Good morning folks,

Another couple of weeks down and progress is grinding. One step forward, and the realization that, much like with any race, the first minutes are easy. It’s eking out the final few tenths of a second which are the most difficult and expensive.

Months ago I’d machined the first version of the watch case while I was in Vermont. It was a rough draft, more or less to see how things would fit together and if the seals would fit and function. I’d been putting off the second iteration of that while working on the cnc and the dial and hands which that was responsible for making. But with those parts reaching a point where I’m no longer figuring out how to manufacture and just need to actually do the cutting, it was time to revisit the shell for this lengthy and expensive dalliance with horology.

V1.0 of the case was 11.5mm thick, which, while not terrible for a waterproof watch, is a little larger than I would like to wear. So I went back to CAD and figured out how and where I could shave off a few millimeter fractions. The main point of height savings was the top of the watch where the crystal fits in. By sourcing a better double curved sapphire crystal I was able to push the top bezel down towards the dial and still give clearance for the hands. I also pinched a bit off the bottom of the case and wound up dropping 1.4mm in total so the watch now sits at what I think is a more comfortable 10.1mm in thickness. It’s not a Skagen but I rather like the way it looks. I’ll get this version completely assembled to see how it looks in the flesh but it’s possible that I could get below 10mm on the final cut.

*V1.0 on bottom and V1.1 above with the raw water jet cut side face left on, this will get polished off on the final version.*

*A cutout drawing of the watch in its current design state.*

I took these drawings to the machine shop and proceeded to cut version 1.1 of the case. It’s been months since I turned the last one and I’d forgotten a couple of things learned in that process. So I managed to chop the strap lugs shorter than they should be and broke a 1mm drill off while drilling one of the strap holes. So it’s not destined to sit on a wrist but is going to be a good test bed for the sanding and polishing post machining process and also be a closer to final case that I can ship out for the water pressure testing.

*The point where I should have switched to the milling machine to finish the strap lugs and not cut them 1mm to short…*

With the dial, I made another two fully machine dials which I’ve been using to experiment on the coating, painting and polishing steps. In doing so I realized that my CNC’s XY bed needed adjustment so a day was spent tearing the bottom end of the machine down to the nuts, tightening a few bits, lubricating everything and then recalibrating it. It’s much better but ultimately I’ll need to find or build a larger CNC mill to take on some of the heavier cuts that I’d like to do in the future. I’ve been trying those on this little thing and while it’s very good at precision, it’s a delicate little thing, definitely not suited for cutting with end mills over 0.5mm in diameter.

Last night I spent time experimenting with various paints which will be used to fill the markings in the dial. I’ve tested numerous ones and ultimately I think I may settle on making my own. I want the paint to be very thin so it doesn’t completely fill the lines and also durable and very opaque. Mixing titanium dioxide with an acrylic varnish and thinning that down to a water consistency seemed to work. I also like the ability to add pigment this this mix and adjust the color as I like.

I’ve also been tinkering with different varnishes for the dial. The black oxide which I’m using to color the main section is a completely flat matte which I love but it’s also incredibly fragile and marks easily. I wanted something which will leave the visual properties of the finish while also allowing the watch to be assembled and repaired in the future without destroying the coating. It’s going to take more refinement but by thinning out a varnish and dipping the whole part I think I’m going to get something which works.

*New case with a lightly polished black oxide dial. you can see the small marks on this since it was uncoated. I’m trying to get a deeper black and flatter appearance.*

With the hands I’ve been struggling mostly with the second hand bushing. A tiny tube of brass which connects to the steel hand and then press fits onto the second hand pinion of the movement. The part measures .4mm in diameter at its smallest and 1mm in length. I’ll probably need to setup a mount to put my microscope over the watchmakers lathe to allow me to make these with more precision. And then practice, practice, practice.

*The first fitting of an hour hand to the hour wheel of the movement.*

Have a good week, stay warm, say hello to the dogs, don’t be a dick unless there’s no other option, and I’ll check back when I have progress to report.

Giles

Ps. Thank you folks who emailed me with interest in buying one of these. I’ll reply to your questions this week.

Part VII - V1.1 The final straw(s)