9. Dilation - Completed Design
After churning through multiple iterations of the dial, index ring and overall packaging design within the constraints of what I can get manufactured and assemble without needing special tools or processes, I am finally happy with the design.
I call this design ‘Dilation’ after the phenomenon of time dilation. As you can see from my previous posts, the watches of Hajime Asaoka have influenced the design of the dial and the hands. Having looked at several images of the movement, the opening at 6 o’clock on the dial is sufficiently large to show some of the interesting components of the movement and several of the 21 jewels that are used in the 8N24 Miyota movement.
The back of the watch will have a display case back, i.e. a back cover that has an opening so one can see the entire movement. This style of case back is very popular with mechanical watches because of how interesting and intricate these movements are.
I would have liked to use smaller screws and a more elegant case back design, but for the sake of simplicity and cost I’ve kept the design modest and all the screw threads the same size as the ones I will use to constrain the lugs.
The watch will be waterproofed by using an o-ring between the case back and the case, as well as o-rings on the crown’s stem. The top crystal will be epoxied to the case, sealing that interface.
As you can see from the exploded view below, there is a second o-ring (in orange) on the movement holder. This is simply to take up tolerance in machined diameters between the case and movement holder and provide a little shock absorption for the movement. I have not seen any other watch that does this, so I need to prototype it to make sure this is not a bad idea. One negative consequence to doing this can be that o-ring eventually degrade with time. I plan to use high quality silicone o-rings that are designed to withstand harsh environments and temperatures. Hopefully those will not degrade.
Next Steps:
Get all the components 3d printed at 3x scale to sanity check the assembly.
Get some subset of components 3d printed at 1x scale to get a feel for what they will be like to work with at that scale.
Render a couple of different color schemes and start practicing enamel painting.