Automated Air Cannon With Videos

Many years ago I found the Airzooka toy for my kids. They loved the effect of shooting each other with balls of air. Then one day we had a fog machine out and used it to fill the airzookas with fog. We found that the fog effect of shooting air rings was a hole other level of fun! After this I decided I could build a much larger version of the toy and connect a fog machine to it. However, after making the original version I found that sitting in one place shooting the Air Cannon by hand got a little boring. That's when I decided to Automate it! Here's how you can do it too! I felt this would be a great Instructable to provide a perspective on mechanical automation.

As a note this project was complete about a year ago. So the pictures are of the completed project as I did not take pictures while building the Air Cannon.

Tools and materials you will need to complete this build:

Tools:

Angular Grinder

Drill

Screw Drivers

Hand Saw

Fog Machine

Materials:

Circular trash can (a plastic or metal can will do nicely) - https://www.lowes.com/pd/Magnolia-Brush-20-Gallon-...

Windshield wiper motor (used off ebay)

DC motor speed controller - https://www.amazon.com/Controller-DROK-Regulator-G...

One Large heavy duty trash bag

Lots of duct tape

EZ-FLO 1/4-in ID Latex Hose - https://www.lowes.com/pd/EZ-FLO-1-4-in-Inner-Diame...

Scrap 1/2 inch plywood

multiple sizes of screws and bolts

5/8-in dia Coarse Steel Threaded Rod (at least longer than the diameter of the trash can) - https://www.lowes.com/pd/Hillman-5-8-in-dia-x-6-ft...

Eye hook screws - https://www.lowes.com/pd/Hillman-Steel-Screw-Eye-H...

Aluminum Solid Angle bar stock - https://www.lowes.com/pd/Steelworks-1-1-2-in-W-x-1...

PVC pipe

Multiple sizes of gears (at least one large and one small) - ebay

Basically an airzooka is a plastic cylinder that releases doughnut-shaped air vortices — similar to smoke rings but larger, stronger and invisible. The vortices are able to ruffle hair, disturb papers or blow out candles after travelling large distances. This is accomplished by pulling a volume of air into a cylinder via a loose plastic sheet connected to a elastic band. When the elastic band is released the volume is forced out of its plastic container, the shape of the container's edges creates a toroidal (or doughnut-shaped) effect. I've since seen both extremely large and very small versions of the Airzooka.

The first step is to prepare your trash can. This is a pretty easy step. Simply cut a circle out of the bottom of the trash can but leave about 3 inches of the bottom near the outer wall of the trash can. I drew a circle about 3 inches from the edge/wall and then cut along the line with a jigsaw.

The next step was to create a diaphragm/loose covering over the original open end of the trash can. To do this I first placed a large heave duty trash bag over the opening and taped the trash bag to the outer edge. Without any evidence and because I like to over engineer things, I quickly came to the conclusion that even the heavy duty trash bag would not last long so I covered the trash bag with duck tape.

At this point I needed a way to connect the Latex hose to the trash bag/duct tape diaphragm. To do this I found a couple scraps of plywood and bolted the scraps together with one piece of the plywood scrap on each side of the diaphragm. This scrap plywood gave me a solid point to attach an eye hook screw to each side (inside and outside).

Next I bolted two eye hook screws to the inside of the trash can near the new opening that I had cut. This is where I connected the latex hose as seen in the pictures.

At this point your basic Air Cannon is complete. You can pull back on the plywood scrap creating tension in the latex hose. When you release the plywood scrap the latex hose will pull the diaphragm forward quickly and create a quickly moving toroid of air which can be felt across the yard in calm conditions.

However, this is not where the project ends. :)

This was the fun part. I needed to create a mechanism to pull back and release the diaphragm over and over again. This was accomplished through the following steps.

First, I needed to create a framework for the automated system to connect to. I bolted some extremely long aluminum solid angled bar stock to each side of the trash can (first picture). These started out about 2.5 feet long on each side. I figured I could always cut off any excess but you can't make it longer.

Next I drilled one 5/8 inch hole near the end of each of the aluminum solid angled bar stock bars. Then I threaded the long 5/8-in diameter Coarse Steel Threaded Rod between each of the drilled holes. (second Picture).

Then to hold the Threaded rod in place, I added nuts to the end of the threaded rod on both sides (picture 3).

Once I had the frame in place I added a small gear to the 5/8 in threaded rod (1st picture) and used nuts to secure the gear in place on the threaded rod.

Next, I was able to add a large gear to the windshield wiper motor and then simply bolt the windshield motor onto the aluminum solid angled bar stock. I only needed to drill holes in the bar stock to match the mounting holes on the windshield wiper motor and mount the motor so both gears and gear teeth lined up (picture 2-3 looking at both sides).

Picture 4 shows the DC motor speed controller also mounted to the bar stock. The could be mounted anywhere as long as you are able to run wires from the speed controller to the wiper motor.

I found that I needed my gear to release after every large rotation. This was trial and error and I slowly used the angular grinder to grind teeth off of the larger gear (Picture 5). The created a way for the tension in the latex hose to be released at regular intervals. I'll add a video in the next step to show it in action.

Finally, I added a string which connected the threaded rod to the eye hook screw connected to the plywood on the diaphragm (picture 6)

To best view the ring of air I added a fog/smoke machine to pump fog into the trash can. I cut a 1 inch hole with a hole saw in the side of the trash can. The I cut about a foot of 1 inch PVC pipe. One end of the pipe was placed in the hole just drilled in the trash can and the other end is placed right at the front of the fog machine.

In these videos you'll see both the fog rings being shot at regular intervals and a close up of how the gears work to pull the diaphragm back and release it. Hope you enjoyed the build.