Rapid Prototyping Tornado Machine

We tried to build a tornado machine based on one of the models we found online, however we were unsuccessful. We didn't have all the materials to build it, but we were hoping to get something to work anyway. In my research I found that many people said that it was easy to get a vortex going, but much harder to make it visible. 

Helpful Research Links

Here are some links that I found during my initial research:

http://www.amazon.com/American-Educational-Tornado-Demonstration-Model/dp/B00658DTOA

(Educational Model on Amazon, about 18 inches and about $220)

http://www.teachersupplysource.com/product/60531/american-educational-products/science/meteorology/scott-resources-and-hubbard-scientific-tornado-demonstration-model/#dp_images

(Teaching Tornado, about 2 feet tall and about $190)

http://eo.ucar.edu/webweather/tornact3.html

Simple experiment with cardboard

http://www.accuweather.com/en/features/trend/how-to-build-a-tiny-tornado-diy-project/64620

DIY tornado machine

http://www.tornadoproject.com/cellar/workshop.htm

Step by step instructions for a DIY tornado machine (contained)

http://www.instructables.com/id/diy-tornado-machine/

Informative DIY video

http://www.youtube.com/watch?v=oM1FVAYE2pg

Video of large, unconfined tornado

-Wyatt