Air cannons are fun, and became a part of mainstream culture with the popular Airzooka toy. Of course, cocking and firing the Airzooka gets tiring after a while, and they’re kind of a little small. This build from [1alembic] delivers on both those counts.
The result is a bigger air cannon that repeatedly fires all by itself. The cannon itself is built out of a trash can with the bottom cut out. It’s then fitted with a diaphragm made out of a heavy-duty trash bag covered in duct tape for added strength. Latex hose is then installed inside the trash can, attached to the diaphragm. Thus, the diaphragm can be pulled back, and when released, it’s pulled forward, creating a rush of air through the trash can which generates a vortex ring just like the smaller Airzooka.
The automation of the cannon is beautifully simple. A string is attached to the back of the diaphragm, and wrapped around a rod so it can be wound up. This allows a wiper motor to turn the rod via a set of gears, pulling the diaphragm back.
However, the drive gear on the wiper motor has half its teeth missing. The system is then set up so that once the diaphragm is pulled right back, the drive gear gets to the missing teeth, allowing the winder rod to spin back freely as the diaphragm shoots forward, firing the air cannon. The cycle then repeats as the drive gear re-engages the winding mechanism.
Paired with a smoke machine, the air cannon will whirr away, firing beautiful smoke rings at regular intervals until it’s switched off. It’s an elegant thing that we’d love to leave set up at a party to add some atmosphere. We’ve seen other air cannons built with some real fire-power, too. Video after the break.
Is the fog machine automated as well? i was looking for a way to trigger a fog machine via an arduino or something similar.
For this use, would you need to? You could leave it running and filling the interior of the can with fog indefinitely.
On the small (ultrasonic atomization of water) one I have, it’s possible to control to some extent by cycling power to the pump that blows air through the high fog area. You can’t really toggle the ultrasonic part well because it takes a couple of seconds to get going. But if I were going to try to control this, I’d either focus on switching the blower or on putting in a gate to cut off the output when you don’t want it.
If the shape of the opening is altered into a square or triangle, would the ring be that shape or would it ni longer work at all?
Couldnt you use an SSR to trigger a commercial fog machine or a transistor to trigger a vape coil? You just have to be careful about dry firing them as the wick only holds so many seconds of fluid (glycerol in varying concentrations).
There has to be some commercial version. Fog machines are so frequently used on stage or at a DJ booth i wouldn’t be surprised if there was a MIDI enabled one.
They use DMX (wired lighting protocol).
Higher end fog machines which are used in film/theater, like a Viper or G3000, have DMX control, whereas cheap ones you typically find at the store for halloween do not. I’ve been looking into making a handheld DMX controller which can address all our entire universes while on set and it can be done with an arduino. He could also technically build a DMX receiver with an arduino also and integrate that into a cheaper fog machine.
At least for the 400W Spirit Halloween ones, it is pretty simple. They have a NEMA C-13 connector on the back that timers/remotes plug into with a 120v Line, Neutral, and a pump motor connectors. Line goes hot when the heater is up to temp, and is internally connected to the pump motor. You can use a standard Arduino-friendly 120v relay to close the circuit between Neutral and the pump pin, activating the smoke. The pump will only run when the heater is hot, so your micro can trigger whenever without worry of cold-firing.
Standard NEMA Ground pin=smoke machine Neutral
Standard NEMA Line pin=smoke machine Line (switched)
Standard NEMA Neutral pin=smoke machine pump
That’s the kind of info I was looking for. Thanks!
This is fantastic. What a great creation!
I got the parts to build something similar but never finished, like far too many projects, although my objective was for a halloween setup. Building something like this that fires an air pulse at a fixed point on the sidewalk up to my house, in conjunction with a flash and a ghost-ish figure popping up suddenly, would be a pretty good no-contact startle.
The “no-contact” part worries me…
Have you ever build a Halloween themed yes-contact startle on the sidewalk? ;-)
Invisible/hard to see stuff hanging down that people run into, yeah, but I really like the idea of something that you can feel actually brushing against you and then you look and there’s nothing there.
Airzooka? In the 60’s and 70’s the Wham-O Air Blaster was very popular.
samer thing, stepped up an appropriate amount ;)
https://www.youtube.com/watch?v=IyAyd4WnvhU