This is a compressed air rocket launcher. It uses common PVC pipes and fittings anyone can get their hands on.
It can launch anything from Nerf darts to Homemade rockets. I got all the parts from a local Lowes for under
$30. A normal bike pump can pressurize it, but you can use an air compressor to do it faster. The normal pressure I use is 45-75 PSI. No prior experience with piping is required. Here is a list of parts:
3x 1/2 inch ball valves
4ft of 1 inch diameter PVC pipe
1x Automotive Tire Valve
3x 1 inch diameter PVC Pipe Caps
2x 1 inch by 1 inch by 1/2 inch PVC Pipe 3-way Tee
1x Bottle of PVC Pipe Glue
1x Bottle of PVC Pipe Primer
1x 1/2 inch by 1/2 inch by 1/2 inch PVC 3-way Tee
4ft of 1/2 inch diameter PVC pipe
1x Bottle of Super Glue (any brand works)
1x 1/2 inch PVC pipe Cap
1x 1/2 inch to 1 inch PVC elbow bend
Here is what all the parts do.
The four feet of 1 inch pipe will be cut into four equal pieces and connect to the 3 way 1 inch tees and serve as pressure tanks on both sides. Making four tanks each 1 foot long. There is a diagram in the beginning showing how these pressure tanks connect. (Figure 1)
The two 1/2 inch pipes coming from the 1 inch to 1/2 inch tees will connect in the middle via a 1/2 inch tee.
The 1/2 inch tee will connect to the launch tube with a ball valve to control when the rocket launches.
Figure 2 shows how this works.
Also, there is a second shot valve. If you close this valve after it is pressurized, you can have two shots since there is stored pressure separate from the rest of the of the system. Of course, it will not be as powerful as only firing once. Figure 2 also shows where this valve is.
Did you notice that I only included 3x 1 inch PVC pipe caps in the list when there are 4 pressure tanks?
I did this because the 1/2 inch to 1 inch elbow goes there. The 1 inch end connects to one of the pressure tank ends, and the 1/2 inch end connects to the third ball valve and the 1/2 inch PVC pipe cap. Your probably wondering "What's the use of having a ball valve connect directly to a cap?". Well, the 1/2 inch cap is going to have a hole drilled in it, and in that hole we are going to super glue the automotive tire valve on. The tire valve is going to serve as an input for air from an air compressor or bike pump. This is how we are going to pressurize the system. Figure 3 shows how this works.
Now that that's over, let's get started!!!!
Step 1: Cutting All the Pipe
Let's get the hard stuff out of the way and cut the pipe.
To cut the pipe, use a standard hacksaw.
First, cut the 4ft of 1 inch pipe into 4 1ft long pieces. Set them aside for now
Second, cut the 4ft of 1/2 inch pipe into one piece measuring 1ft long, 4 pieces each measuring 4in long, and 2 pieces each measuring 6 inches long.
The 4 pieces of 1 inch pipe will become the pressure tanks.
The 1ft long piece of 1/2 inch pipe is the barrel.
The 6 pieces of 1/2 inch pipe measuring 4 inches long connect the air supply to the pressure tanks, and the
pressure tanks to the barrel.
Step 2: Sealing the Pipes Together
Now that you've done the hard part, on to the second hard part.
Pipe sealing is dangerous business. The sealant itself is a neurotoxin, so masks are mandatory. Also, it will stick to your hands like super glue, so gloves are also mandatory. It is also highly flammable and has toxic fumes.
Use in a well ventilated area. Disclaimer: I am not responsible for any brain damage or property damage due to using pipe sealant.
Now that you have appropriate safety precautions, on to the sealing. First, put a coat of PVC primer on to the end of one pressure tank and inside one of the 1 inch caps. Then, quickly put a coat of sealant on top of the primer.
Press the pieces firmly together and let them dry for about 24 hours. Repeat this process for all of the pressure tanks. The pressure tanks should look like Figure 4 after sealed.
The second seal is sealing two pressure tanks to the 1inch by 1inch by 1/2 inch tee.
Take one of your pressure tanks and coat the other side with primer, and do the same for 1 of the 1 inch ends of the tee. Then coat it with sealant and press the two pieces together. Repeat this with the other one inch end of the tee. It should look like Figure 5. Repeat this process for the other 1 inch by 1 inch by 1/2 inch tee and pressure tanks.
On to seal 3.
Take one of your 6 inch long pieces of 1/2 inch PVC pipe, then prime and seal it to the 1/2 inch end of the 1 inch by 1 inch by 1/2 inch tee. Repeat for the other tee and 1/2 inch pipe. It should look like figure 6.
Seal 4 is sealing a ball valve to one of the 1/2 inch pieces of PVC pipe coming from one of the tees. This is your second shot valve. DO NOT do this for the other side!
It should look like figure 7.
Seal 5 is very simple. Attach one of your 4 inch long 1/2 inch pieces of pipe to the other end of the ball valve.
Seal 6 is a little more complex. Attach the pipe on the other end of the ball valve to the 1/2 inch by 1/2 inch by 1/2 inch tee.(make sure the tee is facing up!!)Then attach the other pressure tank unit to the other end of the tee.
It should look like figure 8.
Seal 7 is very simple. Attach the second piece of 4 inch 1/2 inch pipe to the top of the center tee.
This should also look like figure eight.
Seal eight it one of the last seals, attach the second ball valve to the top of the pipe on the center tee.
On top of that, Push your 1 foot long piece of pipe on. Do not glue this.
Figure 9 is the completed launch frame. All that is left is the air supply.
Step 3: Air Supply
The next step is drilling a hole in your 1/2 inch cap. It should be about 1/4 in diameter. Next, take your automotive tire valve and stuff it through the hole in the cap you just drilled. Make sure it fits tightly, or air will leak out.
Once you are sure it is tight, apply super glue on the outside of the cap and around the tire valve. Using sealant and primer, glue this cap to the third piece of 4 inch long 1/2 inch pipe. On the end of that piece of pipe, glue the the third and final valve, the air seal valve. On the end of that valve, glue the final piece of 4 inch long 1/2 inch PVC pipe. Seal the 1 inch to 1/2 inch elbow bend on to the open end of one of the pressure tanks.Then, seal the 1/2 inch end on to the pipe coming from the valve. Your Rocket launcher is Done!!! Remember to let all connections set before use. Figure 10 shows the completed air supply. Figure 11 shows the completed launcher.
When you want to launch this, connect your air pump and pressurize to 30psi at first. You can slowly make your way up to 75+ psi. Launching paper and tape rockets is fun, and nerf darts fit perfectly in the 1/2in barrel. Once your ready with a projectile, aim it at ANYTHING BUT ANIMALS, PEOPLE, OR ANYTHING YOU DON'T WANT ANNOYED OR DESTROYED. I AN NOT LIABLE FOR ANYTHING/ANYONE THAT IS INJURED WHILE USING THIS.
Please vote for me in the Epilog VI contest!