New York City-based electrical engineer, Chris Fenton, helps design supercomputers to pay the bills. When it comes to fun, however, this imaginative maker’s forays into steampunk machines keep him both engrossed and entertained. Fenton shared on MakerBot’s Thingiverse his recent project, which he calls PixelWeaver, a fascinating, steampunk-style machine that is partly 3D printed.
PixelWeaver is an entirely mechanical, punch-card driven, bit-mapped display inspired by The Difference Engine, a work of fiction written in 1990 by William Gibson and Bruce Sterling that poses an alternate history. The book is regarded as critical in establishing the genre conventions of steampunk. In the book, Victorian-era British inventor, Charles Babbage, builds a mechanical computer–an analytical engine. One of the machines featured in the story is a Kinotrope. It has a large panel comprised of little cubes of different colors on each facet; the cubes can be spun by a steam-powered crank machinery drive called a difference engine (a titular calculating machine) which orients particular colors forward, rendering them as physical pixels in a huge display. Driving the Kinotrope is just one role of the difference engine.
The Kinotrope, inspired by The Difference Engine (1992) by William Gibson and Bruce Sterling. https://differencing.blogspot.com/2010/04/kinotrope-clackers.html
As a computer engineer, so clearly not a novice, Fenton’s working version of the novel-inspired Kinotrope has two primary components: A 32-hook, Jacquard-style punch card reader, which can be mounted over a small loom or any other device that requires mechanical control, and a 6×5 pixel, black-and-white display. What he calls a “messy web of nylon thread” connects the two components and allows a chain of cards to play an arbitrary animation across the display.
A project that Fenton had previously undertaken, the Turbo Entabulator, helped him figure out how to build his PixelWeaver. As with such generally uncharted projects, he learned as much from his mistakes as from his successes but the Turbo Entabulator ended up being an educational predecessor to the PixelWeaver.
The frame of the PixelWeaver is constructed largely from 15mm x 15mm extruded, repurposed, T-slot aluminum. The T-slots accommodate M3 nuts, which makes it easy to bolt things to them and adjust the bolts when necessary.
Fenton calls this PixelWeaver’s “world’s lowest-resolution display.”
The card reader is a single-acting, single-cylinder Jacquard machine with four rows and eight hooks. For those readers who aren’t especially weaving- and loom-savvy, that’s a particular process for weaving and a critical loom attachment invented by Frenchman, Joseph Marie Jacquard in the early 19th century, that made the automation of weaving possible. It’s particularly useful for creating complex patterns. A central drive shaft with an attached handle provides both power and timing to the entire machine, including the display.
While Fenton had formerly tried to limit manufacture exclusively or as much as possible to 3D printing, he incorporated other methods of fabrication for the PixelWeaver with 3D printing still figuring prominently. The pixels are made using a 3D printer, and a small, four-tooth ratchet wheel is printed onto one side of each cube. A hole for an axle runs all the way through the cube so that the pixels can be assembled into rows. Fenton mounted a thin ratchet arm next to each pixel and the arms, when pulled backwards, can toggle the pixel state. A flat spring holds each pixel in place while the ratchet arm returns to the resting position.
So, how does the PixelWeaver work? In essence, every pixel is implemented as a cube. The alternating faces of each cube are painted black and white. When the pixel is rotated 90 degrees, it toggles from black to white or white to black. “The design,” suggested Fenton, “could actually be extended to use color by painting the faces with different colors and sequencing through them as necessary.”
“I generated the card patterns by hand by drawing out the 4 frame transitions I wanted on 6×5 grids, and XORing the two frames together to make a 6×5 grid of pixels that need to toggle. I then mapped that to the 8×4 card pattern, drew up the cards in AutoCAD and then laser cut them out of card stock.”
Fenton noted that he still needs to do some “remapping” and to work out some bugs in the machine and in his process. If we’ve lost you in the above discussion of toggles and pixels, ratchet arms and punch cards, your interest will surely be restored when you see the PixelWeaver in action in Fenton’s video. There really is something fantastical, utterly charming and other-worldly about the hand-cranked, human driven machine whose ultimate purpose seems to be far more about evoking than manifesting.
Check out the video of the machine in action below, and let us know your thoughts on it in the PixelWeaver forum thread on 3DPB.com.
