Notes on Apple's September Special Event

On Tuesday 9 September, Apple executives took to the screen to showcase the company’s newest products: new AirPods, three new Apple Watches, and four new iPhones. I don’t doubt if you’ve made the decision to read this post, then your newsfeed has also been filled with various rehashings of Apple’s press release on these devices.

In the deep corners of the internet, though, are more insightful looks into what the Apple presenters didn’t mention in as great detail. I hope this post falls into this latter camp — it focuses on the use of additive manufacturing in what (as far as I know) is its first application at such scale.

I should preface this piece by mentioning I watched the event live in its entirety as I have for the last decade. Clearly, I have my priorities straight.

The presentation opened with one of my favourite quotes from the late Steve Jobs. A designer who agrees with a declaration of design values — how surprising, I know. Fully aware of its strengths, Apple followed this with a series of clips that highlight how incredibly seamless its ecosystem ties together. No matter which flavour of technology you prefer — desserts or fruit — it’s hard to refute Apple has mastered the design and implementation of the consumer technology ecosystem, driven by both motivations of the walled garden and user-centred variety.

Kim announcing the Apple Watch Ultra 3's 3DP housing.

Almost thirty minutes in, though, Eugene Kim, a senior executive, said something that piqued my interest:

Come again?

Apple will sell millions of the Watch Ultra 3, so choosing additive manufacturing seems like an odd choice.

Till date, 3D printing has been known for its higher cost and sometimes longer production times at mass scale than traditional manufacturing methods like milling or moulding. This drawback has been offset by 3D printing’s customisability — there are no moulds to work with, which reduces costs at small production volumes and allows for use cases such as rapid prototyping.

All these factors would make it seem that 3D printing is unsuitable for use in any mass-manufactured hardware that a company like Apple produces. Apple offers no customisability in its product housings, nor is it producing at small enough scales where mould tooling or CNC tooling costs are a hurdle.

The shell of the Watch Ultra 3 isn’t the only thing Apple announced as having leveraged additive manufacturing: In its press release, Apple said the Air uses a 3D-printed USB port. This time, Apple shared greater detail on its rationale.

I wonder if the engineering team was backed into this decision, being unable to find an off-the-shelf part that met the traditional requirements combined with the new space constraints specific to the Air.

To the best of my knowledge, all of the off-the-shelf USB-C receptacles use a steel housing, and I guess Apple made the switch to a titanium port for its higher strength-to-weight ratio. Of course, a 33% reduction in material use is nothing to ignore, either.

This may hint at the team’s rationale behind opting for 3D printing for the Watch Ultra 3: Any measurable decrease in material use will add up to significant savings at Apple’s production volumes.

I stripped down an Apple Watch Ultra housing to find out its mass: 12.46g. The measurement was made on calibrated analytical balances in a controlled environment.

It seems that Apple uses the alloy Ti-6Al-4V in its CNC-milled titanium products (although this alloy may be different for the 3DP parts). Assuming the alloys cost about the same per unit mass and assuming a cost of $50 per kilo, the first-gen Ultra housing would cost 62¢ in raw material.

Of course, this is a vast oversimplification: We do not know exactly what Apple’s cost per kg is, nor can we assume that all of the waste from the original billet will be reused. And of course, tooling and engineering costs will play a significant role in determining the final cost of manufacturing that part.

Nevertheless, even if 3 million Watch Ultra 3 units are sold, this reduction in material use represents a $613,800 saving (carrying over previous assumptions). There will also be secondary savings by reducing shipping weight, although I imagine this is marginal given how light the housing is to begin with.

$613,800 may not sound like much, but savings like these, made repeatedly and iteratively over years of product development, add up and over time can significantly increase the margins on a product like the Watch Ultra. It is exactly this sort of optimisation that has defined the Tim Cook era at Apple. It is also entirely plausible that this investment in a new 3DP process will pay greater dividends in the coming years.

In summary, I remain fascinated with this breed of design and manufacturing innovation — as much as the scriptwriters for the keynote presentation skim over it. Who knows where we will find 3D-printed parts next in mass-produced products?

Till the next one,

- Yuvraj