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 [Bricolage-DIY] fabrication Masion d'un cadran de montre

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Dynamo
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Dynamo

Nombre de messages : 7028
Localisation : Paris
Date d'inscription : 05/05/2005

[Bricolage-DIY] fabrication Masion d'un cadran de montre Empty
MessageSujet: [Bricolage-DIY] fabrication Masion d'un cadran de montre   [Bricolage-DIY] fabrication Masion d'un cadran de montre EmptyDim 21 Aoû - 7:49

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Robert L. Frazier a écrit:

Dial Making HOWTO
HOWTO make watch dials.

Section 1 -- Making the dial blank.
Section 2 -- Making the screen stencil
Robert L. Frazier a écrit:

Section 1 -- Making the dial blank.


Tools used

- Metal for the dial blank.
- Drill, power and hand, fine.
- Hard, thin, clear plastic, for dial stencil.
- Scribe
- Ginder
- Toothpicks
- Soft solder (40%tin/60%lead)
- Copper wire (about .7-.8mm diameter).
- Tweezers, medium, e.g., Nr 2.
- Solder flux.
- Soldering plate.
- Torch.
- Helping hands.
- Paint stripper.
- Fine snippers.
- Fine file
- Broaches.
- Loupes.
- Pin.
- Pin vise.

Making the disk.

You need a round disk of the correct diameter and the correct thickness. For thickness, about .4---.45mm seems good. The diameter depends on the watch case being used. The first object is to have a disk with a hole in the middle for the center pinion. For this you can either use a lathe, a saw, or another dial that is bigger than you need. Since I don't know about lathes (I wish I did), I'll just mention the other two methods.

If you are using a saw, e.g., make a hole in your brass (or whatever) of about 1.5mm. Then cut a disk a bit bigger than you need with that hole at the center.

If you use another dial, strip the paint and cut off the dial feet. Then file or grind the place where the dial feet were until flat. In Picture 1, you can see where the new dial feet are, as well as where the old ones were.

Once you have a disk that is a bit bigger than you need, you need to grind it to the exact size required. I use a bench grinder for the coarse work, and a mini-tool grinder for finishing it. The trick is to keep it round. For this, I use a variation on turning (where the cutting tool stays stationary and the object being cut turns). I put the disk on a toothpick, and carefully hold it next to the grinder (be extremely careful, and have a clear work area). This way the grinder grinds away, and the disk spins, keeping it round. (Picture 2.) You might have to change toothpicks, as the disk will cut into them. Don't try using something harder, as it will cut into the disk and enlarge the hole. (Guess how I know this.)

You now have a disk with a center hole of the correct diameter. You now need to add the dial feet, and, possibly, the hole for the sub-seconds pinion. For this, a dial stencil is useful.

Dial stencil

When the movement is apart, I take the movement plate and make a stencil in plastic of the location of the center, 3, the dial feet, and the sub-seconds pinion. You could do this with the movement together, I believe. The idea is to make pin marks where appropriate then to cut small holes in the plastic. It is important to make note of the orientation, otherwise you will put things on the dial in a mirror image. Picture 3 shows a stencil for a Longines 23M.

Remember we are talking about small items and tiny distances. Close does not count. You have to use an eye glass when doing this, or at least I do. Also remember that using an eye glass distorts perspective. Things may look straight from the angle you are looking, but not be.

Marking the dial

Take the stencil and put it on the movement side of the disk. Make sure everthing is lined up. I put a small indentation on the side of the disk in one place to mark 3. So, with the center hole and 3 marked on both the stencil and disk, you should be able to line things up exactly. Also, be careful here about orientation, you don't want the dial feet and sub-seconds in a mirror image of where they should be. Now using a scribe or pin, mark the various places on the dial.

Adding the sub seconds hole

If you are using sub seconds, drill a hole in the appropriate place. I go for about 1mm in diameter. Smaller would probably be better. It depends on the pinion of your movement. Finally, file or sand or grind the edges of the hole so they are smooth.

Adding the dial feet

Take a fine drill (say .9mm) and drill into the dial where the dial feet are to go. (Picture 4.) You only want to drill a little, about half way (.25mm). You can use the power drill, if you are brave, but a hand drill might be safer (I use a pin vise).

Now take a length of copper wire and file the end a bit so that it angles in, but still has a flatish end. Put a bit of flux in the hole. (Picture 5.) Get the filed end of the wire to stand straight up in the hole. I use a broken helping hands to position it. Put a bit of solder (1mm) next to the copper wire. (Picture 6.) Tweezers come in handy here. Now take the torch, light it, and heat that area, being very careful not to heat the other dial foot, if it has already been done. Move the flame in and out just until the solder flows.

After the solder cools, the copper wire should be firmly attached. Cut it about 1.2mm from the dial. Then file it to the appropriate length. I use a failed dial to hold it when I am filing. I put the foot

Finished dial

You should now have a dial blank, with the dial feet, etc., in the right place. I messed up my first attempts. You may too.
You may have to file away a bit of the solder, if it sticks up too high. Also, you may have to broach the center and sub seconds holes. Better to make them too small and have to enlarge them, than the other way around.
This may seem involved. It is in a way. There just aren't any decent shortcuts. Dial collants (two sided tape), super glue and epoxy just don't work for me. However, it doesn't really take all that long.

Pictures for Part 1

Note: These pictures are a reconstruction. When I am doing it for real, I have to concentrate.

Picture 1. Here is a completed dial. You can see where the old feet used to be
[Bricolage-DIY] fabrication Masion d'un cadran de montre Dialcomplete5zg

Picture 2. Grinding the disk to the right diameter. [Bricolage-DIY] fabrication Masion d'un cadran de montre Grinding5dc

Picture 3. A dial stencil.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Dialstencil2nh

Picture 4. Hand drilling the indentation for the dial foot.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Handdrilling8uy

Picture 5. Putting the flux in and around the indentation.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Flux4cc

Picture 6. Everything ready to go. The wire is in the hole, and the solder is against the wire.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Solderready9ym

Picture 7. The dial foot being held by a failed dial and ready to be filed.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Filing2gb
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Dynamo
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Dynamo

Nombre de messages : 7028
Localisation : Paris
Date d'inscription : 05/05/2005

[Bricolage-DIY] fabrication Masion d'un cadran de montre Empty
MessageSujet: Re: [Bricolage-DIY] fabrication Masion d'un cadran de montre   [Bricolage-DIY] fabrication Masion d'un cadran de montre EmptyDim 21 Aoû - 7:49

Robert L. Frazier a écrit:

Section 2 -- Making the screen stencil

Tools used

- OHP transparences.
- Computer and printer.
- Drawing program (vector graphics).
- Fine screen (for main printing).
- Coarse screen (for printing luminous material).
- Diazo light sensitive emulsion.
- Screen filler.
- Masking tape.
- Straight edge (e.g., metal ruler).
- Light socket.
- Foil pie pan.
- Nr 1 photo floodlight.
- Timer (e.g., watch with bezel).

Suppliers

For screen printing material, I have used a local printer, Colenso, and Selectasine Serigraphics. I am more inclined to use the local printer now, as they have been a big help.
The photo floodlight bulb can be got at most photo stores

Preparing the dial images.

The higher the resolution of the printer the better. I'm now using an Epson R300 at 2800 x 1440 DPI. (I suspect that there is a formula saying what the resolution should be for a certain screen size.) My experience is that it is better to use a program that does vector graphics than it is to use one that does bitmap graphics. This is mostly because it is easier to scale vector graphics. So make your dial image, and print it on the OHP transparency film.

Below are my dial graphics files, which you are free to use as outlined in the GNU Free Documentation License.

Each picture is a link to the encapsulated postscript file (EPS) for that dial image. The EPS files are in scalable vector graphics format. The fonts are embedded, you so may have some luck scaling them to the size you want. It is important to realize, however, that scaling one with a subseconds dial will place the subseconds in the wrong place. You have to remove the subseconds dial and make it anew at the right place with the dimensions you want.

6497 -- 35.5mm dial, with sub seconds at 9 o'clock, with the center of the seconds hole 1 cm from the center of the dial.
[Bricolage-DIY] fabrication Masion d'un cadran de montre 6497

6497_lume -- Luminous material pattern for above dial.
[Bricolage-DIY] fabrication Masion d'un cadran de montre 6497_lume

expl -- 28.5mm dial.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Expl

expl_lume -- Luminous material pattern for above dial.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Expl_lume

Oblique -- 29.5mm dial.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Oblique

Oblique_ss_60 -- 29.5mm dial, with subseconds dial 6mm from center.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Oblique_ss_60

Oblique_ss_65 -- 29.5mm dial, with subseconds dial 6.5mm from center.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Oblique_ss_65

Oblique_lume -- Luminous material pattern for the Oblique 29.5mm dials.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Oblique_lume

Oblique_2475 -- 24.75 dial.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Oblique_2475

Oblique_2475_lume -- Luminous material pattern for the above dial.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Oblique_2475_lume

plain_2475 -- 24.75 dial.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Plain_2475

plain_2475_lume -- Luminous material pattern for the above dial.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Plain_2475_lume

Coating the screen

There are lots of instuctions out there on coating the screen, so I'm just going to tell you quickly how I do it, and give some hints. Here is a link to some very good instructions. Speedball PDF Screen Printing Instructions

You should clean the screen and let it dry before coating it. In order for the emulsion to adhere properly, the screen has to be grease free.
You can only use the center of the screen. Trying to use too close to the edge becomes tricky, and not worth it. The screens I use have aluminum frames. The screen+frame size is about 50cmx42cm. The screen area is 45cm x 36cm. The usable area is 35cm x 26cm. In this area I have been putting about 8 dial images. In the future, I will put fewer.

When coating the screen, I put wide masking tape down each side of the screen (excluding the frame). This gives me the working area. It also helps in coating the screen. The light sensitive emulsion has to be put on thinly and evenly. I use the masking tape to regulate the thickness of the coating. I put a thick bead of emulsion along one end of the screen. Then I take the ruler and run it down the screen, with the screen horizontal, and the edges of the ruler on the masking tape at the sides, pulling the bead of emulsion toward me. This gives me a fairly even coating of about .1mm. I do it on the outside of the screen first, then the inside of the screen. Coating the screen has to be done in yellow light conditions.

The emulsion I use is a two part emulsion. After it is mixed, it should not be exposed to light. Indeed, after being mixed, the container should only be opened in yellow light conditions. When mixed, it has a shortish shelf life, which can be greatly extended by keeping it in the refrigerator. (An understanding household comes in handy here.) I've probably made about 15 screens in the last few months, and the emulsion has kept perfectly well in the refrigerator.

For fine printing I have worked up from 72 to 120 to 180 threads per cm. I might even try 200 threads per cm in the future. (It is important to keep in mind the measuring system. In the US, people talk about threads per in.) For printing luminous material, you have to use more in the region of 44 threads per cm, since the luminous material is much larger than pigment in paint. (I've been searching for v. fine luminous material, but haven't found it yet.)

After the screen is coated, you have to let it dry in the dark. I would give it overnight, but 3 hours is the recommended minimum time. You should let it dry with the outside of the screen down, and the well of the screen up. So that the wet screen does not touch anthing, the corners have to be raised, e.g., with bits of wood or coins.

Burning the images

After the screen is coated and dried, it is time to expose the dial images on the screen. (You are making it into a stencil.) It is easiest to use the photo floodlight. You make a support for the screen, cover the support with black cloth (to keep light from reflecting), put the screen over the support with the screen outside on the top (the well on the bottom), put the dial images on the screen (you have to place them in a mirror image, so that it is the right orientation from the inside of the screen), put a piece of glass on the top of that to hold the images firmly against the screen, and turn on the light.

The screen printing instructions I linked to above gives more information about this. For the size of screen I use, I have the light 1 ft from the screen. I expose the fine screen for 8.5 minutes, and the coarse screen for 11.5 minutes.

After the screen is exposed, you have to wash it out. The pressure of the water should wash out the areas that haven't been exposed to light: the dial patterns. This gives you the dial stencil. It sometimes takes a little while for the screen to start opening up (the unexposed bits to wash out). After it is washed out, i.e., the dial patterns are free of emulsion, you need to let the screen dry. After it dries, (and tidying up unwanted holes with screen filler --- see the PDF instructions), you are ready to go.

Pictures

Here is dining room set up for coating the screen before I go to yellow light. You can see the bucket of emulsion, etc. Again, you can see why it is useful to have an understanding spouse.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Screen_workarea

Here is the screen before coating. You can see how it is taped off, and the ruler is ready to go. I'll put a line of emulsion along that edge, then drag it towards me using the ruler.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Screen_precoat

Here is the setup for the screen. At the bottom is some wood, roughly to fit in the well of the screen. On top of the wood is some foam. On top of the foam is a very black bit of cloth. The light is suspended between two chairs at 1 ft above where the top of the screen will be.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Screen_lightsetup

The screen is being exposed. You can see the images on the OHP transparencies. You might also be able to make out the large sheet of glass holding the transparencies against the screen.

[Bricolage-DIY] fabrication Masion d'un cadran de montre Screen_exposure_1


A close up of one image so you can see the transparency and that it is in a mirror image. This is the side of the screen that will be on the dial surface. The inside of the screen well gives the point of view from which we will see the print.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Screen_exposure_2

The screen drying after being washed out. You can see the image which is now a stencil in the screen.
[Bricolage-DIY] fabrication Masion d'un cadran de montre Screen_drying

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Dynamo
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Dynamo

Nombre de messages : 7028
Localisation : Paris
Date d'inscription : 05/05/2005

[Bricolage-DIY] fabrication Masion d'un cadran de montre Empty
MessageSujet: Re: [Bricolage-DIY] fabrication Masion d'un cadran de montre   [Bricolage-DIY] fabrication Masion d'un cadran de montre EmptyDim 21 Aoû - 7:54

Robert L. Frazier a écrit:

Réalisation :

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[Bricolage-DIY] fabrication Masion d'un cadran de montre MIL1
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[Bricolage-DIY] fabrication Masion d'un cadran de montre Family_19Aug2005

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ZEN
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ZEN

Nombre de messages : 56533
Date d'inscription : 05/05/2005

[Bricolage-DIY] fabrication Masion d'un cadran de montre Empty
MessageSujet: Re: [Bricolage-DIY] fabrication Masion d'un cadran de montre   [Bricolage-DIY] fabrication Masion d'un cadran de montre EmptyDim 21 Aoû - 7:57

Ca me laisse un peu perplexe...La méthode semble trè strès artisanale et le résultat trop parfait...

_________________
Contraria contrariis curantur. (Les contraires se guérissent par les contraires).
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Dynamo
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Dynamo

Nombre de messages : 7028
Localisation : Paris
Date d'inscription : 05/05/2005

[Bricolage-DIY] fabrication Masion d'un cadran de montre Empty
MessageSujet: Re: [Bricolage-DIY] fabrication Masion d'un cadran de montre   [Bricolage-DIY] fabrication Masion d'un cadran de montre EmptyDim 21 Aoû - 12:15

je suppose qu'il faut regaerder le tous en vrais et pas en photo qui peuvent être trompeuse
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