The idea for building a cyclone or tornado came from seeing Ned Kahn's Tornado exhibit at the Exploratorium in San Francisco. This project was quickly moved to the back burner because of the prohibitively expensive sheets of curved transparent plastic. The project found new life when I paired a can of dust-off compressed air with the hard plastic cover from a stack of blank CDs. I poked a little hole into the side of the clear cylinder and blew air in at high speed. It worked like a charm, instant cyclone! Professional advice: Don't let your boss catch you making a desktop cyclone with canned air and the lid to a stack of blank CDs. Next, I wanted to try this on a larger scale. I had plenty of fans to create airflow, but wasn't sure how to make a big, transparent cylinder. I think Eric was the one who came up with the saran wrap idea, and I thought it was a terrific, cheap way to get the same effect. |
On the fourth of July, I invested in ten rebar stakes at Home Depot ($15) and brought a box full of supplies to Nick's party. I recruited some help and raided Nick's garage for tools. What a party! Everyone was getting hammers! |
Odie helped me stake out a circle in the ground. Next, I wrapped the stakes with plastic wrap, or rather, I pulled a plastic film curtain around them like I was wrapping a pallet full of boxes.
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Professional advice: Don't protect your chinchilla farm with a Saran wrap and rebar fence. |
The effect of one desk fan was pretty weak, and it seemed as though a lot of wind power was escaping out of the bottom and the top. I tested the airflow with styrofoam peanuts. It was pitiful.
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Luckily, Nick has an industrial carpet-drying fan.
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The industrial fan was better. I could feel the air flowing all the way around the perimeter, but styrofoam peanuts were still getting stranded in the center. Next, we stretched plastic over about half of the top, and worked to plug any gaps in the bottom with plastic or dirt. |
Smoke tests were disappointing. Smoke filled the chamber, but no one could see it flowing, it just looked like a solid block of smoke. Look! A scale model of the Beijing Olympics!
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Fireworks which threw off a ton of sparks were a little better, but not spectacular.
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One nice effect was that the captured smoke enhanced the lighting effect of almost any firework that was placed inside. |
I'm sure the neighbors thought we were huge pansies, going overboard with what looked like a firework spark-guard. |
The firework cyclone was not awesome. It was probably too big, and the airflow probably needed to be a lot stronger. Also, I took a closer look at other "tornado-makers" people have made, and it turns out that most use a completely different design. I'll have to try some new techniques next year...
Can I borrow your air-compressor? |
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July 8, 2008.