Wednesday, 29 September 2010

The Hands Part3- The Minute Hand

In a skeleton watch the hour hand is held in place by the minute hand. In regular watches the dial does this job. This complicates the design of the minute hand a little bit. What is required is a sort of pipe or collar below the hub to keep the hour wheel engaged with the minute wheel. Hands are also made in two pieces, a turned hub & a thin filed hand. But I wanted the hands for No.1 to have a little more 'meat' on the bones. Therefore these hands are one piece.

As with the hour hand, a hole is drilled & the job is mounted on a turning arbour. But in this case, a sort of 'island is turned at the hub.
The material around this island is filed away.....

..... and the hand is shaped a bit.

Now the protruding collar is turned down a bit.....

... and the inside is turned away to accommodate the cannon pinion.

Here is what the collar looks like.

The hole is broached to fit the cannon pinion.

Now, the hour wheel is 'cleaned up' and hour hand broached for a good fit.

And, finally, a test fitting of the rough hands on the movement.

I can finally begin the skeletonisation. Hope this was interesting.


Tuesday, 28 September 2010

The Hands Part2- The Hour Hand

The Hour hand for No.1 is fairly easy to make. Essentially, it is a flat piece of steel with a hole and a certain shape around the hole. The minute hand is more complex. But we shall come to that in due course.

The first thing to be done is to drill a pilot hole for the hub. This is always smaller than the required dimension and with the planed side facing down. The idea is that, provided the set up is true and rigid, the surface & the hole are perpendicular.
The job is mounted on a suitable turning arbour. In the picture below you can see a set of vintage turning arbours I acquired some time ago. These allow you to turn jobs with holes of various diameters.

Now, the correct diameter for the hub is marked on the turns.

Here it is, I like to make a marking on both sides. Also, the hole has been broached to fit the hour wheel.

The hub and the rest of the hand is filed down. Please note that the dimensions are on the larger side since some more material will be removed during final adjustment & polishing.
Finally, both the surfaces are planed once again on the polishing tool.
The rough hand is ready. It is still soft. The hand will only be hardened & tempered after final adjustments.


Thursday, 16 September 2010

The Hands part1- Preparing the Material

After all the excitement about Switzerland, lets get back to the watch!

No.1 has blued steel hands. You cannot just use any steel. Functionally the hands need to be tempered to spring. This allows for repeated assembly & disassembly (during servicing). Also, a spring retains its shape better. Aesthetically, they need to be heat blued. Silver steel serves this purpose very well. Unfortunately, I have only been able to get it in rod form. So, I must make flat bars out of the rods.

Here are two lengths of rod, one for the hour hand, one for the minute hand.

These need to be split down the middle.

The two halves...

The halves need to be filed down into bars with parallel surfaces

In watch work, a good finish is essential at each stage of work. Here are the bars ready to be worked upon.

Next time I will write about making the rough hour hand.


Thursday, 9 September 2010

Neuchatel Part2- WOSTEP

For all it's reputation, WOSTEP turned out to be a very unlikely place. It is a charming former house on the lakeside road. I was told it was built in 1907. I had expected a high rise set-up humming with activity. Instead it is a very cosy place with just 6 students in the 2 year full training programme. It is obvious they focus on quality :-)

Since I have got prior experience with watches my test was a little different. The others were asked to file a block of brass into as perfect a cube as was possible. I, on the other hand, was asked to service an ETA 2892. This is an automatic movement with (quick-set) date complication. I had never worked on this movement before. It has some unusual features e.g. the winding gears & the offset train. So, I took quite a bit of time to do this task. I am happy to say that the movement was working after I was done with it :-)

The next task was to cut a piece of brass in a 'V' shape.
like this....
And then it had to be filed so that it matched perfectly, one way......

...or the other.
Looks easy but it takes a lot of careful filing to get the two pieces to match perfectly. If the job is well done, one should not be able to see any light gaps between the two pieces.

For the last task, we were given a couple of hairsprings & tweezers.

We were asked to form numbers from 0 to 9 with the hairsprings. This was probably the most delicate task. Hairsprings have a mind of their own & there is a knack to getting the shapes one wants. Here is what I managed. In my defence I will say that my handwriting is terrible as well :-)

Apart from these three tasks, we had to fill out a questionnaire with some maths problems and questions on gears & levers. So that is what the two day test was like.


Wednesday, 1 September 2010

Neuchatel Part1- The Town

I shall split my trip to Switzerland into 2 posts, one about the town and the other about WOSTEP & the test.

I came to Neuchatel by train. Swiss railways, in my limited experience, appeared to be supremely organised and well run. All the information one might need is easily accessible. The officials are polite & well informed. The trains ran on time, literally to the minute.

Here is the station building, rather severe looking :-)
My hotel, L'Aubier, was about 10 minutes walk downhill. It is basically a cafe on the ground & first floors with rooms above. This part of the town dates back to the 15th century. Please note the clock tower, you can see it in other pictures.
The picture below perfectly shows the nature of Neuchatel. This picture is taken from the top of the prison tower looking roughly north. To the right (east) is lake Neuchatel, to the left (west) are the Jura mountains. In between is the town of Neuchatel. The roads near the lake are level but the ones near the mountains climb steeply, sometime at 16 degrees! You can see the clock tower over my hotel in the middle of the picture.

Beyond the lake, looking south-east are plains and then the Swiss Alps.

An interesting observation deck built by the lake.

Below you can see one of the ports along the lakeside road. In the background is the grand post office building.

The oldest part of town, where my hotel was, is made up of quaint winding streets. Below you can see the prison tower I mentioned earlier.

Fountains like the one below dot the town.

The other parts of Neuchatel, to the north & south of this area, are somewhat newer. All in all it is a very beautiful town. Of course, it is very expensive. I do believe that a Mcdonalds meal is a good indicator of how affordable a place is :-) A decent sized Mcdonalds meal here will set you back by about CHF 14!

Hope you enjoyed this mini tour of Neuchatel.