Guide for Choosing Parts When Building a Skeleton Seiko Mod

Watch wearers may pay more attention to the case or dial of a watch, but for watchmakers, their pride usually lies in the movement within. The skeleton watch, a mesmerizing timepiece that reveals the intricate inner workings of its movement, can trace its origins back to the 18th century. Watchmakers of that period sought to showcase their craftsmanship by creating watches with see-through dials and movements, allowing the wearer to admire the intricate dance of gears and mechanisms that powers the timepiece. Today, skeleton watches remain appealing to enthusiasts with their unique blend of technical artistry and elegance. 

Of course, this watch trend made its way to Seiko mods as well, with plenty of skeleton parts being available in the market that allow for different builds. Unlike what the name may suggest though, these watches do not actually have skulls and spines for its motif. It may be a ‘partial’ skeleton watch that uses parts with a hollow design (usually the hands), or an actual skeleton build with a clear view of the movement without altering its functionality. Today we will talk about how you can make your own Skelly build at home, but first, let us give you more context about this particular watch design.

 

Understanding Skeleton Watches

A skeleton watch is defined by its transparency, allowing the wearer to see the intricate movement that powers the timepiece. The dial is either partially or entirely skeletonized, and in some cases even being removed altogether, revealing the mechanical components beneath. The movement itself is carefully designed and finished, with each component meticulously crafted and arranged for maximum visual impact. Here are two example watches to illustrate:

Orient Star Mechanical

Source: A Blog to Watch

 

The Orient Star Skeleton is a compelling option for those seeking a well-executed skeleton watch from a respected Japanese brand. The watch showcases Orient's in-house caliber 48749 hand-wound movement with a 70-hour power reserve. The skeletonized dial offers an unobstructed view of the intricate movement components, including the rotating balance wheel designed like a comet, and the silicon escape wheel for reduced friction.

 

Source: Hodinky 365

 

Notable details include the Geneva stripes on the movement's bridges, the subdial for the off-center hand, and the power reserve indicator. The blued hands add a touch of elegance, complementing the silver or champagne color schemes. The 42.5mm stainless steel case is hand-polished using the Sallaz method, and the double-curved sapphire crystal features an effective anti-reflective coating for optimal visibility.

While not a certified chronometer, the Orient Star Skeleton delivers respectable accuracy, with an average of +10 seconds per day when fully wound. Its allure lies in the meticulous Japanese craftsmanship, in-house movement, and unique skeleton design, offering a taste of exclusivity at a more accessible price point compared to high-end Swiss counterparts.

Grand Seiko Kodo

Source: @relogioserelogiosbr on IG

 

On the higher end of the spectrum is the Grand Seiko Kodo, a timepiece that represents the peak of Japanese watchmaking craftsmanship. This watch features the Caliber 9R92 movement, which is an in-house high-beat automatic movement operating at 36,000 vibrations per hour, ensuring exceptional accuracy and precision.

The Kodo's skeletal design is a true showcase of artisanal techniques. The movement's bridges and plates are meticulously hand-finished using traditional Japanese methods, including diamond-dust polishing and the renowned Zaratsu polishing, which is also applied to the 41.8mm high-intensity titanium case and bracelet.

 

Source: @sjxwatches on IG

 

The skeletonized dial provides a three-dimensional view of the movement, allowing the wearer to admire the intricate details and finishes of the mechanical components. The dual-curved sapphire crystal further enhances the visual experience by offering an unobstructed and distortion-free view of the skeletal display.

 

Making Your Own Skeleton Mod

Choosing the Movement

Choosing the correct movement is the most important step for this particular mod. After all, the purpose of a skeleton build is to show off the mechanism. Luckily, this won’t pose too much of a challenge, since Seiko actually already makes a Skelly movement within the trusty NH line - the NH70 and NH71.

 

 

The only difference between the two is the color, where the NH70 is nickel-plated while the other is gold-plated. In terms of looks, they both feature intricate holes and cutouts, designed to be as aesthetically pleasing as possible while retaining that mechanical charm. For functionality, you still have the respectable -20 to +40 secs of accuracy and 41 hours of power reserve.

For those seeking a more premium option, the Miyota 90S5 is the one to go with. This skeletonized automatic movement from Citizen's Miyota line boasts a higher beat rate of 28,800 bph, ensuring smoother second-hand motion. The movement is beautifully finished, with intricate skeletonization and decoration visible through the dial side.

 

 

The 90S5 features a unidirectional winding mechanism and a power reserve of approximately 42 hours. Its skeletonized rotor adds to the visual appeal, providing a glimpse into the movement's inner workings from the caseback side as well.

While more expensive than the Seiko NH options, the Miyota 90S5 offers a higher level of refinement and performance, making it an attractive choice for enthusiasts seeking a truly premium skeleton mod experience.

Choosing the Dial

When you have a movement that’s just begging to be seen, covering it up with a full dial would be a crime. There are dials with an open heart that showcase the escapement and balance wheel (aka the most hypnotizing part of the movement), but you can also opt for a dial that makes full use of the NH70/71’s design.

Our Skeleton dials are cut out to exactly match the piercings of the NH70/71, a barebones look that allows the movement’s aesthetic to shine through. It features applied, polished indices to maintain legibility despite the many piercings.

 

 

For something with a more premium look, we also have a Skeleton Snowflake dial made in collaboration with @awfulcustoms, which was inspired by the Zenith Defy and the AP Royal Oak. With such heavy hitters for inspiration, you can be sure that this will add a lot of oomph to your build!

With the right dial, you’ll be treated to a first row seat to the caliber’s swings, rotations, clicks, ticks and tocks. So choose wisely!

Choosing Other Parts

Once you have your movement and dial, you can be as imaginative as you can when it comes to the other parts, although one consideration would be to not also use a skeleton hand with a barebones dial unless it is fully lumed, or else it might be a tad hard to tell the time.

You may also want to go with a sapphire-display caseback to show off the backside of your build as well. And while you’re at it, why not upgrade your NH70/71 with a custom rotor to really elevate the look up to the nines!

Wrap Up

Building a good Skeleton Seiko mod is a proper way to flex your watchmaking skills and create a watch that will turn heads and spark conversations. By carefully selecting the right parts you can make something that’s not only a timekeeping tool, but also a miniature mechanical art piece on your wrist.

If this inspired you to take on your Skeleton watch project, be sure to check out our catalog as we have everything you need to get started! Whether it’s the skelly movement or dial, or a sapphire caseback for a good view of the back side, our store has it all for your modding convenience.

Happy modding!