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.

 

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

 

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.

 

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.

 

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.

 

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.

 

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.

 

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...

 

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.

 

Sorry for posting on such an old thread, but I have a question regarding 8215.

How do you remove the stem, so as to take the movement out of a watch case? Do you just pull on it a bit hard?

 

Sorry for posting on such an old thread, but I have a question regarding 8215.

How do you remove the stem, so as to take the movement out of a watch case? Do you just pull on it a bit hard?

There is a small button on the movement, near to where the stem enters. Press the button and gently pull out the stem.

 

Sorry for necro posting but I am looking to buy a 8215 movement, will the hands from my 2813 fit this movement? Or do I need to broach wider diameter holes for the hands?


Sent from my Mi A1 using Tapatalk

 

Sorry for necro posting but I am looking to buy a 8215 movement, will the hands from my 2813 fit this movement? Or do I need to broach wider diameter holes for the hands?

Based on this thread:
https://www.watchuseek.com/f318/com...n-selected-11-5-movements-interchangeability-torsten-v5-july-2013-a-467694.html
...it looks like they are pretty close, but the minute hand is slightly wider on the 2813

 

I am very surprised n-one has mentioned the Seagull ST16 or TY2806 movement in this discussion. I have only had my hands on one of these, but it ran very well, and after just one stab of regulation, performed so accurately I was loathe to put it in the watch I was building for someone.

 

Unfortunately, over the years, the ST16 has varied in quality so unless we are talking about one of the AAA movements from Tianjin there is no meaningful comparison.
I would put the best ST16s up against the NN and DC movements all day long.

And we mustn't forget this one...

 

A long time ago on a forum now dead, the owner of the site bought one of these Zodiacs and had it disassembled. The jewel count was actually 21 as you would expect.
Other than the obvious CL*** stamp and a bead blasting of the plates, nothing else showed up as being different than any other ST16 from Tianjin.
This was an obvious attempt to distract anyone from thinking this was a Sea-Gull movement.