Instructables
Dossier #2 from the Graffiti Research Lab: the Electro-Graf. An electro-graf is a graffiti piece or throw-up that uses conductive spray-paint and magnet paint to embed movable LED display electronics. The following pages describe the materials and processes used to create the prototype indoor and outdoor interactive electro-grafs created in the lab at Eyebeam.

Check out the Graffiti Research Lab site and watch the DIY Electro-Graf Vid or the G.R.L. flickr group for more on the elctro-graf.

Step 1: Materials/Parts List

The basic materials for building an electro-graf can be purchased using a combination of online vendors and local hardware stores. A small (100 LED, 4' x 4 ') electro-graf could run ~$100. A large piece could cost as much as $2000 dollars, but thats just a WAG.

PARTS

Part: Super Shield conductive spray-paint
Vendor: Less EMF
Average cost: $22 per can
Notes: this is the secret weapon.

Part: spray-paint, color your choice
Vendor: I use Krylon from the local hardware store
Average cost: $22.50 for 6 cans
Notes: use what you like.

Part: Magnet paint
Vendor(s): Less EMF for premixed indoor paint called Magic Wall or Magically Magnetic, Inc. for paint additive. This additive can be mixed with indoor or outdoor primer sealer.
Average cost: Magic Wall @ $29.95/quart; Magnet paint additive @ $15/quart and primer sealer @ $8.50/quart
Notes: I used Zinnser BULLS-EYE primer 1-2-3 primer sealer for the base paint on the outdoor electro-graf proto. It's the good stuff. Your local hardware store is sure to have a thick outdoor primer that will work. You can get worse paint for less money. Note: Don't believe the hype. The paint itself is not magnetic. It is just metallic and magnets adhere to it.

Part: 10mm LEDs. The color choice is yours.
Vendor: Again, it's my crew Denny, Ann, et al. @ HB Electronic Components.
Avg. Cost: $0.20 per LED
Notes: you can use smaller LEDs, but it's just not my taste.

Part: 1/8" Dia. x 1/16" Thick NdFeB Disc Magnet, Ni-Cu-Ni plated
Vendor: Amazing Magnets
Cost: $9.00 per 100 magnets
Notes: Cost reductions for larger quantities

Part: Power supply.
This will vary based on number and types of LEDs, circuit design and environment. You must supply the LEDs with >= 3 volts DC power. Depending primarily on the number of LEDs, you can use anything from a $2 9 Volt to a $50 dollar car battery to a regulated 500 Watt power supply if the proper current limiting components are used. In the lab I use a regulated DC power supply. We will discuss this more in the following steps.

Parts: Tape
Vendor: your local hardware store should have painter's tape and masking tape. Get both.
Cost: $2-$5/ per 60 yard roll
Notes: 3M painter's tape is blue and has less adhesion than masking tape. Both tapes are useful in different situations.

Parts: 5 minute epoxy
Vendor: your local hardware store should have 5 minute epoxy
Cost: $5 dollars for one tube
Notes: This is some delightful shit. Get the kind in the two part dispenser.

Part: Stencil materials -- Acetate, Manila Folders.
Vendor: Your local art store or office store should have acetate, cardboard and file folders.
Avg. Cost: $10 for a 25' x 12 ft. roll of acetate, folders and cardboard vary in price and is often found for free.

Part: Stranded wire
Vendor: Jameco
Cost: $3 per roll
Notes: any 18-24 AWG stranded hook-up wire will work. Solid core wire is too brittle.

OPTIONAL

Part: 1/4 or 1/2 Watt resistors, the choice of value is yours
Vendor: Jameco
Avg. Cost: $1 for 100 pieces

Part: 3/4" Foil Tape
Vendor: Newark In One
Avg. Cost: $18 per roll

Part: Conductive Epoxy
Vendor: Newark In One
Cost: $32.00
Notes: The epoxy is optional. It is used to attach magnets to electronic components and wire.

Part: you can add electronic components to create LED sequences, animation, solar power, etc. You may need stranded wire for connecting your LED traces to various power sources.

TOOLS:

a respirator, a mutimeter, paint brushes, containers for mixing paints, exacto blades, clay
 
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ranex8 years ago
could you use that conductive spray to make cheap printed circuitboards
thats a good idea
This is nice, the LED are now more appreciated than ever. It is the new cool thing. Thanks to all new colors that have been added to the palette. Ionizer air purifiers use them too, not only for display, but for air purification purposes.
OK weather or not soldering the LED to the magnet, damages the magnet - IDK-
I have never managed to get solder to hold to anything outside of copper and the leads of the electronics... I've tried to solder (carefully) to those 3volt button cell batteries and I couldn't get the solder to hold, I have also tried to solder to steel and couldn't get that to work either.
quakefiend4 years ago
A much cheaper way to do this would be to use glow-in-the-dark spraypaint in the areas that you would use LEDs.
zwild17 years ago
Brilliant- Great Idea. But how can one so well versed in science such as yourself throw political BS into an instructable? Totally unrelated and irresponsible.
mrdepo96 zwild14 years ago
  I agree. I was looking for an Instructible not an opinion.  
josf5 years ago
you repeat a lot of pics
Congrats and nice piece of work.
Gjdj36 years ago
Haha, congrats on being on I Want to Work For Diddy.

The one redeeming quality to that show! Lol.
sockmaster8 years ago
By the way, you can save time and do away with the mess of having to use epoxy and/or conductive epoxy by simply soldering your wires and LED pins directly to the magnets. Solder bonds very easily to nickel plated magnets (and likely silver plated magnets too.)
Q-Branch (author)  sockmaster8 years ago
Do not solder to magnets, especially rare-earth magnets. Temperatures over 80C will damage the magnet and reduce or eliminate its magnetic field. I have tried using various heat sinks, fluxes and techniques to accomplish the task mentioned above and each has resulted in a damaged magnet.
It works amazingly well for me. There's no damage to the magnet or reduction in it's magnetic field. I've only tried this with nickel plated rare-earth magnets - but I imagine it ought to work work with silver plated magnets too. Here is what I use to solder wires or LED pins to nickel plated magnets: -multicore solder -250 watt soldering gun with a tinned tip -a metal surface or any other way to keep the magnets in place Pre-coat the wire with solder first so that it will bond quicker when you solder it onto the magnet. Preheat your soldering gun. Hold the wire and some solder over the magnet, then quickly touch the gun to the point you want soldered. It takes less than 1/4 of a second. The magnet barely even gets warm.
soldered_magnet.jpg
Q-Branch (author)  sockmaster8 years ago
1. Anecdotal evidence is the enemy of science. How are you measuring the magnetic field before and after soldering? I would suggest, though the magnet still "sticks" to things, that you ARE damaging the magnetic field significantly enough that it will no longer be useful w/r/t the magnetic field needed to adhere to the magnet paint used in the electro-graf project.
2. The Curie Temperature of rare-earth magnets is 500 degrees F. This is the point at which the magnetic field of a magnetic material will reach zero due to heat excitation. The magnetic field will be significantly decreased with temperatures greater than 176 degrees F. Due to the high thermal conductivity and the small size of the magnets, you WILL damage them if you solder using any technique. No soldering technique will prevent this damage. You must introduce heat to the magnet to cause the solder to flow. I will note I have a hand soldering certification from NASA and from Mi-6, which is to say I have a good deal of experience with current materials and techniques.
3. Sockmaster you're beaking rule #2: don't damage the hardware.
Q-Branch (author)  Q-Branch8 years ago
Just to be fair, the way sockmaster is using a metal surface to hold the magnet creates a heat sink. A heat sink helps prevent temperature damage when soldering. The problem is, depending on the impurities in the materials used, NdFeB can be as thermally conductive as steel, tin and impure nickel. And the melting point of solder is typically around 300F and this is about the median temperature between damaging and destroying your magnet. Sockmaster keep inovating. There is plenty of room for improvement in the design. The attachment method and location of the magnets is an area ripe for innovation in this project. I am only suggesting that the soldering iron is not the right hammer for this non-nail.
One of my all-time favorite quotes: In theory there is no difference between theory and practice. In practice, there is.

(I'm sorry guys, but I just have to post this--meant in fun!--or my head will explode!)

YOU CANNOT DO x.
look! look! i'm doing x!
NO, x IS IMPOSSIBLE.
but i've been doing x for some time now.
YOU ARE MISTAKEN.
(posts picture inflagrante-del-X-o)
YOU ARE VIOLATING THE LAWS OF NATURE (BUT KEEP PRACTICING)

(all humor aside this is still a way-cool project and very inspiring!)
"But I've been doing X for some time now" *stifles laughter*
sorry but I don't believe that a short exposure to temperature change will reduce the effectiveness of a rare earth magnet. its not like your using a bloody blow torch are you? are you?
"Anecdotal evidence is the enemy of science." So you're going to discourage experimentation? Even if it damages the magnetism somewhat, if it still achieves the ultimate goal of sticking to the magnetic paint, what's the problem?
sigmaz7 years ago
I'm wondering if I can get a copy of the schematics or find out if Twin A is selling his boards? I dig the patterns and It'll sure save time putting together my piece.
twina sigmaz7 years ago
i can't give out those schematics/patterns, sadly, BUT i will be developing a totally open-source AVR-based 32-LED controller board this summer, and an open-source system for controlling hundreds of lights in 16 RGB LED modules.
troykyo twina6 years ago
I can't wait to see that. I so got a project that needs that kind of lovin. We love you A!!!
twina twina7 years ago
I'm using a Tiny2313 into either a STP16CP05TTR (doing the PWM in the AVR) or for more PWM channels I use a few of the TI TLC5940 PWM chips. If you're running patterns in the microcontroller, you'll probably want more flash memory...The larger chip on the electro-graf board is one of the ST chips, and it's being driven by a PIC18F242.
sigmaz twina7 years ago
Hey TwinA.. Can you at least tell me which chips you used? I have been tinkering with a 2313 but I can only drive 12 channels with it.. it looks like you might be using an AT90WPM but I cant figure out the larger chips role.. Email me if you can I have some questions.
I think the idea is genius and execution is possible (for rich people) but maybe a combination of standard spray paint ing and conductive epoxy could be more effect, think no magnets, no magnetic paint and as long as it keeps its conductivity over distance. Another experiment or two could be based around EL wire (if you could get really fine stuff) or maybe a computer that is thinner than any other in existence (think the 2D computer, stencilled on sheets of paper, then folded to make your laptop that can be recycled with the daily paper. (oh and high tech business cards (for made at home ones anyway...) Final idea ould be doing a brick wall and lighting all the mortar lines making a magice wall (plus having it in the crevices would make a handy electrical grid and make it way harder to remove)
oops. on closer inspection they look about 6mm. But still...
That qty of ultra bright 10mm blues would have drawn a fair amount of power for somthing so exposed. I would have used an AC sorce for somthing this big - is there a large battery hiding under that pile of stuff?
Robotguy7 years ago
Adding a third trace and a "one-wire" network to this would greatly expand the possibilities. Imagine being able to individually address the leds from a central point, or add a light sensor to turn everything off during the day. Heck even a proximity sensor so the thing only lights up when someone gets close.

See http://www.maxim-ic.com/1-Wire.cfm for the list of one-wire products. I don't work for Maxim, just thought this would be a nifty addition.
infared0678 years ago
i was wondering if anyone knows if there is such a thing as like a "blacklight led" if you had a few and used flourecent spray paint i bet that would be pretty cool
There are, indeed, blacklight LEDs. I have a bag of them on the desk in front of me, as a matter of fact. If you look on ebay you can find these being sold cheap directly from China (search for ultraviolet or UV LED). Just don't use them for any application where they point right at people's eyes!
Q-Branch (author)  Eriswerks8 years ago
Check out this fine tutorial on building a scorpion detector with UV LEDs. I think LSDiodes is the best name for an LED company I have ever heard.
way too expensive. just buy led cristmas lights and take them apart. real cheap.
sumguysr7 years ago
this would be incredibly cool if someone used capacitive sensor pads to create an interactive electrograf
blksheep8 years ago
This is a beautiful idea. Great project.
chuckr448 years ago
Yes, I bought a UV LED from LSDiodes and it works great. Although we didn't find any flourescent rocks with it. And only some species of scorpions flouresce under UV.
grobelaar8 years ago
soldering certificate from Mi-6 now that I would like to see?
InvaderEvan8 years ago
woah woah woah 5 words bread-board-on-the-wall a little bit of breakout board+magnet setups and you can do anything on the wall just tape lines and have sections of conductive and non-conductive wall in lines like breadboards
maffiou8 years ago
This is so cool... And very well documented: Well done...