The Magnetic Letterpress is an immersive installation that presents personal and collected interpretations of human progress - celebrating our imaginative capacity to project into the future and imagine what may be ahead. I think of it as a ‘mechanical oracle’ - a portal onto an imaginary space in which insightful voices rise from a depthless void.
The installation was made to hold the viewer’s gaze tightly between two horizontal surfaces - a rear-projection screen suspended just above head height, and a perfectly reflective layer of mirror black oil - located just above waist height. The projected image is reflected in the oil below, but because of the space between the two surfaces, the viewer experiences the illusion of a fathomless void that appears to descend way below ground level. Peering over the table’s edge produces a sense of vertigo, a visceral manifestation of the uncertain and increasingly surreal futures expressed by the machine.
The ‘letterpress’ aspect of the installation refers to the mechanism that transforms the black mirror into an expressive medium. Underneath the table, a system of magnets interact with the magnetic oil to form words that rise up into three dimensional shapes. The words appear in sequence with the projected image, breaking the reflection to form sentences that either prompt the speaker, add emphasis, or create an undercurrent of meaning. The overall effect is a kind of continuous ‘focus switching’ - between a near-focus fascination with the magnetized words, and a far-focus view of infinite space. The push and pull between wonder and awe evokes the technological sublime - a disconcerting emotional state that parallels the speaker's reflections on progress.
The project is still a work in progress. The work of capturing the interviews is starting to gain momentum now that it’s safer to meet people in person. In the interim, I am able to share some of the more abstract sequences, made to explore the expressive potential of the medium. These will eventually be arranged between the interviews - so the overall experience shifts between the factual and the poetic.
“Let Them Not Say” is based on a poem of the same name by Jane Hirshfield, one of the USA's most celebrated contemporary poets. Performed by actor Geo Espilanty, the black mirror becomes a literal and metaphorical space for reflection.
This sequence takes its starting point from Wolfgang Sach’s essay "Speed Limits" - from the exhibition catalogue : "Speed - Visions of an Accelerated Age", from the 1998 exhibition at the Whitechapel Art Gallery, London. Partly inspired by Julian Opie’s Road paintings made around the same time, the sequence transitions between lucidity and hallucinogenic motion sickness. The music is Facades by Philip Glass.
Projected and reflected lights dance in time with this solo piece for piano, written and performed by Chilly Gonzales. An abstract intermission in which the light sculpts itself around the mounds of oil, which are in turn sculpted by the invisible lines of magnetic flux created by the magnets.
Making this installation was a complex process that included engineering 11 electro-mechanical machines, designing and fabricating custom printed circuit boards, writing Letterpress “firmware” code, and fabricating the structures that support the oil and overhead video projection.
After the machines had been calibrated and tested, I developed a system for scripting sequences that control the machine in time with the video projection. A custom made application written in Open Frameworks by Stephen Braitsch enables me to control the magnets.
These images capture some of the process engineering the Letterpress, starting with the first proof of concept prototype, and working all the way through the rapid prototyping techniques that eventually made it possible to make 180 individually controllable linear actuators move up and down in perfect synchronicity.
The magnets are arranged to produce a unique hexidecimal font, capable of producing any letter from “a” through to “z”, or numbers “0” through to “9”.
The first “proof of concept” prototype used electrically controlled solenoids to punch the magnets up and down.
The prototype was successful in so far as it showed the principle of writing with magnetic oil could work, but the movement of the magnets was too abrupt, making the oil wobble like jelly.
The next prototype used multi-threaded shafts set in bearings, spun around by servo motors. Neat as this solution was, the parts were too expensive to scale 180x (one unit for each magnet)
Someone once told me to keep an ‘inventors book’ documenting every step of the process. I ended up with 3 books, each a couple inches thick. These pages show the finished circuit board designs.
At the heart of the system - this simple motor driver circuit, capable of controlling 2 motors. My finished circuit design squeezes 9 of these onto a single board - enough to control 18 magnets per unit, and produce a single letter.
The frame design was tested using cardboard cut with a laser. The actual frames were cut from aluminum using a water-jet. Since both technologies are based on the same principle, I could be (mostly) confident that they would come together in the end.
Mechanically and electrically identical to the final design, this detailed prototype confirmed the magnets would produce legible letters and numbers, appearing and disappearing at a comfortable pace.
Switches detect when magnets have reached the maximum limit of their movement. These mechanical switches were later replaced with optical switches - which are far more robust and don’t produce a “clicking”sound.
The system includes just enough feedback to detect when magnets have reached the maximum limit of their movement. These mechanical switches were later replaced with optical switches - a more robust and quiet solution.
To help improve the legibility of each letter, the magnets are arranged with their polarity in mind, so the oil tends to conjoin or divide, depending on the position of each segment.
3D printing the magnet mounts saved time and enabled successive iterations, helping tighten the design and push the segments closer together.
One of 11 fully assembled units, showing the aluminum frame, finished circuit board design and all of the magnets in place.
The design includes several features that will help keep the installation in service - such as these motor driver chips, mounted on removable miniture circuit boards.
Using rare-earth magnets instead of electromagnets generates a huge saving in electrical power. The system makes intermittant use of 12v and 5v supplies - seen here as tranformers mounted along the base.
The overhead rear projection screen hangs on cables suspended from a secondary frame that also supports the video projector. The structure can hang from ceiling mounted bolts, or load bearing trusses.
Steve Thompson welding the aluminum structure at the Exploratorium workshop in San Francisco.
Images projected onto the overhead screen are seen reflected in the oil below.
The kinetic words interact with the projected image, flexing the light around the magnetically produced forms.
The Magnetic Letterpress is programmed using this software application - built by Stephen Braitsch using Open Frameworks. It features a timeline with editable keyframes - used to tell the system when to move magnets up or down.
This project was made possible due to the Bay Area's community of makers and engineers whose help and advice helped steer the way forward. The first prototype to come to life with help from Scott Minneman, running the machine on an Arduino Mega. Michael Shiloh helped with the design of the control circuit, which I later developed into a custom PCB. The application that connects the machines and is used to program the sequences was written by Stephen Braitsh, using Open Frameworks.
The brushed aluminum table and suspended screen was fabricated in the San Francisco Exploratorium and Autodesk Pier 9 with the help of Steve Thompson. The fabrication process was also assisted by: Carlos Rodriguez, Quincy Quinton, He Zhang, and George Grenley.