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Disassembly reassembly of automatic + date movement


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Hello,

today I successfully disassembled and reassembled my second ST36 for the third time with no breakage or lost parts. So since I still have half a day off I decided I’ll try something new and more ambitious (if uglier and cheaper). 
I have two brand new movements which are automatic and with date. A DG2813 and an NH35A. I want to use the NH35A to make a watch so right now I figured I’ll practice with the DG2813 which only cost me $17 shipped. 
I have found a video from the Watchsmith on how to assemble it and I wanted your opinion on order of disassembly. 
For reference here are my notes on how I disassemble the ST36 (attached file, I have detailed notes on each step but I won’t bore you with them). The movement is bare so steps 1 and 2 are irrelevant. 
I think I will add 2.5 remove the rotor. 
Now comes my question:

where would you insert the steps:

remove automatic works (appart from the rotor)

remove the calendar 

 

thank you for your help. 

image.jpg

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Well I started with the rotor, then I couldn’t find how to let down the power so I removed the balance then found the click and let down the power. 
After that I took apart most of the watchmaker side with the exception of the hour wheel which was still held by the cannon pinion and the hour wheel bridge which I put back when I realized the above. 
I then went to the dial side and removed the cover plate. There were a few flat part which I had no idea what they were or where they should go as they got stuck to the plate by lubrication. Luckily I found an assembly video of that movement by the watch smith and he explained that those parts are part of the quick date setting system. 
So I put them back in place and took a picture before continuing the disassembly 

One thing I keep hearing in video or seeing in forums is that Chinese movements are often not lubricated. WellI can tell you the one I have is drenched in oil. Everything is stuck by capillary action on the dial side and I see pools of oil under each wheel. 

Quite a bit of lint stuck to the oil too

Just realized there were 3 screws, 2 holding the yoke maintaining plate and 1 holding the setting lever jumper.  I hope they are the same because I mixed them up and I can’t tell them apart. 
 

Done with the disassembly and done for the day. For the reassembly I have a video to follow which is great because the dial side is quite complicated and I couldn’t take good pictures of the components position as several got stuck on the plate by lubricants as I lifted it so I never saw where they were supposed to be. 

IMG_9992.jpeg

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Posted (edited)
14 hours ago, Terrinecold said:

DG2813

The problem with a watch like this is where is the technical information? I wasn't even sure that was even based on anything it looks from the link I have below it is based on a real watch well loosely based so maybe there's technical?

https://calibercorner.com/pts-caliber-dg-2813/

There guess the watch company has a tiny bit of technical they acknowledge they made the watch but not seeing any service information?

https://miyotamovement.com/product/8215/

I did finally find a service sheet for the watch but as it said in the first link it's not an exact clone so that will be some variations. The problem with the Chinese watches they do not supply any technical information spare parts or anything at all other than a cheap watch Which is fine until you go to service the thing and then they'll be problems. On the other hand there clone of the 6497/6498 pocketwatch is almost identical and that means that there is a Swiss tech sheet available which is very very close unlike here where there'll be some differences

14 hours ago, Terrinecold said:

NH35A.

Now this is a much better choice for watch as they have a website. I'm attaching the technical information for your watch from the website at least they have a really decent service guide versus the Chinese.

https://www.timemodule.com/

 

 

 

 

 

 

8691_276584548-Spare-parts-reference-for-the-Miyota-8205-8215-movement.pdf NH35_PL.pdf NH35_SS.pdf NH35_TG.pdf

Edited by JohnR725
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Yesterday evening I worked on the reassembly using this video as a guide:

This was an exercise in frustration.

The first problem I had was that I think Alex is taking a shortcut in the video editing. He turns the movement over to install the keyless works after setting the barrel. However that barrel is held by nothing so I couldn’t find a way to perform the installation in that order. Instead I installed the gear train and main bridge before the keyless works. 
Second problem was there. The bridge on this movement (and I understand it is the same on the 8215 it is based on) is extremely finicky as it covers 5 pivots and has a spring in the center. 
I finally installed the bridge and realized I forgot to install the click. This seems to also be missing from the video 

 

At this point I turned movement around. And I installed the first part of the keyless works.  This part should skill of Alex, who had no problems with it.  On my side, I kept having either the yolk or the setting lover jump out of the way whenever I was trying to install the plate which is supposed to secure them.
I finally managed and went to the next step.


 I turned the movement around again. Remove the bridge, installed the click and took an over half an hour putting the bridge back on.

I sincerely expected that I was done with the hard and frustrating part, but it wasn’t the case. Back on the side it was time for the calendar system, and the motion works.  Mostly that was fine, except for the last part of the calendar setting  system.  I had put the date jumper in placed as well as it spring, and when I was trying to set the jumper in the correct place in the date ring, true to its name, the thing and it’s spring jumped all the way across my desk.

 I found the jumper, but never found the spring. 
I will look for it more this evening, but I doubt I will find it and this movement will pretty much end up without a working date jumper. 
The worst part was, I thought I was done. I was feeling happy about myself and being there goes the jumper in the spring.

This will be a lesson. I guess this is why practice is necessary.

 

 

 

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Posted (edited)
1 hour ago, Terrinecold said:

over half an hour putting the bridge back on.

Don't worry, you're doing well. This is an absolutely normal amount of time for the first few movements you put together. You'll get much quicker with practice. 

Small trick: tap the movement holder lightly with your tweezers or something. That help make the pivots fall into place.

Game changer: stereo microscope (will let you see clearly where pivots are and when they go in).

 

1 hour ago, Terrinecold said:

but never found the spring

As frustrating as it is for you now, don't worry (again). This has happened to all of us on our first couple of movements (and sometimes still). A few tricks:

- always use two tools (one to manipulate the spring = tweezers; and one to stop it from flying, such as a stick of pegwood, the wide+flat side of a component probe, or a jewel picker-upper)

- work "through" a thin sheet of transparency plastic 

- use a bit of Rodico to secure the parts (I'm not a fan of this approach, but others seems to like it)

Edited by Knebo
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@Knebo thank you for your reply and encouragements.

Indeed that corresponds to things I had figured out.

  • The bridge:  I think that bridge is especially frustrating because of a small spring underneath it which means it doesn't fall into place you have to lightly push on the bridge for it to be at the correct height and if you stop that pressure some pivots come out.  Because I don't yet have the correct dexterity when I move the wheels to make the pivots go into their hole I tended to move the bridge too.  One trick I used was to position the bridge where it should be and screw the screws a couple of turns so that there was still plenty of up and down play for the bridge but not too much side to side.  I do have a stereo microscope and indeed without it and without seeing the pivots through the jewels there is no way I could have done it.
  • The lost spring: again you are completely right and I have been doing that for the most part when I manipulate springs (and in particular when trying to set the keyless work, I just didn't have enough hands to hold the pegwood in one hand, the tweezers with the retaining plate in the other, the tweezers with the screw in the third hand and the screwdriver in the fourth.  The spring I lost though was already in position and somehow (it was 11h30pm that might have something to do with it) I forgot that when I was moving the setting lever there was a chance for the spring to pop out of its recess.

 

 

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4 hours ago, Terrinecold said:

I will look for it more this evening, but I doubt I will find it and this movement will pretty much end up without a working date jumper. 
The worst part was, I thought I was done. I was feeling happy about myself and being there goes the jumper in the spring.

This is the absolute worst feeling. I've been working on watches over 2 years now, and serviced dozens of movements. You do get better at it, and lose fewer parts.

I don't know if it helps, but just last week while installing a shock spring on a friend's late father's Omega, the spring took flight.

It took almost an hour of searching with a very strong magnet attached to a Mason jar lid to find it, but I found it.

IMG_20240520_201030.thumb.jpg.c2efad98fedd503d124831b7b7da49e1.jpg

The VERY NEXT DAY while oiling the cap jewel for the same movement, I pinged the jewel to dimensions unknown. I used a UV flashlight to find it. Some days it's just not your day 🙂

 

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By the way this is my watchmaking (more like watchbreaking) setup. I still haven’t found the lost spring. The date jumper “jumped” from the mat where the movement was to the top of one of the citizen boxes on the right storage drawers. I don’t know if the spring went in the same direction or how far it did. 

IMG_9994.jpeg

 

 

8 minutes ago, ManSkirtBrew said:

This is the absolute worst feeling. I've been working on watches over 2 years now, and serviced dozens of movements. You do get better at it, and lose fewer parts.

I don't know if it helps, but just last week while installing a shock spring on a friend's late father's Omega, the spring took flight.

It took almost an hour of searching with a very strong magnet attached to a Mason jar lid to find it, but I found it.

IMG_20240520_201030.thumb.jpg.c2efad98fedd503d124831b7b7da49e1.jpg

The VERY NEXT DAY while oiling the cap jewel for the same movement, I pinged the jewel to dimensions unknown. I used a UV flashlight to find it. Some days it's just not your day 🙂

 

@ManSkirtBrew I feel you. 
I have tried looking with magnets I have attached a strip of magnetic tape to a piece of foam board which I use a bit like a broom. It never found anything though the magnets are pretty weak though and it is likely the reason

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5 hours ago, Terrinecold said:

This will be a lesson. I guess this is why practice is necessary.

I will often relate learning watch repair is similar to learning to become a doctor. It requires studying may be reading a book definitely reading tech sheets if you can find them but studying understanding. Then practicing continuous practicing forever practicing. Everybody preparing a watch no matter what the level is still practicing exactly the same as a doctor. There are no absolute experts everybody has room to learn.

5 hours ago, Terrinecold said:

spring

Typically for Springs a magnet will work really well. Then by magnet I don't mean a little magnet something much larger at work we have something that's mounted on a handful with a rather powerful magnets that we can sweep across the floor and sometimes across our bodies looking for hoping to find which for the most part we do.

5 hours ago, Terrinecold said:

Alex is taking a shortcut in the video editing

Unfortunately there's a lot of problems with YouTube watch repair videos. For instance the video that you have says servicing? Did he actually service the watch in other words were repairs made or is this really a how to clean the watch video?

Then even just for servicing no problems you just disassemble clean the watch put it back together how long does it take can you do it in 15 minutes? How long did the video last versus how long did it take you to service the watch? They skip steps lots of steps so many of the watch repair videos are really entertaining videos that don't cover everything and usually definitely do not cover repairs. At least not a lot of them.

 

4 hours ago, Knebo said:

Game changer: stereo microscope (will let you see clearly where pivots are and when they go in).

4 hours ago, Knebo said:

Small trick: tap the movement holder lightly with your tweezers or something. That help make the pivots fall into place.

This presents an interesting problem? Watches like this were assembled with automated machinery gears all drop in the place the plates drops on top no human hand touch this watch. But a lot of watches specially vintage stuff tapping Is wishful thinking if you think the pivots will go into place. This brings up a problem with stereo microscopes you're looking straight down. In the dark ages of watch repair when I learned we didn't use microscopes and we were instructed to sit in such a way that you're basically looking into the watch's you can see in the pivots you can see what's going on. Often times I've seen when people are looking straight down even with their super high-power microscope they just really aren't getting a clear picture of what they're doing. It be better if your microscope could be angled at an angle so you can see things a little better as opposed to looking straight down. But I'm sure the entire group embraces their microscope so this would go against the group so carry on with your microscope.

 

 

 

 

 

 

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1 hour ago, JohnR725 said:

But a lot of watches specially vintage stuff tapping Is wishful thinking if you think the pivots will go into place

It doesn't magically make them all fall into place, but it has helped me a few times. 

 

1 hour ago, JohnR725 said:

This brings up a problem with stereo microscopes you're looking straight down

Actually not. You can angle them. Well, depends on the model, but I believe most people on the forum use similar types that can definitely be angled. 

.. theoretically even to the point that you look sideways into the movement, but practically not really (because then the eyepieces are in a very weird position and hard to look into. 

But the magnification, lighting (with LED ring) and overall (stereo) clarity of vision really help a lot. E.g. you can see a pivot through the jewel when it touches the jewel but hasn't gone into the hole (when looking straight down) - then you can nudge the wheel and see the pivot move towards the hole. Just an example. 

I worked without a stereo microscope until March this year, so I know it's possible without. But having one now, I wouldn't want to go back. 

Kudos to you for sticking up for the traditional way and persevering. You got the skills and experience.. 

2 hours ago, Terrinecold said:

By the way this is my watchmaking (more like watchbreaking) setup

Looks good! 

By the way, another tip that is rarely talked about:

Invest a few minutes in dressing your tweezers and screwdrivers. That'll help a lot in not slipping and not loosing parts. 

As for screwdrivers, it's really worth adjusting them to the screws of the particular movement. E.g. I was working on a vintage Omega where the screw slots were very thin/narrow. It was imperative to sharpen the tips of the screwdrivers to get in properly. Afterwards I worked on a Rolex where the slots were rather wide. Leaving the screwdriver tip as thin and sharp as before would have resulted in slippage, bad grip and damaging the screw slots. So had to file down the screwdriver again. It can feel annoying to do this when you're eager to get started on the watch, but you'll thank yourself if you take a few minutes beforehand. It'll save you a lot of pain. 

Tweezers the same. If they aren't dressed properly, everything becomes more difficult and you'll loose parts. 

This video is helpful: 

 

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@ManSkirtBrew yesterday was my first day practicing cleaning and oiling. Of course I had to deal with the balance jewels the first one went fine but in case of the second one the incabloc spring came of its slot instead of hinging upward and when I tried to put it back I held it a bit to firmly and it pinged away. 
I searched and couldn’t find it. Then this morning when cleaning my workbench to prepare for today’s practice I found it. It was just off the edge of my mat and the tiny thickness of the mat had hidden it from my view when searching. 
 

Any tips on how to put the back end of those in the slot of the shock system (I call back the part that hinges not sure if that is correct)

IMG_0010.jpeg

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Posted (edited)
32 minutes ago, Terrinecold said:

but in case of the second one the incabloc spring came of its slot instead of hinging upward and when I tried to put it back I held it a bit to firmly and it pinged away. 

Oh no, I cursed you!

So I found that no matter how much I demagnetized my tweezers, the spring, and the movement (if you try this, make sure the spring is inside a container or it will fly away), it still wanted to stick to my fine steel tweezers.

So I stuck some Rodico on the end of a pegwood stick (my favorite tool) and stuck the prongs of the spring in that. I then used my brass tweezers to gently nudge the spring's hinge into the slot in the chaton.

I had to do it at least twice on that Omega, but the Rodico-on-a-stick trick really saved the day. It prevents you from pinging it away and really makes it easier to navigate the spring into its slot.

Edited by ManSkirtBrew
Pithwood != pegwood
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Nice trick I’ll try that. 
 

I don’t think you cursed me I think at this point I am so clumsy that everything bad which can happen is bound to. 
The microscope helps a lot but dexterity with tweezers is not there. 

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Also what I've found is when doing this sort of fiddly work with your tweezers, less squeezing and more nudging is the way. I feel like I can be a lot more precise with a gentle push than trying to use my squeezy muscles while moving parts at the same time.

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