of the 'Mingzhu 2836-2'; the 'unbranded' version of the DG28 with some Rolex-like embellishments.

The distinctive DG curved pallet-cock is clearly seen here.

Next question: Can somebody recognize in the above photo the hacking (stop second) device? From my own use of DG-powered watches, I am expecting it has train-hacking, rather than the more traditional balance-hacking, but it would be good to have it confirmed.

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Pawl_Buster

· #15 · May 11, 2011

Chascomm said:
From this related thread
https://www.watchuseek.com/f72/any-info-mingzhu-watch-movements-538122.html

Lairon's very useful photos of the 'Mingzhu 2836-2'; the 'unbranded' version of the DG28 with some Rolex-like embellishments.

The distinctive DG curved pallet-cock is clearly seen here.

Next question: Can somebody recognize in the above photo the hacking (stop second) device? From my own use of DG-powered watches, I am expecting it has train-hacking, rather than the more traditional balance-hacking, but it would be good to have it confirmed.

That picture doesn't really show what you want to see.

These do...

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Chascomm

· #16 · May 11, 2011

Thanks for those pictures :-! So it hacks on the 4th wheel.

Pawl_Buster

· #17 · May 11, 2011

Chascomm said:
Thanks for those pictures :-! So it hacks on the 4th wheel.

Yes; and that's why some times we see the second hand jump when releasing the hack.

Chascomm

· #18 · May 12, 2011

Pawl_Buster said:
Yes; and that's why some times we see the second hand jump when releasing the hack.

The only issue I've had withe DG28 hacking is the very occasional failure to restart. Then again, I've had the same thing happen with the balance-wheel hacking on the old Soviet Sportivnie. I guess sometimes you can catch it right at the point where the pallet teeth meet the escape-wheel such that friction hold them together. Probably means the watch is due for cleaning and lubrication.

The best hacking system that I've heard of is the one jointly developed by Citizen and HMT for the Indian airforce issued watch. It actually applies a slight impulse to the 4th wheel as it is released, ensuring that it never fails to start.

Meanwhile... getting back to Chinese pseudo-Miyotas; what other diagnostic differences can we find for distinguishing between unsigned movements?

ej0rge

Discussion Starter · #19 · May 12, 2011 (Edited)

Chascomm said:
Meanwhile... getting back to Chinese pseudo-Miyotas; what other diagnostic differences can we find for distinguishing between unsigned movements?

I thought i saw a difference in the cut of the winding wheels (spoked vs. a few holes vs. solid) but then noticed that the stock photo of the DG from the Cousins site has the spoked wheel that the Beijing, "B", and NN versions have.

How about the cut of the bridge next to the balance cock.

The genuine article and the DG have the bridge cut fully away, the Beijing has a parallel cut with a notch, and the NN and Mingzhu have a bridge that curves toward the balance cock.

lysanderxiii

· #20 · May 13, 2011

Chascomm said:
The only issue I've had withe DG28 hacking is the very occasional failure to restart. Then again, I've had the same thing happen with the balance-wheel hacking on the old Soviet Sportivnie. I guess sometimes you can catch it right at the point where the pallet teeth meet the escape-wheel such that friction hold them together. Probably means the watch is due for cleaning and lubrication.

The best hacking system that I've heard of is the one jointly developed by Citizen and HMT for the Indian airforce issued watch. It actually applies a slight impulse to the 4th wheel as it is released, ensuring that it never fails to start.

Meanwhile... getting back to Chinese pseudo-Miyotas; what other diagnostic differences can we find for distinguishing between unsigned movements?

Failure to restart is almost always due to the movement being out of beat. The neutral point of the ballance should be with the impulse jewel (trying) to hold the pallet centered. The tension on the escape wheel will, however, snap the pallet one way or another against the banking pins kicking the balance into motion.

If the movement is badly out of beat, the neutral point of the balance will allow the impulse jewel to sit in the pallet fork while it is against a banking pin, motionless.

EDIT: In fact, if you do not have a timing machine, you can use this to put your watch "in-beat".

1) you get the balance to stop where it wishes to withthe hack "off".
2) move the balance spring stud until the movement kicks off.
3) repeat until you cannot get the balance to stop with the hack "off"

You can get the beat in to within about 2 ms this way, depending on the lift angle.

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