It's fun to make, and a huge hit at birthday parties!
Step 1: Watch the Video!
WARNING: This project uses compressed air as the medium for projecting candy, and thereby poses various safety risks. This project should not be attempted without adult supervision and adequate training. Misuse, or careless use, of tools or projects may result in serious injury or death. Use of this video content is at your own risk.
Step 2: What Is a Candy Cannon?
It uses an electrically activated in-line sprinkler valve, rated at 150 PSI, as the trigger mechanism to release compressed air through the barrel.
Just charge the system up to around 150PSI, and press the detonator button to make it fire!
I built this one for my son's 3rd birthday party to propel a payload of candy to an altitude of around 100 feet, at which point the candy begins to spread out into a giant could of sugary treats, and drop back down, making it rain candy!
You can probably imagine the excitement of the kids with their little treat bags running all around the yard on a candy treasure hunt!
Step 3: Materials You'll Need
Without listing individual parts, I hope the picture gives enough of an idea for your to duplicate the project.
I used 2" schedule 40 PVC pipe for the air tanks, and 1" schedule 40 PVC pipe for everything else. You should be able to find all these materials at a home improvement store, or sprinkler supply company.
Aside from those, you'll probably want a 3/4" manual ball valve, and some other 3/4" fittings that will allow you to join it to the frame.
You'll also need a 1" FIPT in-line sprinkler valve.
To make the air tanks, cut two sections of the 2" PVC pipes 12" long.
Cut your 1" pipe to custom lengths (Anywhere from 2"-4").
Feel free to use some creativity to modify the system, but basically it will look like this when the pieces are dry-fit together.
The system is designed to accept compressed air through a pneumatic adaptor we'll add to the cap near the manual ball valve. This valve allows you to close off the system, and the cannon will stay pressurized even if you disconnect from your source of compressed air.
A 9v battery will be used to activate the sprinkler valve. The valve is actually rated at 24 volts, but I've found a single 9v seems to work ok for this purpose.
If you're happy with how the pieces fit together, then it's time to make it permanent by cementing it together!
By the way, did you notice these parts strongly resemble the parts I used in my Rocket Rifle project?
Step 4: Make It Perminant
Some brands of PVC cement are self priming. An example would be something like "Christy's - Red Hot Blue Glue".
Make sure to read the instructions carefully on both the can of primer and can of PVC cement. There are dangers associated with each, and attention to detail is required in order to get a good connection that can withstand 150PSI. Remember, this system is going to be containing a dangerous amount of pressure, so you'll want to do it right the first time!
Prime all the parts that will be in contact, and when they are dry, cement it up as instructed on the can.
Step 5: Cannon Wads
I cut a 1/4" off the top of a small 3oz plastic cup, and cut the bottom part off a regular sized up. Then I fit them together to make this little container.
This design had impressive structural integrity, which meant it could withstand the blasts of high air pressure, and be used multiple times before having to make a new one.
The diameter of the wad is about as perfect as I could find for the inside of the 2" candy barrel.
You may also notice a coil of wire in the background of the picture. This is doorbell wire that connects the valve to the detonator button. I wrapped the wire around a length of the 1" pipe to form the coil.
Step 6: Finishing Touches
The pneumatic adapter is where an air hose can be connected to charge it up, and the manual ball-valve gives the option of closing off the system. This meant the system could maintain pressure even while the air hose was disconnected, thus making it portable.
If you don't have an air compressor, then instead of this pneumatic adaptor, you could change it out with a valve stem to be used with a bike pump.
Step 7: Making It Work!
Individually wrapped candies are a better choice when actually using for a party, however these jelly candies were mainly for testing the ballistics of small dense candies.
When the detonator button is pressed, the sprinkler valve opens and blasts the cannon wad upwards. The wad pushes all the candy out with a considerable force.
In this case, 3 lbs of candy was launched up around 100 feet in the air!
This has become a hit at birthday parties, and we are making it a tradition to do a candy launch at each of our kids' birthdays. And, of course, the birthday boy is the one who gets to push the detonator button!
Haven't see the video yet? You can still see it here!
If you like this project perhaps you'll like some of my others. Check them out at www.thekingofrandom.com