We’re very happy to be installed in our new double-wide container in The Shipyard. In case you haven’t heard of The Shipyard, it’s really an incredible facility run by Jim Mason and Jess Hobbs. There are huge machine tools, mini “hardware stores”, ample common areas for building large-scale sculptures, and shipping containers where resident artists can store their wares.

One of the best things about being over there is everyone’s willingness to show us around, show us the quirks and conventions of using a gigantic lathe, or help install a capacitor to get the drill press working. And that’s even after we accidentally busted up a couple projects on move-in day! It seems it’s a constant shuffle moving huge items around. Luckily there’s a forklift that could literally lift a house to manage the work.

We’re in full production for Priceless this July 4 weekend and Fire Arts Festival coming up July 9-12. At Priceless, PyroCardium will be pulsing to heartbeats in its original spiral form. Ben is creating massive colored flame effects in the river for a new project called Toxic Bloom. We’re bringing along “Sputnik”, our custom heat exchanger to power a River Hot Tub. And I’ll be teaching a Flame Tree Workshop.

“Sputnik” heat exchanger on the Ocean Beach flower bloom heating our inflatable hot tub.

Ben tests an accumulator effect for Toxic Bloom.

For a while now I have been talking about hooking up the Emotiv headset brain computer interface (http://emotiv.com/) to the Pyrocardium and this Thursday we managed to pull it off.

What you see in this video is me in a headset actively trying to turn on the fire with my mind. You can tell I am trying to turn on the fire by when I am holding out my hand. I find using a gesture generally helps me focus on a very precise thought. The thought to turn on fire in this case was to imagine the look and sound of the fire and “will” the fire into existence using psychic energy coming out of my forehead. I realize the part about the forehead energy sounds a little flaky but the neat thing is that it works quantitatively better.

To get to this point, I trained the system to recognize the thought pattern for setting things on fire with my mind. This was done using software Emotiv distributes to developers. I took the output of this software, interpreted it some, and then wrote to the USB controller board that runs the Pyrocardium. And then fire happened!

A few other people (Wanda, Kurt, Zack, and Bash) were also able to try the headset and make fire with there thoughts. They seemed pretty pleased with the results. : )

Also, in the video is Zack spraying color fire stuff into the flame to turn it red. Neato!

Oh, and big thanks to Bash who brought the headset, software, and laptop that allowed all this to happen.

Ethan managed to turn fire a bright red color using strontium chloride salt dissolved in water. He dispensed the salt with an airbrush nozzle powered by a small air compressor and we tried on several flames including a large propane venturi flamethrower as shown in this video.

Hi-Def Version

A while back I posted about my first attempts to make a stethoscope amplifier as an input to PyroCardium.  This has worked well, though it has required some tweaking since then. First, it turned out that the resistor network used to power the electret mike and to bias the output signal to within the range of the single supply op-amp I’m using was too low resistance, and was substantially loading the relatively high impedance output of the electret. Secondly, getting a good seal between the microphone and the stethoscope tubing is critical for getting a decent signal out. Tweaking those things gave us a setup that worked pretty well for Alchemy and Maker Faire.

That said, there are some definite problems with our current stethoscope/microphone setup. First, it turns out it’s surprisingly hard to position the stethoscope on your chest to really pick up your heartbeat, especially as our current setup doesn’t have audio feedback so you can hear whether you’ve found it or not. Secondly, the stethoscope does a pretty good job of picking up ambient noise.  It works great it a quiet room but less well at a noisy, crowded event.  In fact I was able to get it to trigger on the beats of the music playing at Alchemy with just a little tweaking. This is great for some other things we have in mind for Priceless but less good for picking up your heartbeat.

So, we’d like to find a better system for Burning Man.  Ideally we’d like something where there’s no ambiguity about where to place the sensor and a sensor that robustly picks up your heartbeat, regardless of environmental noise, the fact that you’re running in place, or anything else.  So far we’ve had two ideas - use some kind of simple EKG system, or use a pulse oximeter.  This weekend I tried building this simple EKG circuit but met with no success whatsoever - all I could see at the output was 60 Hz line noise.  I’m not really sure why (the high common-mode rejection ratio of the instrumentation amp is supposed to take care of that) but I’m not sure I have the skill set to make it work.  I’m also not sure that this EKG system will be robust enough or easy enough to use on the playa, and there are also safety issues with hooking it up to a line powered system.

So, my current plan is to buy a cheap pulse oximeter and see if we can rip it apart and get it to interface to a PC.  If anyone out there reading this knows about pulse oximeters and how to do this let me know.  Also, if you’re good at analog design and want to make the ekg circuit work, that would be good too :).

Watch the video.

Reporter: “So then what application do you have, besides the entertainment factor?”

Brett: “Wait, what?”

Brendan: “OTHER than the entertainment factor? What are you talking about?”

Brett: “Don’t get me started on the transition between the sense of human curiosity–”


Reporter: “No no, that’s excellent–”

Brett: “To explore the physical properties of nature–”

Reporter: “Right, but don’t you have something like, it’ll replace rocket ships to go to the moon?”


Brendan: “No it’s more like, even on the moon people will need something fun to do… and slightly dangerous. It’s more along those lines.”

False Profit Labs is proud to bring The Hydrogen Economy and PyroCardium to Maker Faire. Especially now that our circuitboards work! The last few days have been a bit harrowing, since the first time we fired up all twenty of our the flame effects, we blew up our power supply. Kurt Thorn revisioned the electronics in 24 volts DC instead of the high-voltage AC line we were using and at 11:30pm last night PyroCardium came to life.

We’re jamming a lot of technology into this project of computer-controlled fire. The little sculpture is a prototype, with a 20-foot-tall spiral to follow for Burning Man in August. It has 16 flame effects, each a small propane venturi flame pipe with a solenoid valve. All the flames are fired individually by a USB-connected driver board controlled by a False Profit Labs software application that runs various flame algorithms. Each algorithm changes the response and patterns of the flame. And at Maker Faire on Saturday from 6-10pm you can place the PyroCardium stethoscope on your chest and see your heartbeat race up the sculpture in a spiral of flames.

PyroCardium’s first test-run

Flame Tree Workshop participants at Alchemy light up their creations:

photo by broxtronix

I’m teaching a Flame Tree workshop at Alchemy on Saturday, April 26 after the Fashion Show. In this 2-hour construction class, you will get to build your very own propane flame effect. It’s called a propane burner, one of the simplest to create, and produces up to about 25 flames with 4″ tails. You will be provided with all materials and tools, except your own propane which you can pick up at any hardware store.

Here are some pictures of Flame Trees that people made at our first workshop:

Skills you’ll learn include: plumbing gas lines, making a flare fitting, leak checking, hardening and drilling copper tubing. Send mail to brett at false dash profit dot com if you want to sign up. The class is $40 and includes a free Alchemy ticket.

When planning to fill a large enclosed chamber with hydrogen, oxygen and propane, and allow members of the public to voluntarily ignite the contents, we find it’s best to consider ways to decrease the likelihood of blasting out four foot by eight foot sheets of shattered polycarbonate at hundreds of feet per second. If you plan on igniting flammable gases for amazement and amusement (read: art), you really have to consider safety third, and certainly no lower than that.

We’ve taken a number of measures to reduce the risk of life and limb, the most important of which is the hydrogen chamber itself. There’s a lot less chance of someone burning their hand, face, neck, neck, chest or faux fur costume if they are physically separated from the fire by a plastic barrier.

But again we come back to the question: How do we avoid blowing up the chamber? The key is to understand what the maximal flow rate in cubic feet per minute (cfm) is of our bubble blowing devices, and the flash point of hydrogen. Hydrogen becomes flammable in air at concentrations of just 4%. So we built an air blower and duct system that creates positive pressure inside the chamber at roughly 50-100 times our hydrogen usage. In our case, our bubble machines will consume 3-4cfm of hydrogen. Therefore we have installed a blower system that will push around 400cfm of air into the chamber. This reduces the maximum hydrogen concentration in the chamber to less than 2%. In addition, we’ve mounted many nichrome ignitors (see Ben’s last post) to ignite any small pockets of hydrogen, either contained by or not contained by bubbles, before they can collect into a dangerous situation.

How would we know if a dangerous situation occurs before the gigantic explosion? We mount a detector on the wall of our chamber, at a level where we would want to shut down the project if gas somehow pooled from the ceiling down to the detector mount point. If the detector goes off, the project is shut down until the chamber returns to safe levels.

Chris wrote previously about building nichrome wire ignitors. Now he’s got it perfected, and built a cloud of 20. What better to do than put the new bubble machine underneath?