Wednesday, 21 July 2010

The Dial (part-2)

So, we had pasted the template on the dial and marked out the position of the marker track. Next is the slow and tedious job of drilling/ milling out the 60 holes for the dial markers. First I drill them all out with a 0.4mm bit & then mill out the hour markers with a 1.0 mm end mill.

The blued steel markers will fit through the 1.0 mm holes. Absolute accuracy of alignment is essential, since the eye can detect even the minutest of deviations.

A lathe with an indexing attachment or a CNC mill might make this job easier. I even must explore laser etching. Now, the sticker is removed, the job is remounted on the turns and the final finish is applied to the dial. After this, there will be no further opportunities to do so.

The ring is parted....

....the outer diameter is turned down.....

...and the dial is done!

A close up shot.

Hope you enjoyed this. Plating is all that remains.


Monday, 19 July 2010

Luch Ultra Thins

I saw a beautiful 14k Poljot ultra thin on another blog, here
(Russ, I do hope you do not mind me posting this link)

So, I thought I might share my Ultra thins. They are branded Luch but I believe they use the same movement as the Poljot. Of course, these two have plated cases, I wish they were solid gold :-)

The gold one got a service as soon as I received it. Here is what the insides look like.

Since I sweat a lot, I destroy plated cases in no time. So, I made a little case protector for this watch out of an old wallet.

Admittedly this is not a 'dress watch' look but at least I can wear it without worrying about the case.

Saturday, 17 July 2010

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.


Friday, 9 July 2010

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.


Saturday, 3 July 2010

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.
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!