LutetiumAlright! Lets get started. Welcome to Hack Chat @kevin ! While we wait for people to post their questions to https://hackaday.io/event/159091-art-cars-and-flame-effects-with-kevin-bracken can you tell us about about yourself ?
Certainly! First, thank you very much Lindy for inviting me here - great to join you
I think I am probably best known for creating International Pillow Fight Day, an event that began in Toronto and has now taken place in over 150 cities worldwide
But over the last two years, my life has been fully dedicated to building mutant vehicles - first, The Prodigal Swan (which now lives in downtown Las Vegas) and Heavy Meta, our 30 foot-long fire-breathing dragon
can you tell us a bit more about The Prodigal Swan? I've seen pictures of the Heavy Meta.
beautiful!
Sure! The Prodigal Swan was our first mutant vehicle, built on a Taylor-Dunn electric warehouse cargo mover
It has a football-shaped body and a series of concentric rings for the neck, along with a flame effect in the crown
We loved it very much, but its major drawback is it could only hold about six people
Wow, super cool. Our first question comes from @Stephen Tranovich " When building an art car, what is the ideal chassis to start with? "
Great question! People have religious feelings about this, so here goes: I believe a diesel mini school bus is the best chassis, and here's why:
Electric carts are extremely sensitive, mostly because of the speed controller and the batteries. They are very prone to heat-related failure, and any number of things can set them off. Unless you are an electrical engineer, it is not likely you'll be able to find many people who can fix a speed controller in a pinch
Cars are great, especially small Japanese cars like Toyotas and Honda Civics because the parts are easy to come by and almost anybody can fix them, but their maximum capacity is small
We are metalworkers, mostly, so our tendency is to weld a bunch of steel on top of whatever we make
Mini school buses, however, are guaranteed to be in great shape when you buy them. The chassis of Heavy Meta is a GMC Savana, which is about 45% of all vans on the road. It was 15 years old when we bought it, but because we got it from a school, it was rust-free and many parts were brand new
And because they are intended to shuttle ~20 people, with the safety factors you can probably fit more like 40 people on there
or 20 people and a bunch of steel ;)
Thats a good point about making sure you have someone who can fix it!
Our next question is from @Jarrett " Flame effect fuel? Are there different kinds? Pros/cons?"
So we use propane for a few reasons. Mainly: it's extremely safe. It requires a very specific fuel:oxygen ratio to ignite, and is not prone to exploding if something goes wrong, only catching on fire for a bit
Liquid flame effects are out there, but they are more dangerous, have a tendency to keep burning/light something on fire if something goes wrong, and occasionally, trace back into the fuel source
See: cheap isopar systems, such as the one implicated in the stage fire in Belgium
Because of that, most of the trick of getting LPG flame effects right is gas plumbing! I never thought we'd become gas plumbers, but here we are
Interesting I didn't realize that. @Richard Hogben wants to know " What electric power system considerations are involved, is it similar to a normal vehicle or completely custom? "
So we have used on-board generators on both of our cars, and most people do. The alternator from a car is not really capable of powering all the things we need it to:
We have a 15,000W soundsystem, and each electric pilot light we use draws about 500W as well
The solenoids that release the flammable gas over the electric pilot lights are 12V, so we run a line directly to the bus battery for that
that's a lot of power
MAXIMUM POWER! Yes, and dealing with the heat and noise from our generator is an ongoing issue for us - we are in the market for a new one!
Question from @Lutetium and @jar
@jarrett " How do the flame effects work? Are they manual or electronically controlled? "
Sure. So flame effects in this context usually work in the same way: compressed gas is piped to empty accumulator tanks. From there, an electromagnetic solenoid opens and releases the gas in a cone past some kind of ignitor. Our ignitor is called a glowfly, it's basically a solid square of metal and ceramic that heats up to 200ºC
So here is the gas train diagram for our system:
The "hot surface igniter" is the glowfly. They are the 500W-draw electric pilot lights I mentioned before
As you can see, there are 3 solenoids in our system. When they receive a 12V signal from our control box (a series of push buttons), a little electomagnet opens the valve.
The 3 solenoids correspond with each flame effect: small mouth effect, large mouth effect, and the tail effect
In that sense, it is manually controlled. Government inspectors really like it when a flame effect cannot fire unless a human is pushing a physical button!
Haha, that makes a lot of sense for inspection. Can you tell us a bit more about dealing with government inspectors in this context?
Certainly! We have passed inspection in a dozen different municipalities, and the rules are completely different everywhere you go. Of all the inspections we've had, Toronto is certainly the most demanding, because they don't just send fire department people, but also field engineers
In some cities, they simply look at the dragon and our documents and pass us
But in other cities, we must call sometimes months ahead to track down all the necessary documents, and provide a bible-sized amount of documentation
@x asks "What do you like to use for vapor tanks, and maybe talk a little bit about the process of LPG to BIG BOOM VAPOR (puffers), do you use any particular pressure regulators along the way, or run up to full tank pressures?"
Sure thing, so the easiest thing to use for your accumulators is definitely just empty propane cylinders from Costco. You remove all the stuff on top of the cylinder and you have a nice high-pressure vessel to contain gas
We use four 40 lb. cylinders for our mouth flame effects, for example
All of our pressure regulation is done at our main system regulator, which you can see in the gas train diagram above as the third symbol from the left. We typically run our system at 20 - 50 psi
Fire inspectors will often put our operating pressure on the permit as a condition; the size of the flame depends on everything from the wind direction to the barometric pressure that day, not just the pressure the system is running at
We have met folks who run at tank pressure! That is probably more appropriate for Burning Man than a city :)
some Burning Man specific questions from @Jarrett , "Ever have any car-related MOOP disasters?" and "What if you break down in deep playa?" Whats it like having an art car at Burning Man? Any specific concerns?
Re: MOOP, Burning Man has been really good at eliminating one of the biggest sources of vehicle-related MOOP by starting Hell Station, where you can get gas, propane and diesel right in the same place, using kiddie pools to catch any drops of errant fuel
And oh yes, we did break down in deep playa once with The Prodigal Swan. Two batteries exploded molten lead inside the battery compartment! This was part of our decision to move to something more reliable, aka DIESEL POWER!
And what is it like - well, one of my motivations for doing it was I never felt like I ever saw enough of Burning Man
>wow, that sounds like a tough situation
Last year was the first year I ever didn't feel that way! Totally worth it.
What are some of your favourite flame or art car pieces? What should we know about in the world of flame art?
Sure, so the big granddaddy of vehicles with flame effects is definitely El Pulpo Mechanico - the octupus
but in 2017, the creator decided to modify it to a vehicle called Rabid Transit
One thing that is really near and dear to my heart, though, is mutant vehicles with flame effects built outside of California
The one I'm most excited about this year is the Ark of Orenda, built, improbably, in Lansing Michigan
It's 50' long built on a transit bus, clad in aluminum and painted with copper. this year at Lakes of Fire, its flame effects were synced up with the Tikis at Funky Tiki Tea Hut for a truly spectacular fire show
what is Ark of Orenda going to be?
here she is! with our dragon in the back :)
Thats amazing! What is next for Heavy Meta?
We are about to get into a very aggressive tour schedule! July 14 is our biggest party in Toronto yet, Metaverse at the MOCCA development site outdoors
Then a festival in Quebec, and then Detroit Maker Faire
after that, Burning Man prep, and then we are in talks with about half a dozen other Maker Faires in the US
which takes us basically to November. I'm exhausted just thinking about it!
Thats amazing! Sounds like a busy summer.
Thats about it for Hack Chat I think. Thanks so much for your time! I learned a lot about how this all works.
You're all free to stay and talk, but the official chat is over.
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