I made, with major contributor Brett Doar, the Wilderness Machine for Chris Milk's The Wilderness Downtown movie, part of a project for the band Arcade Fire. More information will appear here later.
(I evolve web stories slowly over time; this is basically a document and it takes a while to develop the text.)
The Machine ends up with a subset of the handwritten cards generated by people on the Wilderness Downtown website. They are transferred into the bowels of the machine via sneakernet. The Machine then reproduces the cards using a pen, then somewhat indifferently tosses the completed cards onto the ground.
The machine is scratch-built from steel and bits of Cold War surplus tek. Central to the machine is the curved steel platen that holds the card for writing. It's shape is inspired by how one holds a postcard in one hand; curved in the palm it is given strength. The cards are rough and somewhat irregular, essentially "hand made" paper embedded with birch seeds that make it a tough medium for a person to write on, never mind an 'old' machine of iron.
The Machine is a little ersatz factory. It begins with a stack of blank cards on the left.
The picker arm (on the left with the aluminum nozzle head) puts the rubber stamp (that says "www.TheWildernessDowntown.com") over the inkpad, raises the elevator, which opens the inkpad door and inks the stamp. The stamp is applied to the top card on the stack. The stack of card raises up to the nozzle which sucks up the top card and transports it to the curved steel platen. (The curve was formed by hand and over my knee, and is within .015" of a perfect 6.5" radius.) Little steel bails clamp the card to the platen.
The platen drops down into the realm of the pen arm, mounted within which is a fairly ordinary pen. There is a lot of subtlety in the pen handling, a closed loop servomechanism controls pressure of pen on paper. It is here that the card image is rendered, stroke by stroke, each stroke and arc exactly mimicing the original human artist's mouse strokes (really).
(The machine hints to its technical activities on the front panel; the meter shows instantaneous pen pressure and the two green lamps show X (pen) and Y (platen) motion. The orange digits (Nixie (Burroughs Corp, brand, logn defunct) count the number of micro-strokes.)
When a card is complete, the same nozzle that delivered the card now retrieves it. It holds the now-drawn card up in the air, where the delivery hand, which we call the Ricky Jay, picks it up and delivers it to the outside world. Though the machine is blind and uncaring in it's protective shroud, a slot has been conveniently placed to allow the cards to exit.
The force-feedback pen car system. The tiny servomotor pushes the pen assembly to and fro on the pen arm. The leadscrew is threaded through the small brass block that presses against the spring, that in turn presses against the pen arm and shaft. The spring compresses when the pen presses against the card; more pressure equals more spring deflection. The brass block contains a CdS photoresistor with a pinhole that receives light through a stationary pinhole and and old-fashioned lamp (the filament of which is carefully aligned with the holes). As the spring deflects the pinholes misalign and the CdS cell derives a proportional signal. (The lucite block houses two reed switches to indicate the limits of pen car travel.)
Not very obvious is the anti-snag system. The pen is mounted to a light-weight aluminum holder that is mounted to the pen car via four adjustable springs. This allows the pen to deflect side-to-side and up-and-down when the sharp pen point hits a seed or rough card. There was a design for an active snag-detection scheme (another optical sensor) but it wasn't needed. Plan for the worst, hope for the best.
The Machine was largely fabricated by hand, plain old fashioned metal shop craft. My shop has a Jet mill-drill and now a Hypertherm plasma cutter. We literally wore out many of my files on this project.
Various ugly hacks and test rigs were made to proof things out. You gotta test before you make!
A lot of time went into details. Fillister head screws were used exclusively. I couldn't find any without zinc plating so that was stripped off with ferric chloride (yuck).
This old power supply was the first base for the Machine, but was nixed a few weeks later in favor of a custom wood cabinet.
Here are some mockups of a card-exit scheme prior to adding the Ricky Jay. There is a lot of wiring; about 80 wires lead from the controller (hidden in the cabinet) to the mechanism above. Sensors and actuators.
This ludicrous linkage allows for 180 degree rotation of a shaft. It's simple, just a crank, but the second one 90-degrees off prevents binding that would occur at 0 and 180 degrees, if there was only one of them. It also allows motion of the levers over the end of the shaft, though we didn't need this here.
Eventually it started printing out cards.
This is the Ricky Jay support structure. I'm not sure how many people appreciate how tough it is to handle paper in a machine -- and we had two robot arms handing off a card to each other.
Arduino Mega controller, plus support electronics: VN02 high side drivers, serial-interfaced Pololu servomotor, RC servo, and stepper controllers. It was driven by a mini-ITX-based Ubuntu box hidden in the cabinet.
Miscellaneous images. Note that the flimsy pen-arm motion system shown above (lead screw with teflon blocks) that I made was replaced by a more robust one that Brett made. It's more rugged and precise, and is isolated from the lower deck so it shouldn't bind if the machine gets dropped hard.
Machine craft and art work is largely tedium -- repetitive small, fine manual actions that accumulate into objects. There literally is no substitute -- some things can't be mechanized. Sometimes you just have to shape metal by hand. This isn't production, it's turning one idea into one object.
Filing metal is very much like dancing; it involves your whole body. That 'simple' vise and table is anything but; the vise might be my most important tool. A good one is half a kilobuck, and doesn't come from Harbor Freight. The table top weighs 100 lbs. They are the other half of the equation. Both of them were honed by skilled people over time. On my side of the file is practice, practice, practice. It never comes out exactly right. Shaping matter is a spiritual act with physical manifestations. There's not much 'flash' here, but it's where the guts are. Shut up and work!
Fabrication of the 3/4" thick acrylic shroud, the plinth, and final assembly at John's.