Remote Controlled Confetti Cannon

• There are a lot of ways that you can make an air cannon, but most of them will follow the same basic design. There is a large air chamber that holds the compressed air, and a valve that opens to release it. Then there is a barrel that contains the projectile. An air valve is mounted to the side of the air chamber so that you can easily attach the pump. It is also common to mount a pressure gauge on the side of the air chamber so that you can monitor the internal pressure. However, if your pump has a built-in pressure gauge, you can leave this off. Most air cannons will follow this basic design whether they are firing t-shirts, potatoes, or confetti.
• For simplicity we will start by making a basic air cannon. Then we will modify it to make it remote controlled.

Take the 2 inch diameter pipe and cut off a section that is 2–3 inches long. This will be the piece that connects the reducer fitting to the valve.

• It is important to dry fit all the parts together before you glue them together. This will you a chance to make sure that everything is fitting properly and you like the overall geometry.
• Fit the 4 inch cap on one end of the 4 inch pipe and put the reducer fitting onto the other. Then insert the short piece of 2 inch pipe into the reducer fitting. Fit on the valve. Then finally fit on the long piece of 2 inch pipe.

• Pieces of PVC pipe are fixed together in a process called solvent welding. The two pieces of PVC are essentially chemically melted and cemented together. This process should be done outside or in a very well ventilated area.
• First make sure that all the surfaces are clean and dry. Then apply a coat of purple PVC primer to all the surfaces that will be connected. Follow the instructions for the primer that you are using. You may need to apply a second coat of primer to some areas. Then apply a coat of PVC pipe cement to all surfaces that will be connected. Again, follow the instructions for your PVC cement. You may need to apply a second coat to some areas. After applying the cement, quickly stick the two parts together. Once the pieces are inserted all the way, turn them 1/4 turn. Hold the two pieces together for 30 seconds. Do this for each of the pieces that need to be connected. After assembling all the pieces, let everything sit until it is fully cured.

• The last two parts that we need to add are the air valve and the pressure gauge. The air valve lets us hook up our pump and fill the air chamber. The pressure gauge lets you know how much pressure is in the air chamber. However, if your air pump has a built-in pressure gauge you don't really need to add a second one on the cannon.
• These parts can be mounted to any point on the air tank.
• Start by drilling a small hole through the side of the PVC pipe. Then re-drill the hole with larger bits until the hole is just smaller than the fitting on the pressure gauge. You want the pressure gauge to be fit tightly in place so that it doesn't blow out when the tank is pressurized. You may need to smooth out the sides of the hole with a file. Then apply plumber's tape all around the threads of the pressure gauge. Using a wrench, screw the pressure gauge into the hole until the threads are just sticking out of the top.
• Repeat this process with air valve.

• Once the cannon is assembled, you are ready to pressurize the air chamber. Start by closing the ball valve. Hook up your air pump to the air valve.
• Slowly fill the tank. You want to do this gradually the first time because you need to carefully check for leaks. Start by pressurizing the air tank to 10 psi. Then carefully listen for leaks. Carefully open the ball valve to release the pressure.
• Fill the tank again. This time go up to 20 psi. Again, check all the joints. If everything looks good you can take it up to 30 psi. Check all the joints again. Then take it up to 40 psi.
• Let the tank sit with 40 psi for a few minutes to see if it loses pressure over time. If everything still looks good, you can be pretty confident that you made good seals everywhere.

• Now you have a basic air cannon. This will work just fine for shooting confetti (or anything else). But it has one major drawback. It uses a manual valve that needs to be opened by hand. And it isn't always convenient to have someone sitting next to the air cannon waiting to fire it off.
• We can solve this problem by adding an electric valve with a remote control. This will let you set off the confetti cannon from anywhere with the push of a button.

The easiest way to add an electric valve to the air cannon is to attach it to the base of the barrel. Take your hacksaw and cut the barrel pipe 2–3" from the ball valve.

• To connect the 2 inch pipe to the 1 inch male threads on the sprinkler valve, we need to attach some adapter fittings. I used two fittings for this. First I used a 2 inch female to 1 1/2 inch female reducer fitting to bring the diameter of the pipe down to 1 1/2 inches. Then I used a 1 1/12 inch male to 1 inch threaded female adapter fitting. Then I was able to attach the 1 inch male fittings of the valve.
• To connect the fittings, use the same procedure that you used before to connect the PVC pieces. First apply a layer of PVC primer to the connecting surfaces. Then apply PVC cement. Follow the specific directions on the bottle.

Now you need to attach the electric sprinkler valve. ​Start by wrapping the threads of the sprinkler valve with plumber's tape. Then screw on the two threaded pipe pieces that we just attached. Be sure to orient the sprinkler valve with direction of flow arrow pointing away from the air tank and towards the barrel.

• Next you can attach the sprinkler valve to the relay circuit. In this example I am using a commercial remote controlled relay. This is a single pole single throw relay. ​The circuit is powered by a 12V battery pack. It is controlled with a small handheld remote.
• Here is how I wired everything up. First the wires from the battery pack were connected to the power terminals on the relay circuit. Then a jumper wire was connected between the negative terminal and the common terminals of the relay. The sprinkler valve was connected with one wire going to the positive terminal and the other wire going to the "normally open" (NO) terminal of the relay. With this configuration, whenever the button on the remote is pressed, the terminals of the sprinkler valve will be connected the terminals of the 12V battery pack and the cannon will fire.

• ​In many situations it is not convenient to have the confetti cannon pointed in the direction where you want the confetti to be shot. In these cases you may want to add an elbow fitting to the end of the barrel. Attach this with PVC primer and cement just like you did before.
• Keep in mind that the elbow will slow down the confetti a little. But don't try to over pressurize the air tank to compensate.

• ​Now that your remote controlled confetti cannon is complete, it's time to try it out. Start by putting some confetti into the barrel. You will have to experiment with different kinds of confetti to see what works best. Smaller and lighter confetti will spread out the most. Bigger pieces of confetti will float around more. Be careful not to over-fill the barrel. If there is too much confetti jammed in there, it may clog and not shoot very far.
• Next connect the air valve on the air tank to your pump. Then pump some air into the tank (do not exceed 40 psi).
• Finally, position the cannon where you want it to fire. DO NOT POINT IT AT ANYONE! Then just pull out the remote and press the button. The cannon should fire a large burst of confetti all around. YAY!!!