The Dial (part-1)

We now come to a very delicate and (cosmetically) important part of my watch- the dial. Every stage of making the dial is crucial . One slip-up destroys the whole job and you have to start over. Functionally, the dial must have the correct sized hour & minute markers, the marker track should be centred & it should sit flush on the movement. Aesthetically, the brushed finish & the radius must be carefully applied. Altogether, the dial is a very demanding part.

So, I start with a brass plate 45mm square & about 0.7 to 0.8 mm thick.

As usual, one surface is planed on the glass sheet- central relief for the arbour is drilled- holes for the retaining screws are drilled & the corners are cut off. The plate is mounted with the plane side OUT. Note, this is the under surface of the dial.

Now, the usable area is sandpapered to give it a circular brushed finish & a track is relieved for the 12, 3, 6 & 9 o’clock blued steel markers. This track accommodates the underside of the blued steel markers but it also helps with the overall legibility of the other markers.

Now the job is reversed. This is the top surface that one will see in the watch. First the central area is cut out. Then the central hole is finished to the correct diameter.

Then the usable area is faced & turned down to just over the required thickness. A little is left for the final sandpapering.

Now a printout with 60 radiating lines is stuck on the job. Please note that the job is still mounted on the attachment. The track for the markers is marked on the turns. This ensures that the track is concentric. Below you see the job with the track marked out, removed from the attachment & ready for drilling. In fact you can see that one 0.4 dia. hole has already been drilled.Everything on track so far, but with a dial you can never relax. So, this is where I am today, more in the next post.

Aditya

Movement Ring

I made two movement rings earlier this week. This means, the dial, hands and case clamps remain to be made. Here is how the ring was made-

I started with a piece of brass 50mm square by about 3mm thick.

This piece is drilled in the centre to allow the arbour of my attachment to pass. Then it is drilled sequentially for the retaining screws.Here it is mounted on the attachment. Please note that the face presented to the attachment has been planed with sandpaper on a piece of glass. A circle has been scribed as a guide to cut off the corners. The corners foul with the tool rest assembly.Here you can see that the corners have been cut off. I have also started a cut to remove the central portion (red arrow)Central portion cut off.Now the portion I want to use is faced. After this the two faces of the job will be parallel. This faced portion is then turned down to the required thickness. Also, a seat is cut for the movement (red arrow). I suppose all movements have a lip on the outer edge. This one does, so a seat must be cut for it.Now the job is removed from the attachment & tried for the internal diameter.After some adjustments & fine tuning the ring is parted off.In the picture below you can see how wasteful this method really is. A very small part of the original piece is actually used. Once I get a lathe with a chuck I could use a brass pipe of a suitable size to make the ring. This will minimize wastage.Next, I finished the outer diameter. For this the ring is held on the attachment with a plate. This whole assembly is self centring.The chamfer is turned…..
….and the ring is done.All I need to do now is to make the slot for the stem.

Aditya

Rust Removal

The question of rust removal has been discussed many times on almost all the fora I frequent. In my limited experience I have found this to be a very effective rust remover-



Yes, that's right, TEA :-). Every time I post this it is regarded as a horological curiosity. So I have decided to show it's effectiveness. I found out about this method on the BHI website. The rusted parts are soaked in a strong brew of tea for as long as required. Apparently, tea has weak tannic acid that is just the right strength to attack rust. when you soak a rusty part in tea the rust dissolves leaving off black wisps into the solution. like these screws-



Only good steel is left behind. Off course, the rusted metal is removed not repaired. So, sometimes you are left with an unusable part. I once soaked a rusty cannon pinnion- centre wheel pair in tea. The rust was removed but they did not snap together again. In this case one would need a replacement part anyway.
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So, the subject of my evil experiments is this tiny ladies "Limit of Switzerland" that I got as a parts lot.This watch is about 17mm dia not including the crown.



The balance swung fine but the train was seized. I decided to go in to practice my skills (Ladies movements, owing to their size, being much more difficult to work on). Here is what I discovered inside......

The barrel


The escape wheel


The fourth wheel


The barrel bridge


The escape wheel cap jewel carrier,


The key-less works,


.....rust at almost every pivot!

In my four years of fiddling with watches I have never seen anything quite like this. I can only guess that someone used an improper lubricant (Water???) at some point in the life of this poor watch.

So, I soaked all the parts in tea for a few hours, changing the tea once it turned murky. After this I cleaned all the parts in the ultrasonic cleaner. Unfortunately, I neither took pictures of the soaking nor of the parts after treatment.

I was pleased to see that not only does the watch work but it is also keeping time after this unconventional treatment. The point is that if tea could make this tiny movement work well (with it's tighter tolerances), then it is a very effective method indeed!

Aditya

Mugshot

Someone on the forum asked why I do not update my blog more often. Well, here's the culprit.


That's Avi, my nine month old son. He is a lot of fun but a lot of work as well! He wont let the nanny do everything for him yet, so my involvement is quite high. Having said that, it is getting better and I do get to spend more and more time at the bench everyday.

Although there is a lot to be said for working from home one of the disadvantages is that there are too many distractions. It is very easy to say "let me play with Avi for a while, the movement ring can be made tomorrow" :-)

Aditya

Winding Shaft

So, after a few days of fooling around & doing a few home improvement projects (my wife has given me a long list!) I finally had another go at making the winding shaft. I forgot to mention that I have got only hunter cased versions of the Molnija pocket watch.


The winding shaft in this one also allows for the lid release mechanism. This prevents the use of the pocket watch stem in my wristwatch. I had to measure the existing winding shaft & modify the dimensions to correct this.

Anyway, this is how the stem was finally made:

First I made cones at the end of 3mm silver steel & turned it down till it was true. I also turned the end down to 1.35mm dia.


This along with a die 1.2mm X 0.25mm cuts the required thread for my crown. It took me two days of trial & error to find this out :-)


Here is how the threads look.


Next, I turned the entire shaft down to 1.2mm (the largest sectional dia.). This is where I went wrong last time. I cut the slot for the pull out piece first. When I tried turning the shaft down it snapped at this weakest point.


Next, I measured all the features, turned the dia of the square section area that will go through the castle wheel & Cut the slots. Only the pivot is left now.


The pivot area is too far away from the centres & the shaft is too weak by this point. So, it flexes when you try to turn the pivot down. This is why I trim the shaft, turn a new cone & then turn the pivot. here is the trimmed shaft.


This way, the pivot area is near the centre & with a little bit of care can be turned down to 0.4mm dia.


Finally, I made a parting cut & adjusted the length of the pivot in the claw runner.


This is what the finished shaft looks like.


Now all that remains to be done is to file the square section for the castle wheel. The shaft will be trimmed for a particular movement-movement ring-case assembly & only then hardened & tempered. Hope you enjoyed reading this. Aditya

Adjusting end shake on a centre wheel

A post on the watchuseek forum reminded me of my J W Benson pocket watch. This watch dates back to 1892. It has a sterling silver case & an english lever escapement. It also has Geneva stopwork, an alternative to the fusee. Unfortunately, the finger piece is missing. I shall have to make it at a later date. What I love best about this watch is the loud, laid back pace at which it beats (14,400 bph). I have been fixing it's problems for two years now (as my knowledge & skills improve). The centre wheel was stripped off it's pinion when I got it. I tried re-staking it but it did not work for too long. Finally I found a replacement wheel from a junk movement. This replacement wheel was a fit but it was not as free as one would like it. There wasn't enough end shake. Finally, I was in a position to fix it. Since I was a little bored with turning all those dial markers, I decided to do this little project. Here, you can see how the end shake was adjusted on the turns. I had to turn a special turning arbour for this job. The wheel is friction fit on the arbour and this assembly is turned by a split ferrule. Admittedly, the ferrule does not fit the arbour well. But I did not find it worthwhile to make adjustments for such a small job. Also, the ferrule is one I made a long time ago. When I compare it to the one below (in the post about the winding shaft) I realise that my skills have improved marginally :-) What I will do in future is use 3mm stock to make turning arbours. I have made a split ferrule that fits 3mm stock perfectly & that way I will also be adding to my arbour inventory. Aditya

Dial marker blank

So the question was, what do I do with the broken winding shaft? The silver steel is not very expensive. It's just that I have to get it from the UK, since I have been unable to find steel suitable for watch work here in India. I hate wasting even a millimetre.I decided to make an experimental dial marker out of the broken piece. Last week I made 8 marker blanks with a 1.5 mm head (No.1-01 has 1.5mm dial markers). Here they are. They are swimming in oil because I wont need them till the dial and dial plates are ready. Untreated silver steel tends to rust in Pune climate.
Today I decided to try a 1.3mm head. Since I turn between centres (on the turns), the first thing to do was to form a new cone on the end of the broken piece. The three pictures below show how this is done.



Once you have cones on both ends of the job, you can turn between two female centres. Below you can see that the shaft of the dial marker has been turned.
After this I prefer to start the parting cut & only then reduce the head to the correct size. The under side of the head needs special attention. I make it slightly concave to ensure that the marker sits on the dial true & flat.
After everything is done the dial marker blank is cut off with a saw.


This marker blank will be finalised after the dial is ready. Please note that it is still soft.