4 Ways to Make Fire Tornadoes (DIY Giant Bladeless Fan)

Introduction: 4 Ways to Make Fire Tornadoes (DIY Giant Bladeless Fan)

About: I am looking at the way the world is and all of the potential that exists in the space around us and the space between our ears. Asking questions that range from the ridiculous to the important and engaging w…

Fire Tornadoes are a popular project here on Instructables and on YouTube alike. The goal of this Instructable is to compile a few of the common ways and to explore a few new ways that I have not seen before. I am going to walk you through 4 different ways to make a fire tornado starting from the simplest possibly cheapest and then working up to what I think is a brand new way. Here are they are:

  • Spinning Mesh
    • This a common way that I have seen fire tornado be made. The simplest is to use a lazy susan(she gets such a bad wrap) and a mesh trash can. This has also been shown on some other great instructables using other forms of wire mesh to make even larger versions
  • Offset Fans
    • I have seen this way done so many times but always for big demonstrations. I wanted to see if I could use what I had on hand and make it work on a mini scale using 40mm computer fans to generate the circulating air streams.
  • Offset Tube
    • You may have seen this done with glass taking a vase and cutting it with a special tool that is very difficult. I thought that since the air is circulating around the fire that it would insulate the two half-cylinders so that we could a simple material than glass. I will show you how to carefully form 2 sheets of acrylic to make your own fire tornado
  • Bladeless Fan
    • Now for the crown jewel using a giant DIY bladeless fan to turn a fire pit into a fire tornado. Using a large bladeless fan made from a commercial trash can we installed some veins to guide the air into a rotating path which instigates our desired fire tornado!

Supplies

Spinning Mesh

Tools

  • Possibly None!
  • Marker
  • Ruler

Materials

  • Lazy Susan (Either one from the kitchen or a lazy susan element from a hardware store like I did)
  • Mesh Trash Can or Rigid Wire Mesh
  • Stand (If you are using the lazy susan element it will need to attach to something)
  • Small Cup (You could use condiment cups or I had old metal measuring cups)
  • Cotton Balls (These hold the fuel in place as the system spins)
  • Fuel (I used Lighter Fluid)

Offset Fas

Tools

  • Marker
  • Utility Knife
  • Hot Glue Gun (If you use hot glue as your adhesive of choice.)
  • Power Supply

Materials

  • Cardboard
  • Five 40mm computer fans
  • Small Cup (You could use condiment cups or I had old metal measuring cups)
  • Fuel (I used Lighter Fluid)
  • Tape or Glue ( I used Hot Glue hence the Hot Glue gun in the tools)

Offset Tube

Tools

  • Oven
  • Metal Trash Can
  • Leather Gloves
  • Parchment Paper

Material

  • Two 11"x14" Acrylic Sheets
  • Small Cup (You could use condiment cups or I had old metal measuring cups)
  • Fuel (I used Light Fluid)

Bladeless Fan

Tools

  • String
  • Marker
  • Ruler
  • PVC Glue
  • Hot Glue Gun
  • Utility Knife
  • Skillsaw (You could also just use the utility knife but it is a bit of a challenge)

Material

Step 1: Building the Spinning Mesh Fire Tornado

Take three of your major parts; the mesh trash can, lazy susan, and base board, and set them out in a table in front of you. The first and most important step is to flip the trash can over and find the exact center of the trash can. This is very important because we want to be able to have the fuel located in the middle and not wobble when we spin the can.

Finding the exact center of a circle can be a challenge but if your trash can was anything like mine it has three small nubs for feet on the bottom that can be used to use the method of drawing three cords (Lines that intersect a circle passing through the perimeter twice) and then from the middle of the cords drawing a line that is perpendicular to each of them that connects with the point that the other two cords form like what you see in the second picture.

The resulting point is the middle where all three of these perpendicular lines intersect is the center of the circle. Since I am using the lazy susan hardware to make my spinning mechanism I then measured its inside diameter to use my drawing compass to help me line up on the center of my trash can.

Once you have the center of your trash can found you can mark the bottom of the can where the mounting holes exist in the lazy susan mechanism to use come very sort machine screws to mount the hardware to the bottom of the can. You will need to pre-drill the holes in the bottom of the can so that the machine screws which have a blunt end can go through.

With the mounting holes on the bottom of the trash can complete the next step is to make the mounting holes on the base. I am using 3/8" machine screws and the 1/4" base material so it should just barely make it which is important since there is very little clearance in the lazy susan mechanism. After the mounting holes are drilled into the base we can start by mounting the hardware to the trash can.

I feed the bolts down from inside the trash can but even with 3/8" bolts they stuck out too much so I had to add some washers to the inside of the trash can to have them stick out less. Once these bolts are attached you can feed the other bolts from the bottom of the base upward and tighten all of the nuts. This has the benefit of having the heads of the bolts exposed which means it should be less likely to scratch the surface it is sitting on of tear a bag that is in the trash can if you would like to use this project for a trash can again in the future

With all of these elements installed and tightened down you are ready to perform a test spin to see that you have the trash can on center. If that is the case you are ready to go. Load up your fuel cup with a few cotton balls to help the fuel from splashing around and then put in you fuel.

Now that the whole system is ready ignite your fuel and give the can a gentle spin. The result should be fascinating a fire tornado seemingly appears out of nowhere right in the middle of your project! Great Job!

If you are interested in making a fire tornado in a different way then I would encourage you to go onto the next step.

Step 2: Mini-Box Fan Tornado: the Build

You have probably seen as many youtube videos as I have showing people making fire tornadoes using a collection of box fans. However when I look at how many fans they use and how much those fans cost it is outside the price range for something

Step 3: Offset Tube Fire Tornado: the Build

This is taking a popular method seen on many Youtube channels such as The Backyard Scientist that took a glass vase and cut it using either a glass cutting tool or a diamond cutting wheel on the dremel. There seemed like there should be an easier way to make a no moving parts fire tornado.

Since the sprialling air caught in convection keeps the fire tornado in the middle of the setup it would seem that we could use other materials for the enclosure even if they are little bit more susceptible to flame because there will be a protective current of air between the fire and the enclosure.

With this thought in mind I settled on acrylic sheeting because it is clear and easy to form if you heat it evenly and is temperature resistant to almost 200F which means that it should be stable in all but the most extreme cases.

After getting the 11x14 sheets you will need a form to help you create the desired half cylinder. I had a metal trash can that we use later in this project that has a radius of ~8" which works perfect for the 14" dimension of the sheet.

Pre-heat the oven to 220F which allows for inaccuracies in your oven temperature from keeping the acrylic from getting too hot and off-gassing too much. At the same time well ventilate your kitchen so that any gasses that do form from heating the acrylic can be dispersed quickly.

Once you have the two sides of your system formed you need to find a stable surface away from any moving air to be able to place you cup with fuel and to place the two half-cylinders around the cup slightly offset like I show in the picture. Lite you fuel and watch a spectacular fire tornado form from the circulating air currents. If you do not see results carefully move the sheets so that the are offset consistently.

Note: I have not run my set-up for any long period of time so I do not know if there are any issues with the acrylic becoming too hot and melting of catching fire. Do not leave this system unattended.

Step 4: Bladeless Fan Fire Tornado: the Build

This is using a large bladeless fan design that is contained in my other instrucable here:

https://www.instructables.com/id/Worlds-Largest-Bl...

There is a small adaption that is need to use it to generate an impressive fire tornado and that it is to add guiding veins to promote the air and the air that gets en-trained with the accelerated air into a spiral shape.

With a small modification of adding a collection of vanes at an angle to guide the air all you will need to do is place it around your fuel source and light up your fuel before you spin up your bladeless fan fire tornado.

I cut 18 of these vanes and then marked and spaced them around the fan at around 2.5" inches apart so that they are evenly spaced. Then using a hot glue gun I attached the vanes so that if you looked down from above at the edge of the fan that all that you would see is the vanes. It is better described in the pictures above.

It just so happened that I had a small charcoal grill that fit this space perfectly which actually helped to promote the fire tornado formation because it improved the control that the vanes had over the air.

Then using cotton balls and lighter fluid we lit up the fire and lit up the leaf blower to create a spectacular demonstration.

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