Wednesday, 26 May 2010

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

Saturday, 15 May 2010

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.

Friday, 14 May 2010

a silly mistake

Today I tried making a winding shaft for 02. Unfortunately, I made the slot for the pull out piece at an early stage with the result that it snapped into two while I was turning the other features. Here is a picture

This is the reason why I am maintaining a log for 02. I have made this mistake before & if I had documented it I could have saved half a days work. The log will be a sort of a detailed account of how the No.1 skeleton watch is made. So, I can read up the bit on winding shafts before making one for 03 or any subsequent piece. Over time & with practice I hope this knowledge will become intuitive.
Anyway, I thought I might show you how I started work on this design. First of all, I required a 3D CAD model of the movement I had selected (the molnija 3602-3). Since I am an industrial designer I am fairly proficient with Rhinoceros (a 3D modelling software). So that is what I used. Below is an image of an early, incomplete model.

A 3D model would allow me to see the movement in a totally different perspective. I could also try as many designs/ themes with endless variations relatively quickly & without even touching a real movement. So I think the few weeks it took to make this model were well spent.
The No.1 is a skeleton wristwatch. In the image below you can see the theme I selected. I wanted to lay bare the workings of a mechanical timepiece. What better way to do this than to accentuate the escapement.? Over time I developed this idea further through other devices (e.g.. finishes).

Below is a 3D model of what the watch might look like. The case was imaginary since, at that stage, I had not selected one for my watch. This went through endless revisions, each element was changed & refined till I was satisfied with it. Mind you, the true test is when you finally make it. I had decided on a certain dial marker on CAD (after days of trying options & refinement) but it just could not be finished properly when I actually made it.
I hope I have better luck with the winding shaft tomorrow.

Wednesday, 12 May 2010


Hello & welcome to my blog. As the title suggests this blog is about making watches. I have been fascinated with mechanical timepieces since early childhood. A little over a month ago I achieved something I have been working on for two and a half years, I made a watch myself.

Well, actually I took an existing mechanism, modified it, made some new parts & found a nice case for it.

Sounds simple but it took two years of part time & three months of full time work to achieve. All the same, on top is a picture of the first piece of my No.1 skeleton wristwatch. This one is 01.

I have started work on 02 & will share the step by step journey on this blog.

I also plan to share other watch related stuff here. I have collected quite a few antique pocket watches over the years and plan to share interesting features & stories about them on this blog.