Flashback: Random Screen

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I love low-tech emulations of high tech objects, and when they employ recycled materials, what could be better? This week’s Flashback comes from the pages of the very first volume of CRAFT, published back in 2006. Aram Bartholl showed us how to make a 16-pixel display from old cans, tea lights, paper, and wire. Check out the how-to to build your own. You can also pick up back issues of CRAFT Volume 01, a classic, over in the Maker Shed.
Turn your recycling into art.
By Aram Bartholl

The Chaos Computer Club’s Blinkenlights project in 2001 — which turned an office building in Berlin’s Alexanderplatz into the world’s biggest interactive computer display — inspired me to think and work on low-tech analog and mechanical screens.
Besides being able to play Pong using your cellphone on an 8-story-high, 18-window-wide display, it was possible to send small, self-made movies called “love letters.” This was the way my brother asked his girlfriend to marry him.
Since then, I’ve wondered how to play low-res pixel movies on a small scale without any standard screen technology, and built Paper Pixels, a punchcard-controlled mechanical analog on an 8×8-pixel screen. To push things a bit further, I started thinking about candles and pixels, and the concept of Random Screen popped into my head.
Random Screen is a non-controllable, 4×4-pixel screen run by tea candles. Each pixel is a 5″×5″ box made of cardboard, which is open at the back and closed with translucent film as a projection screen at the front. A modified beer or soda can is transformed into a kind of vent and driven by the rising heat from a tea candle, which also serves as a light source. A window is cut into the beer can, which casts the candlelight while turning at its individual frequency, like a lighthouse lantern. The brighter and bigger the candle flame, the faster the can turns to switch the designated pixel on and off. The light of each pixel fades smoothly in and out.


.5L or 16 oz. beer/soda cans (16)
1mm cardboard
or (even better) some similar fireproof material
Translucent paper, film, foil, or even glass I used inkjet backlight print film.
Stiff wire, a needle, a cable connector, a Phillips machine screw and a nut
Tea lights (16)
Step 1: Get ready.
First of all, have a good time and drink the beer (or soda). If you’re planning to build several Random Screen pixels, it might be wise to invite some friends so that you don’t get too wasted while preparing the materials. I used to store some beer cans in our shared office fridge, which is a very easy and quick way to get them emptied.
Step 2: Make the pinwheel and stand.
Cut off the top and bottom of the beer can and shorten it to 5″. For 9 vent rotors, cut from the top in equal distances 1¾” into the can, at an angle of 12°, with shears or sharp scissors.
Punch a hole through each rotor near its top end, so that the tops of all rotors can be drawn together and a screw can pass up through the holes to hold them together. This part needs some patience, and be careful. Lock the screw in place with a nut.
Then make a simple wire stand. The base should fit around the tea candle, and the other end should be bent in and up so that the can will hang over the middle of the candle. Attach a needle to the end with the cable connector, checking to be sure that the pinwheel can spin easily.
Step 3: Cut window.
Cut a 2″×2″ window in this modified can and cut in some zigzags to make the light fade in and out smoothly. Run a test and place a tea candle inside to see if the can hangs straight. Make sure that the can is able to turn freely. You might have to work and bend the material a little bit.
Step 4: Build the pixel boxes.
Cut and/or fold the cardboard to build a 5″×5″ pixel box 7″ deep. In order not to cast shadows or any movement onto the front pixel screen, make a middle wall inside the box to separate the back candle space 4″ from the front projection space, leaving 3″.
A 2″×2″ window covered with the translucent film diffuses the passing light from the candle onto the main front projection screen.
Place the stand plus modified beer can in the open back of the box. Light the candle to see if every-thing works. If you built more than one pixel, you can just stack them on top of each other. (Of course it is also possible to build a 9- or 16-pixel Random Screen in one piece, but I like to make each pixel separately as a module you can play with.)
Tip: Watch your fingers! Aluminum cans have a very sharp edge when cut. Be particularly careful when gathering the rotors together. If your can doesn’t hang straight, add some of the bits you cut out as counterweights. Feel free to move the materials around to make for the best fit and to maximize balance and spin.
Step 5: Turn out the lights!
A dark room is needed to obtain satisfying results. Light all the candles and watch your work of art flicker in the dark.
WARNING: A 16-pixel Random Screen produces quite a bit of heat, so be careful with flammable materials and never leave it unattended. Don’t burn your house down!
Resources: datenform.de/rscreeneng.html
About the Author:
In his art projects, Aram Bartholl tries to transform objects and behaviors from the digital era back to the analog, mechanical, and physical world. Read a profile of him in MAKE Volume 07, page 23.

10 thoughts on “Flashback: Random Screen

  1. donna says:

    Rather than using candle tea lights you could use either flame less ones or substitute led lights for the candles. Much easier and safer. I think it would be easier to build also.

  2. Goli Mohammadi says:

    That’s a great idea, Donna! Be sure to send us some pics if you do the mod.

  3. Plainclothes Goddess says:

    The heat rising from the candles is the energy that runs the show. Lights that do not generate heat will not turn the cans.

  4. Goli Mohammadi says:

    That’s a good point, Plainclothes Goddess. You could also use lights that fade in and out for a similar effect, but then there wouldn’t be much need for the cans and hanger. And to make LEDs fade in and out takes the low-tech back to high-tech.

  5. Николай says:

    Keep up the hard work. You do a great job. Thanks…

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I'm a word nerd who loves to geek out on how emerging technology affects the lexicon. I was an editor on the first 40 volumes of MAKE, and I love shining light on the incredible makers in our community. In particular, covering art is my passion — after all, art is the first thing most of us ever made. When not fawning over perfect word choices, I can be found on the nearest mountain, looking for untouched powder fields and ideal alpine lakes.

Contact me at snowgoli@gmail.com or via @snowgoli.

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