Hello, I would like to share with you guys a little adventure of mine. I will try try keep text to minimum and instead let the pictures speak. Anyway, a short introduction is needed: I choose, as part of the training to become a watchmaker, to make a skeletonized watch from an ETA 6497/8 movement. Also I was offered to complete the project on the The Finnish School of Watchmaking 'Kelloseppakoulu' in Helsinki. And yes, of course I wanted to go, still being young of age (dare I say; compared to most people here on OF). So, I decided to go and get the best out of it! Please, as this is the first time I am doing this, bear over with some of my techniques that are improvised or thought up in lack of both time and knowledge. This is the ETA caliber 6498. Compared to the ETA 6497 the 6498's second wheel is placed as you would typically find it on a wristwatch at 6 o'clock. (Displayed above) The first tools any watchmaker or micromechanics student must produce to graduate from the first year out of three. Some use only 3 months to produce these tools, others up to 9 months. It comes to a big advantage having micromechanics around watchmakers as you share knowledge, techniques and, most important, machines with each another. To gain some real life experience customers are invited to bring their watch in need of repair to the school every Tuesday. Students will then proceed to make any necessary repair or service to make the clocks functional and beautiful again. The price of a service at the school is the same as it would be in a regular watchmaker's shop. Back to the project! And yes, I did just call it a 'skeletonized' movement. But as the bridges came more or less directly from the factory the barrel bridge and train bridge were not separated yet. I decided to keep it this way as I have always been in fond of 3/4 bridges. So, as you can see not much material has been removed. A college of mine decided to keep barrel, train and balance bridge together. This will make the whole process of assembling the balance and adjusting it very challenging. But at least he can call it a skeletonized bridge Actually, this bridge did not make it, as there is too little material surrounding the barrings and the whole thing would be too unstable. Here, making the bridges ready to enter the blasting machine. Small aluminum pieces will be sprayed onto the sides and add a matte finish to it. To maintain a sharp edge, the top is covered with scotch tape. Here an early morning shot of the class room which can contain 14 students, making the total number of watchmaker students 3*14=42 at the school. Being that there is over 100 applicants each year, the motivation even for young students is very high. Doing some tests for the Côtes de Genève finish. Normally you would need a high precision partly automatic machine with a sanding disk designed for the purpose. I had hoped that such equipment was at hand, but it was not. Instead I used this excellent German Shaublin cutter with a mill end cutter. Just setting up the damn thing for tests was a pain in the a$$.. Setup time: 6 hours, execution: 20 minutes! Quite happy with the result, although calling them Côtes de Genève would be blasphemy... Adding some snail-like-finish to the crown and ratchet wheel. Subject and cutter spinning opposite directions. Polishing the sink of the bushings with a wooden stick and some diamond paste. Took some time to get the curvature of the stick just right for each sink. Gilding with gold and silver. First you add a gold layer to the subject. The reason for this is that silver will not attach as well to brass compared to gold. A bid sad after the gilding because something went wrong and next day a layer of dirt appeared on the surface. And it is impossible to get off... I called a goldsmith for advice, but she simply told me that they ship everything out the house for gilding, as it is a difficult process and the outcome very hard to control... A little preview of the movement. Still missing some screws, wheels, jewels, a balance, etc. You might notice that the balance bridge is slightly more yellow. To get the color right, the bridge went through another gilding process... That was it, happy to be able to share some of my experiences through this great forum, thanks. Please ask any question or add a comment you have on your mind. I will follow up this thread with more pictures as the project comes along, cheers. PS: Sorry for my broken English
Wonderful to see such craftsmanship still being passed on. I am sure it is an enjoyable process once you get the hang of it and when it doesn t ltake 6 hours to set up the machine Did you get to look around Helsinki? It is a nice city. My wife is from Finland and I have visited a few times, but only once to Helsinki.
Fantastic contribution, thank you. I would love to see more contributions from you and the school. PS your English is fine
Wow, great write up, and thanks for taking the time for that. Very good to know that those skills are still being trained and passed on. Hope to keep us updated?
Amazing post & great read. I may have the guts to try this one day. It would be something I'd enjoy, or really really hate
Thank you all for the great response! I will make sure to follow update this thread with new stuff soon. Right now I am modifying the curvature of a hair spring to fit a screw balance... Not so fun the first, and so far I have already wasted a couple of hair springs Thank God for the learning graph