works future curriculum r&d about press contact

Andy Cavatorta Studio | Dual Coincidence

Concept & Design

Dual Coincidence is an art commission for Museo Banco de Mexico (The Museum of the Central Bank of México). Andy was asked to contrast the dynamics of using barter and using money. The piece takes the form of a multiplayer game so visitors can become emotionally invested in the experience of the two different dynamics.

Andy chose to use pinball as part of the game because everybody knows how to play pinball even if they have never played.

The center of the game is the Exchange Matrix — a collection of rotating carousels that can pass balls between the playfields to simulate the dynamics of barter and money.


Andy chose to make the game profoundly physical, in contrast to the screens and speakers that surround us every day.

The alphanumeric displays are made of layers of edge-lit acrylic instead of video. The music comes from tuned chimes instead of speakers. The whole game is electromechanical, highly kinetic, and full of physical sounds.

Related design excitements: The relentless and flowing energy of Chris Burden's Metropolis II. The stylish monochrome of 2001:A Space Odyssey The beauty of precise, steel machinery. The spooky inner life of some machines.

Andy resisted both futurism and retrofuturism in the final design despite their huge gravitational pulls in a 20th-century electromechanical game full of computers.

Form & Structure

Players need to interact to trade. They may be strangers. They may not share a language. Just as with trading money.

And players need to understand when others can and cannot be interrupted. So eye contact and body language are important.

Each player can see their own score, their own game, and the Exchange Matrix. Players of average height can also see the games of others. The sightlines and buttons also welcome shorter people and wheelchair users.

And the mirrored overhead displays give spectators a glimpse into each playfield.

The structure itself is welded steel and strong enough to withstand the unpredictable forces of the game-playing public. Andy specified that it must be strong enough for multiple to dance on. Just in case.

AC Studio projects often start with full-sized cardboard mockups. They can usually be made in a day or two. They answer questions we have and questions we have not yet thought to ask.

It's wonderful to make discoveries early with an afternoon of work a bunch of leftover boxes.

The wooden prototype is strong enough to be functional and can be modified easily and cheaply. It's a testbed for ideas that will be committed into steel.

Again, our understanding and our prototypes became more detailed, it was easy to adapt and iterate.

AC Studio worked with ArDiMu in CDMX to CAD and fabricate the final steel and glass structure. ArDiMu contributed many practical solutions and delivered beautiful and precise work.


The Five Playfields

Traditional pinball playfields are surprisingly complex and nuanced. A good design must consider not just every action and reaction but also sequences and their narrative arcs.

Prototype One

Our first prototype was strictly a learning experience. The high-powered mechanisms and their timing. The angles and materials. The flow of the ball.

Prototype Two

Our second prototype was playable! And it taught us a lot about what makes a playfield not play well.

Prototype Three

Our next iteration introduced the three flippers and three pop bumpers we see in the final design. Andy continued to explore drop targets but without much satisfaction.

Prototype Four

We finally developed a playfield that flowed acceptably well. It was harder than expected! So even though it was simple, this design was our keeper.


The Final Design

The final playfields are far more complex, precise, expensive, and labor-intensive.

They start with detailed CAD models that include layers of aluminum plate, polycarbonate, and wood and all of the components, fasteners, and wiring.

The playfield substrate is a 7mm plate of aluminum topped with a 7mm polycarbonate layer. Both are cut on CNC routers and cleaned/deburred by hand.



Because of deadlines concerns about getting stuck in customs for months, all of the playfields were shipped to CDMX before they could be fully wired or tested. We would not find out if they played well until near the end of the assembly process.

Playfield Lights

Each playfield contains 72 channels of lighting. The LED animations tell the story of how gameplay accumulates goods that can be exchanged.



The Displays show the current phase of the game and each player's points.

Andy originally explored using video screens but chose a more physical and dimensional format.

The five displays use 175 channels of high-powered LED lighting to illuminate 175 alphanumeric panels.

The results are wondrous and lovely.


The musical motifs and game sounds are produced by 25 tuned metal chimes. They hang overhead through the middle of the displays and are played by powerful solenoid actuators.

Each chime was hand-cut and hand-tuned.

Several prototypes were needed to make the actuation work just right.


The final assembly was a tricky puzzle. So many structures, holes, chimes, and wires! We eventually discovered the only one arrangement in which they could all fit.

The Exchange Matrix

The exchange matrix is the most complex part of the game.

It transfers balls between the five games in a simulation of shared resources and a marketplace.

It includes the ten tubes that store and launch balls, the six rotating carousels, their 30 ball-pockets with sensors and solenoids, 144 channels of lighting, and thousands of lines of code distributed on twelve networked computers.

The R&D started with a wooden prototype. And soon we were cutting metal for the final version.

The underside of the exchange matrix features six closed-loop motion control systems and all of the wiring and computation to support the carousels above.


The carousels are rotated into alignment and exchange balls between their ball-pockets by kicking them with solenoid actuators. inductive sensors are used to infer and ensure the success of these transactions.

The carousels can be divided and combined into complex behaviors and displays.


Since they could not be fully tested until they were all working together, three whole generations of carousels were built before we found a perfect design.

Surgery on the carousels and their dozens of delicate connections still has a terrifying feeling of performing brain surgery.

This diagram portrays all of the circuitry under the exchange matrix. Sensors, actuators, computers, lights, and various interfaces.

When the game and its 17 computers are first booted, it must take an inventory to find all of the balls. This shows part of the inventory process finding thirteen balls in one tube. You can see how the game senses when it needs to retry passing the ball.

Diagnostic Interface

Such a complex machine requires a complex interface. The diagnostic and real-time interaction interface is a generative SVG display layer created and controlled from within by about 6000 lines of raw JavaScript.

It is inspired by the aesthetics of classic sci-interfaces from Alien and 2001: A Space Odyssey.

All Together Now

Andy was so engrossed in creating the game that he forgot to document people playing it. This video is edited from hundreds of phone videos shot for reference during development and testing.