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Discussion Starter · #1 ·
Hey guys,

I tried to find something that explain drawing, but not being succesfull, i turn myself to you guys..
i might need a little help about reading the information given on the technical drawing of a movement, for being able to design a watch dial, case and movement ring!

Let's take the Miyota 8219 movement as exemple.

http://miyotamovement.com/pdf/draw_8219.pdf

Let's start with what i understand..

On page 1,
- That's god damn lots of informations!
- Only the 2nd drawing i can understand thing.. Like the hands heigth and width, movement height and width.
- What the section CS1.CS2, DS1.DS2 & view A-A show us?

On page 2,
- I do understand its the drawing showing where hand goes, date hole & dial feet goes. If i understand right, i can make a dial with the size i want, as long i keep the right measure for hand, dial feet and date hole?
- The 2nd drawing, its showing the thickness of dial? with measure for hands holes? What confuse me, is the unit.. What does 400±40 supposed to mean? or O2000±40. I do know it 1/1000 scale, which would mean a 2MM hole, but ±?

On page 3,
- I've read we make case according to the stem length? Or we can just get a longer stem which fit this movement?
- A-A section, is this the section that stay out of the movement? But the measure say 20mm, from top to lower than A-A section.. So does it mean, the stem is 20mm long in total? Where does the stem stop inside the movement?

On page 4,
- I guess its the movement ring..
- i dont understand the whole thing in this page..
- Oh ya, its made of plastic..


With all the information i've in this drawing, i should be able to make all i need? Dial, case, ring, etc.? What i did understand, it's i can make a watch case with the size i want, i only need to find or make the proper movement ring to hold it in place?

Thanks alots guys for the help! Sorry if this has already been asked or discussed..








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Hi Machfive.


I'll have a go at answering some questions and see how we go.

I would think the easy bit is that you have the movement and you should also buy the movement casing holder as it is pointless trying to make one yourself IMO.

I haven't worked with the measurement system and tolerances like that but it says they are working on microns i.e. one thousandths of a millimetre (or one millionth of a metre if you like).
Your 400+/-40 means 400 microns (0.4mm) and the dimension can be bigger or smaller by 0.04mm which is called the manufacturing tolerance.

Starting from the outside you have a casing holder of 29.230mm.
So you can have a chunk of case metal with a hole slightly bigger than that. How much? Someone here can probably tell you but I'd suggest probably 1/10mm on each side so a diameter of 29230 + 0.100 + 0.100 so 29430.

Next you'll need to work on the depth of the movement cavity.
On the side elevation in the first drawing it's not really clear to me where the casing holder would support the movement but it looks like it holds the movement under the dial where it says Movement Holder Plastic.

I'd also suggest that you understand that if you are wanting to use a standard Setting Stem you will need to make the case no thicker (radially) than a standard case other wise you will not be able to seat it.
The portion of the setting stem designated S0.9,P=225mm is the thread the crown will screw on to. Looks like 0.9mm diameter with a thread pitch of 0.225mm. This is sometimes made longer and can be cut to suit.

Having said all this, I think by far the easiest thing to do is to buy the movement, casing holder and stem and start building your case and dial from there.
It will make much more sense when you have it in your hand.

I wouldn't be too put off with the micron tolerances though because watchmakers many times make items on a lathe for instance with a vernier and that is nowhere near those tolerances.
These fine tolerances are there for manufacturing so that all the parts will interchange.

If you are making a one off then a good lathe or CNC and some fine abrasive paper should be more than enough.

Only problem is that one must be reasonably proficient with the machinery and I'm a bit worried if you have to ask about +/- tolerances.


Good luck with your project.
 

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Discussion Starter · #3 ·
Wow, thanks 1afc for taking from your time to reply! Sorry if my answer is a bit of stupid, i'm still learning alot for watchmaking and i think its by asking questions and doing error we learn more..
Easy way, would be to make the dial and only find already made case, band and put them together, but i really want to go deeper on the subject.


You're right, i dont plan to use lathe or CNC by myself. For now, the fun for me is only to draw dial & case prototype in illustrator. But actually, i want to be more accurate in my drawing, which who might lead to a real prototype for myself and my own enthusiast.

Thank you for explaining the microns! As you said, i'm pretty sure this shouldn't bother me for what i plan to do.

I'm getting confused about the stem, i get it the diameter is 0.9mm with 0.225mm pitch, but i'm more concerned about the total length of the stem. I cant figure which section of the stem get inside the movement and which stay out of it..

Also, the original holder, for me would be a bit small.. Since i'm looking for a 40-42mm case. Or i can make the hole of the casing about 29.43mm with larger thick, but i would have to change for a longer stem?

I'll do what you said, get the movement, stem and holder. Thanks for that advice! Just getting hard time to get the movement with holder! ahah but still looking around.
 

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Hi Machfive

Now that you have explained a bit more I have a few more suggestions.

The first is that you should buy the cheapest watch with the movement you want to use. That will start to explain many things and you need the movement anyway.

It will also help you explain to the machinist what you are talking about.
It will also make you understand the need for other things like the design of the case closure method and the possible need for a stem bushing to support the stem going through the case.

I would use the supplied case holder and make up a plastic spacer to take it to the diameter of your case internal dimensions. If you wanted, you could then just glue the two pieces together.

I wouldn't make the case internal diameter smaller as it will then have a lot more metal and will be heavy.

The part of the stem without the screw thread is the part that goes into the movement. The crown is screwed onto the threaded bit.

You will probably find that the stem in the watch you buy, if you go that way, will be shorter than the one in the diagram. They manufacture the stems longer so they can be cut down to the required length.

I'd be searching youtube to find out how watches are put together.

With regard to the dial, that is interesting as well.

I'm currently researching dial printing and that is enough of a dark art by itself.

This is a long path so take lots of provisions with you.
 
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Discussion Starter · #5 ·
Hi Machfive

Now that you have explained a bit more I have a few more suggestions.

The first is that you should buy the cheapest watch with the movement you want to use. That will start to explain many things and you need the movement anyway.

It will also help you explain to the machinist what you are talking about.
It will also make you understand the need for other things like the design of the case closure method and the possible need for a stem bushing to support the stem going through the case.

I would use the supplied case holder and make up a plastic spacer to take it to the diameter of your case internal dimensions. If you wanted, you could then just glue the two pieces together.

I wouldn't make the case internal diameter smaller as it will then have a lot more metal and will be heavy.

The part of the stem without the screw thread is the part that goes into the movement. The crown is screwed onto the threaded bit.

You will probably find that the stem in the watch you buy, if you go that way, will be shorter than the one in the diagram. They manufacture the stems longer so they can be cut down to the required length.

I'd be searching youtube to find out how watches are put together.

With regard to the dial, that is interesting as well.

I'm currently researching dial printing and that is enough of a dark art by itself.

This is a long path so take lots of provisions with you.
I'll for sure, i got few old citizen laying around, i just received my tool, so i'll be able the open them and play around. But they're all quartz.

Also started to read Pratical watch repairing from Donald de Carle.

Again thanks you for your time and reply.

Going to also order a cheap automatic movement to play around with it and the movement i want to base my watch on!

Sent from my LG-D852 using Tapatalk
 
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