How to: Handheld Water Rocket Launcher

A simple tutorial on how to make a handheld water rocket launcher. Have Fun!

Step 1: Materials

Materials:
- 5 Feet (0.5" PVC Pipe)
- 1 Foot (1.5" PVC Pipe)*
- 1 (0.5" PVC End Cap)
- 1 (Small Bottle- PVC Glue)
- 1 (Waterproof Silicone Caulk)*
- 1 ( 1.1/8" OD - 23/32" ID Rubber Grommet)
- 1 (#2 Rubber Stopper)
- 1 (Roll of Duct/Duck Tape)
- 10 (8" Zip Ties)
- 1 (Ball Inflation Needle)
- (Water, Soda, 2-Liter Bottles)

Tools:
(Drill)
(1/16" Drill Bit)
(3/8" Drill Bit)
(PVC Cutter)
(Exacto Knife)
(Bicycle Pump)
(Permanent Marker)
(Mallet)
(Lighter-Candle)*

*Among everything needed I did include revised materials that I found we would need after testing. These materials were used to make a better launcher than original.

Step 2: Release Mechanism

Release Mechanism: Used to lock a bottle onto the launcher while being injected with air.

1. Insert the (0.5" PVC Pipe) into a soda or 500ml water bottle leaving about a 0.50" clearance from the bottom. Mark the line where the mouth of the bottle is on the pipe with a (Permanent Marker). This is where we situate the mechanism. After the line, leave about a 1.5' extension of (0.5" PVC Pipe) with the (Pipe Cutter).

2. Remove the bottle and slide the ( 1.1/8" OD - 23/32" ID Rubber Grommet) onto the pipe at the line we marked. This will serve as the "seal".

*Revised: During the testing, I realized that our seal wasn't sufficient so by using a (Lighter-Candle), heat the (0.5" PVC Pipe) at the line and push the pipe together to create a bulge. You may also leave the (1.1/8" OD - 23/32" ID Rubber Grommet) in place after heating and cool down.

3. Grab a (Zip Tie) and place the bottle onto the 0.5" pipe. Line the locking block of the zip tie with the lip of the bottle. Make sure that you get close contact. Keep the zip tie straight and mark a point with the (Permanent Marker) where the grommet meets the zip tie on the longer side of the pipe.

4. Rip about a 6" piece of the (Duct/Duck Tape) and lay it down on a flat surface. Lay the zip tie on the tape at the line we marked on the zip tie. Using about 5 more zip ties, lay them on the tape at the same level with the first marked zip tie. Make sure that when you wrap the tape on the pipe, the zip ties don't overlap. To finish, and secure the zip ties, use another 6" strip of tape and lay that on zip ties. Wrap the zip tie apparatus onto the pipe and secure with duct tape onto the pipe. Tape the ends of the zip tie onto the pipe as well and make sure to push down and keep tight.

5. Cut about a 3-4" piece of the (1.5" PVC Pipe) with the (Pipe Cutter). Place the ring onto the 0.5" pipe over the zip ties. This will lock the zip ties onto the bottle.

Step 3: Air Injection Device

Air Injection Device: used to fill the water rocket with air and keep it tight.

1. At the end of the 0.5" pipe, use the (#2 Rubber Stopper) and shove it into the end of the pipe. As you will notice, it isn't a perfect fit so we have to shave it down using the (Exacto Knife) and force it in with the (Mallet). The tighter fit, the better.

2. Using the (0.5" End Cap), drill a hole in the center with the (3/8" Drill Bit). You may need to shave the sides out to fit the wide lest part of the (Ball Inflation Needle).

3. Using the (PVC Glue), Secure the end cap onto the end of the 0.5" pipe over the rubber stopper. With the (1/16" Drill Bit), drill into the center of the stopper and fit the needle into the hole.

4.

Revision: Originally, that was it for the air device but during testing, the device was too leaky. Leave the widest part of the needle out of the end cap piece and fill the area between the end cap and stopper with the (Silicone Caulk). Once dried, you may push the needle all the way to the surface of the end cap/caulk.

Step 4: Usage

Usage: You have now completed this project and are happy to try it out.

1. Fill the bottle about halfway with water. I encourage you to test how much water to use to achieve the best performance.

2. Fit the bottle onto the launcher and lock into place with the zip ties and sliding ring. Push up to cover the zip ties and lock them onto the bottle's lip.

3. Attach the (Bicycle Pump) onto the needle and have a friend pump the air into the launcher and bottle.

4. Make sure to hold the launcher securely and when you are ready to launch, pull back on the ring, let the bottle release from the zip ties and get a little wet.

5. Repeat.

Step 5: Troubles

Troubles: I do admit that this isn't the best launcher but is mighty easy to make.

- I had to include revisions because I found that they have better performance. Albeit, not as great as perfect.

- I have found that the needle tends to bend and break off the air injection device when the launcher isn't held securely during launch because the launcher kicks back. Because of this, I do these to hold the pump pipe onto the launcher with one hand and have the ring in the other.

- I enjoy using the zip tie device to lock the bottle onto the launcher but sometimes, they may need to be readjusting for a tighter fit.

- This is my first Instructable and I do hope you will enjoy making this launcher. Although I did fail to make it (Instructable) when I made the actual launcher so I can't give pictures of it in use. It is winter and we did lose it somewhere. I openly accept adjustments and am open to trying new things on the launcher.

-Thank You :-)