May 29, 2007

Fire Tubes

I did three things for Flipside... I made fire tubes that dance to music, I made blinky lights patterned after fireflies, and I made some neat t-shirts. I already talked about the t-shirts. I'm not GOING to talk about the fireflies until that article comes out...

...so here is a look at the tubes!

Fire Tubes

I am going to assemble a lot of still pictures and how-to stuff on my website soon (ish) about the tubes. They are dead simple, but very pretty to watch. Improvements this coming year will make them even better, I hope!

The first two nights, I burned through four 20-pound propane tanks, slowly and frustratingly, as they froze up and lost pressure repeatedly. Short nights both, really, Friday and Saturday. But still, the tubes got a pretty good response, and people liked them. I used the quick-release junctions to good effect, rotating the half-full tanks into service every ten minutes or so.

Sunday night, K. offered up two 100-pound tanks, each of which was about 1/3 full (from what I could tell from the frost that soon formed on them). These tanks provided wonderful performance, and are in use in the video above.

I ran for _hours_ Sunday night. People watched the flames. I swear I heard cheering that coincided to particular flame actions, but I can't be sure since most of the audience was masked from my view.

People danced near the flames; one graceful lady (known to , it turns out; a fire dancer who I also saw before the big burn) was especially entrancing. The flames were used in ritual (one man offered up what looked like strips of mushroom to the flames before ingesting and moving on). People thawed out and dried off with the flames. People played in the flames. Nobody got hurt! Well, I did make the flames jump once and fried the arm hair off of one fellow, but he was okay.

All in all, it was wonderful, to be able to contribute to the experience of so many people. I love fire, and to play with fire for so many hours, and provide fire for other pyros, was a good thing.

Everything worked perfectly, too, with the tubes standing up to wind, rain, drunk people, bugs nesting in the stands, everything! I covered the speakers with plastic bags and taped over the holes (or rotated the tubes so the holes faced down) when it rained.

The HVAC metal, thin galvanized steel, held up to many hours of continuous burning. The top got hot, but the bottom never got too hot to touch; and the expansion chamber by the speaker was always cool (helped, no doubt, by the icy propane constantly flowing into it).

There was one moment of sheer panic Sunday night, maybe a half hour into the performance of the tubes. At one point I noticed that the cross-fader wasn't working on my mixing board; I would kick it over to tone to make the flame jump, just playing with it, and there would be a delay in the response. After a few times of this, it seemed like the signal wasn't getting to the tubes at all, in either music or tone positions!

My particular mixing board is known to have a weak point in the cross-fader; this part is easily replaceable for a few dollars, so not really a big problem. But if it had failed NOW, and me with no spare part... I was worried! I had a lot of propane to burn through that night, and if the flames just _stood_ their like ordinary fire... I would be mortified! Hundreds of people could walk by and see my failure!

As I was working up a good panic, my eye alighted on the dials of my lovely new power supply; the power supply that was feeding 12 volts to the car-audio amplifier. The voltage needle was pegged above the 15 volt mark. The amp needle was at zero. Fifteen volts! My amplifier! Had I killed it? Did someone bump the voltage knob? But no, amps were at zero...

I fiddled with the knob. I turned it on and off. I turned off the amplifier. Nothing changed.

Maybe the power supply just died, and everything else was okay. The lights on the amp looked good, after all. Now that I think of it, I don't know why there WERE lights on the amp. Eerie.

I leapt into action! Screwdriver in one hand, I took the power supply off the amp. I rifled through boxes, desperately looking for my battery, my charger, and something else that I couldn't find and now I don't remember what it was. But I found it. Sliding the battery under the table, I took the wires from the junction bar (you don't want to know the makeup of this frankenstein contraption, really) and screwed them into the power studs of the amp. Jumpering the battery to the charger, I click it on and heard a satisfied hum from its transformer.

All good. I turn on the amplifier again and... it worked!

Now I just have to return this defective, broken, cheap, abused, power supply. It _should_ have been able to take the jumps in current draw! It never said to NOT pound it from 1A to 15A as the audio thumped away. Nope. Not that I saw.

But it killed it good.

And yet the show went on.

Posted by Edwin at May 29, 2007 09:28 PM
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