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007 Pilot Special

The story of a Seiko SKX007 Diver's watch learning to fly

Figure: Seiko SKX007K2, the starting point

Case Holder

The first thing to do is to open the watch - a hardwood block was turned into a case holder. Some drilling, sawing, sanding, a spring and two old bolts resulted in a beautiful tool.

Case opener1
Figure: Case holder

Case holder
Figure: Case holder with SKX007

12h Bezel

The idea was to create a 12h Bezel (Figure 1) with minute markers all around. A bezel like this didn't exist so it had to be made in DIY fashion.

The first step was to draw the design by CAD.

12h bezel
Figure: 12h bezel

Next a mask (artwork) was printed for the photo etching process with a laser printer on transparent foil.  The base material for the bezel was 1 mm Alucorex manufactured by Bungaard. It has a presentisized layer over a black anodizided surface, which will react to UV light. The printed mask is simply placed on top of the aluminum and then exposed to UV light for 3-8 minutes, depending on the light source intensity.

Alucorex and mask
Figure: Alucorex with a blue protective sheets and the printed artwork.

Then the exposed Alucorex is dropped into the developer and the etching process starts. The developer will first develop the image of the artwork, which will dissolve and then the  developer starts to eat the anodized surface away from those areas. Brushing the surface lightly speeds up the process. After etching the parts need to be cleaned with acetone to remove the presensitized surface, as it will otherwise react with the cutting fluid used later and your perfect insert will turn yellow.

Developing alucorex
Figure: Developing Alucorex - the artwork just starts to show.

Now that the graphics are ready on the alu sheet, the bezel needs to be machined to final shape. This is the tricky part - the chances are pretty high that the alignment will be wrong. After several attempts a simple fly fly cutter and a press drill worked ok. The alignment of the pilot hole was the key to success.

Figure: Machining the bezel with a fly cutter.

The edges of the bezel were smoothened with sandpaper until it was a snap fit to the bezel.

Figure: Fitting the bezel insert.

The hole for the lume dot was carefully enlarged, until the the dot fit snugly into the recess from the bottom side. The inside edges were then painted with black enamel.

The bezel itself was made bi-directional by bending the ends of the bezel locking spring. This resulted in a click bezel without a locking function.

Case Back

The case back was sterilized with a lathe.

Figure: Lathe work on the case back

Figure: After the lathe

Next came a small trial to result in a finish called "perlage" or "engine turning".

The tools for the first try were a small cylindrical polisher from Proxxon/Dremel and some universal polishing paste. Two wooden blocks with some index markings were used to get everything aligned and to feed the case back step by step. The polishing paste wasn't a success, as it polished just the machining pattern of the lathe and didn't leave any marks of it's own. Next a coarse engine valve lapping paste was tried and it did wonders - now the polisher was leaving a tiny cylindrical pattern of it's own, which mixed nicely with the lathe machining pattern.

Figure: Grinding the case

Figure: The result.

Black day/date

The SKX007 had a white day/date wheel, which was changed to a black one. On the movement there is a metal plate holding the date wheel, which is attached by three 1.4 mm slotted screws and a tiny "Phillips" head screw. Removing the Phillips screw was ratcher complicated - the smallest Phillips screwdriver in our local watch tool shop was 1.5 mm - which was huge compared to it's intended counterpart. It was made fit with the help of a small rectangular nail file, which was used to make the tip of the screwdriver sharper. After numerous careful tries the tool finally fit and the screw gave up.

Figure: The tiny Phillips screw with the modified screwdriver


The basis for the dial was the Bill Yao Sub model. One requirement for the project was to place the crown on the left side, which required turning the dial upside down.  The dial feet were slightly unsymmetrical to prevent mistakes in production -> off went the dial feet - snip!
Dial feet
Figure: Cutting the dial feet

Then a nice date window position was defined around 4 o'clock which wouldn't interfere with the lume/markings. The space between the date markings was assumed to be 360/31 deg, which turned out to be correct.

Next a mask was printed with the correct date position on two transparent overhead foils. The dial was sandwiched between the foils and secured with some scotch tape. The purpose was to create a drilling and filing jig. The foil also protected the face in case the tools slipped. The position of the pilot drilling wasn't important, it just had to be inside the date opening.

Dial work
Figure: Dial with mask

Figure: Dial with pilot hole.

Then a special tool was prepared for the filing work - a sandstone was used to polish one face of a rectangular needle file completely smooth. The polished face of the tool enabled leaning it to one side of the rectangular opening without cutting into it while working on the other edge.

The edges of the date opening were painted with black enamel to finish the work.

Figure: The finished dial
Mounting the dial to the movement upside down was fairly simple - two recesses of the movement holder were filled with three layers of thin double sided adhesive and the dial was carefully placed in position.

Dial mounting
Figure: Adhesive to secure the dial


The original crystal was pushed out and changed to a Yao sapphire crystal. During the process the chapter ring index markings were sanded away and the ring polished, leaving it plain black. 


The hands of choice were Yao "plongeur" type of hands with some modifications.

Figure: Plongeur hands, with tail and lume dot already removed.

Plongeur dial
Figure: Modified plongeur hands

It didn't take long to notice, that the hands/dial combo don't work together. The dial markings at 3, 6 and 9 overlap with the plongeur hour hand with the result, that it suddenly looks optically like a very looong minute hand turning the minute into an hour hand.

The hands were therefore changed to Yao "MOD Sword" hands.

Plongeur at six
Figure: The hour hand turning into the minute hand.

End Result


Project SPIN-OFF(s)

Initially the idea was just to do one watch, but in the end... well you know. Here are the best 007 Pilot Special side dishes.