Slayer Spar – Designing an Espresso Machine in Three Dimensions

support

Mar 03, 2009

skeletonSlayer deploys a magazine of multiple tanks in a cylindrical cluster, similar to the barrel configuration of a Gatling gun.

Slayer’s tanks are mounted to ribs which are attached to a central spar.  This happens to be the way the wings of almost all fixed-wing aircraft are made.

However, our inspiration was not Boeing, though aircraft design and construction did play into our thoughts. Nor was it guns.

Nor was our inspiration the human anatomy, where a highly specialized skeleton is enclosed by the body, while the body provides higher level functionality and sensory support, but not raw structural strength (for this kind of thing see, insects and arthropods).

However, analogies from nature that dovetailed with our thinking were validating.

The fact is Slayer’s tank mounting system was based on practical, real-world considerations.

Like so many other features of the machine, the choice of a spar began with a question. In this case, we asked ourselves, what is the best way, the most efficient way, to configure cylindrical forms in a machine that preheats water for brewing as well as steam, provides an independent tank at each group, and was designed to never lose capacity even at full output from all systems?

aircraftPerforming the geometry revealed how ungainly a conventionally configured machine that could pull this off would be.

Conventional machines are built on a platform, located as close to the bottom of the device as possible. This is essentially a two dimensional configuration. From this platform small risers or brackets support tanks. Around this base a scaffolding structure is erected to provide rigidity and additional places to mount components. Sheet metal or plastic panels are also mounted to this scaffold. Some newer machines substitute heavy body panels instead of a frame. However, this can result in flex issues when sheet metal is relied upon to support heavily used components. Over the course of 10-15 years, it is almost certain that machines like this will wear out from fatigue.

Slayer plays in a three dimensional space, x, y and z. The spar allows the use of the z coordinate when it comes to mounting tanks or recovering lost space below the deck for other purposes. Since the spar runs through the machine, it is possible to consider the placement of components in their ideal location, no matter how high or how low in the defined space. Slayer’s preheat tank which has lower operating temperature than the steam and brew systems is mounted above the other tanks. This placement has operational benefits, and also allows the passive recovery of heat from the brew and steam tanks and improves efficiency.

buldings

The architecture of tall, modernist buildings played into our thinking and offers a good analogy for the design and application of the Slayer spar.

Large buildings rely on a strong central shaft containing the elevator and essential services to provide most of the structures support for perpendicularly mounted floors. The outside walls of these buildings are sheaths of glass, marble or concrete, and provide none of the structural support, but a lot of design flexibility. Taller buildings even of modest size would be impossible without this concept, a concept which comes down to us from the Bauhaus School as it turns out. Someone on Slayer’s team has a funny, clever thing he likes to say when it comes to this design idea, “it’s all about Mies“. But this is another story. Isn’t it Dan?

For the espresso machine, Slayer adopted these architectural concepts and literally turned then on their side.

This form factor also allowed us to space the cross members (the floors) evenly so they would accommodate tanks of different lengths. Looking inside Slayer, you will count four evenly spaced cross members in the two group, and six evenly spaced cross members for the three group and so on. It’s a pattern as predictable and elegant as that of a nautilus shell.

Best regards,

Eric Perkunder
in Seattle

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Slayer Corporate Headquarters

PHONE: +1 206.284.7171
707 Lind Ave SW, Renton, WA 98057