The Mk2 Curl Curl caseback

 

One of our goals for this year was to start the journey into case manufacturing. Having made the investment in our new Kern 5 axis milling machine, the capability for making larger components from tougher materials opened up. Case-making is its own profession, its own trade. Just like there are artisans who specialise in dial making, and companies that only manufacture movements, case-making is a discipline that requires a specific skill set, specific know-how and a different kind of attention to detail. To illustrate: dial making is a discipline that is nearly totally focused on the aesthetic qualities of the time display, a small smudge, a discoloration, a scratch can all render a dial useless. From a functional perspective, however, a dial is a flat disk with some holes in it! The mechanical demands on a dial are very small, there isn't much that can go wrong, and if something does go wrong, the overall risk to the watch is very low. A case on the other hand has those priorities reversed! Anyone who wears a watch daily knows that the "factory finish" lasts about all of 2 minutes, but the "factory fit" of a watch case should last a lifetime! The role of watch-case components, first and foremost is for PROTECTION. So, when going down the rabbit hole of case manufacturing, this was the primary goal for us. Form, aesthetics, finish are all secondary- still important, but no watch collector would ever want a beautiful, perfectly finished case that welcomes water to readily flow inside! So, with that small introduction, here is the process of how we have been manufacturing the caseback for the MK2 Curl Curl. Step 1. Raw material Stainless steel 316 blanks are turned on a CNC lathe. This step is quite important as it establishes solid datums/references for all the subsequent machining operations, but also removes many of the internal stresses in the material from the raw, rolled state.

Step 2. Internal caseback machining The blank is then held in our Micro HD and the inside of the caseback is roughed out. This is actually the most important step in the manufacturing process as the sealing surfaces for the o-rings and the threads are made in this operation. These are the two areas of the case that provide all of the mechanical functionality. If the threads are too tight or loose, then the caseback is either impossible to install onto the mid-case, or the threads are not fully engaged which can present issues with cross threading, and the overall longevity of the case. Further, if the sealing surface (the area that compresses and seals against the o-ring) is not flat enough, or if the surface finish is too rough, the watch simply won't be waterproof!

Step 3. Service table engraving This feature is something we are really proud of- the service table. Many watchmakers scribe their initials and the service date into the back of the watch, this acts as the best form of solid paperwork for the service history of the watch! Providing a little table for watchmakers to scribe the date and their initials is a little nod to the future.

Step 4. External caseback machining In this step, the outside of the caseback is milled and engraved. My favourite part about this step is the stylised Curl Curl waves pattern that we engrave on the back-side! This is the same pattern that is on the dial of the MK2, but is zoomed in.

Step 5. Glass bead blasting and graining After machining, the caseback is blasted with extremely fine glass beads that provide a very even, matte finish over the entire surface. To provide contrast to the Curl Curl waves pattern, the caseback is then grained by hand on an abrasive paper adhered to a granite surface plate.

Step 6. Water pressure testing After all these steps, the most crucial QC step is water pressure testing!

Getting into case manufacturing is an important step towards our fully in-house manufactured NH watch. In the near future, we will be able to design and machine a case of any shape, size or profile, from literally any material. The capability is already here, but before we can embark on this exciting journey, we need more human hands - in-house trained technicians and machinists. This is our biggest challenge: people willing to work, to be trained and to become part of an exciting project. As always, optimistically, looking ahead! Room for expansion? Plenty! The logical step would be an investment in a Swiss-made, Swiss grade case polishing and finishing CNC machine. Like the one made by Crevosier SA. Here is a short video of this machine in action, finishing Richard Mille cases: https://youtu.be/eClSAmqpTEM I have seen this very machine in action, in Geneva; and I can't tell you what is more impressive, the technology behind the machine, polishing action or the finished product. Absolute cutting edge. How much? It's a scary number. Let me put it this way: if we sell the entire stock of watches we have currently listed on our website, we will just make it. And then we would still have to sell all our Seiko just to pay GST on import. LOL. As they say, Rome wasn't built in a day. Our time is yet to come... one step at a time!