Introduction: Awesome Water Bottle Rocket Launcher

AWBRL for short. Just the other day I was watching a mythbusters episode where they made water bottle rocket launchers for a myth. It looked like so much fun and I went ahead and bought an aquapod for $35. It was great until it ruptured under normal use and no modifications! After that, I went to my local hardware store and bought a bunch of PVC fittings and a few other things so I could make my own with better reliability. This Instructable is about how to make a reliable, high performance, water bottle rocket launcher for cheap! 
Lets make It!

Step 1: Safety

Now here is the important part. The safety information.
This is a pressure vessel. Pressure is dangerous. This bottle rocket launcher will utilize pressures up to 60psi. If you want to, you can add a safety valve but it would be easier to regulate the pressure with the source of air pressure. In my case, my portable air compressor. 
Make sure you use pressure rated PVC pipe. sch40 is recommended but I used another type rated to 260psi
As with any pressure vessel, be cautious around it at all times. 
ALL components MUST be pressure rated.
BE SAFE!
Do not use pressures over 60psi. There is no need. No increased performance at all!

Step 2: Parts

The total cost, without the cost of the schrader valve, was $25 and the Aquapod costed $35 and it offers far better peformance!
Here is the list of the parts: 
8x 10cm 15mm PVC pipes
20cm 15mm PVC pipe
3x 15mm 90 degree Elbow fittings
3x 15mm "T" fittings
15mm to 25mm coupler
4x 15mm PVC end caps
1 hose barb to threaded fitting.
1m (25 inches) of air compressor tubing
1x schrader valve (from bike tire)
2x hose clamps
10m of cord
15cm of thick wire
"O" ring to fit over the pipe

Step 3: Assemble Without Gluing

Simple. Just follow the picture and assemble it according to the picture. At the top of the 20cm piece of PVC, file a groove about 5cm down from the top. To make sure of a tight seal, use a water bottle to test. It should be reasonably tight and it should take a firm tug to pull it of. You should have a gut feeling when you get it right. Don't over file it!
Trill 5mm holes at the top of the 15mm to 25mm coupler. Put a small screwdriver through the holes once a water bottle has been "loaded". The way that the launch mechanism works is that it stops the bottle from leaving the launcher by putting a pin through the holes over the little "lip" that the bottle has. When the unit is pressurised, the pin is pulled and the rocket launches! 


Step 4: Start Gluing

Now it's time to start gluing the components just as you built them in the previous step. Simple. Make sure you glue the 15mm to 25mm coupler or it wont work very well.

Step 5: Finishing Up Construction

AFTER YOU HAVE WAITED 24 HOURS:
Drill the hole and thread in the hose barb for fitting. I used liquid nails around the threads to keep it from coming out at pressure and to ensure a good, tight seal. I used hose clamps to keep the hose barb fitting connected to the tubing and on the other end, the salvaged bike tyre valve, also with a hose clamp. 
If you want to, you can use some waterproof spray paint and paint it. That is going to be the next thing on my to do list.

Step 6: Results and Math



At 50psi, here are the results:

The rocket flew 1m in 1 frame. 
In the video, there were 30 frames a second
That resulted in 30m/s
Convert that to feet/second and it's 98.5 f/s
That equals 67 miles/hour
That then equals 108km/h and that is fast. 
If the rocket went 30m into the air, as specified as the maximum height reached by the aquapod, the rocket had a flight time of 1 second and by my timing, 3 seconds falling back down to earth
That velocity equals approximately 92 joules of energy which then equals, correct me if I'm wrong, 92w

Step 7: Finishing Up

Have fun with you'r new, high performance rocket launcher.
If I can improve this instructable in any way, let me know in the comments.
Have FUN!

Comments

author
kimwhite83 (author)2015-07-19

If I fill the bottle with water isn't if just going to fill up in the launcher base? I'm trying to make one for my son

author
KatherineG (author)2014-10-22

You didn't actually say how to launch it....Just saying. How do you launch it and where does the water come in?

author
dog digger (author)KatherineG2014-12-28

You fill up the bottle with water and the wire fork is pulled out, releasing the bottle.

author
tyustar (author)2012-11-03

What size 'O' ring did you use?

author
baalajeek (author)2012-03-21

can this launcher hold a pressure of 80psi ?

author
dog digger (author)baalajeek2012-03-22

Depends on the type of pipe you are using. If you use sch40 pipe, the bottle will explode first. The bottles can handle 150psi when they are new and 120psi after a while but don't go past 90psi

author
jacobiscool (author)2011-12-23

soooooooooooooooooooooooooooooooooooooooooooooooooo gooddddddddddddddddddddddddddddddddddddddddddddddd

author
rimar2000 (author)2011-10-09

Very good work, dog digger!

About the energy, I am not sure but think a joule is a lot of it. Maybe you can ask an enginner or physicist.

author
dog digger (author)rimar20002011-11-07

Already have! (Lewster's brother, High distinction in physics competition)

author
stantonluke (author)2011-10-16

hello, i was wondering if you had a photo of the laucher with all parts on it and what kind of air compressor tubing was used

author
ljanus (author)2011-10-16

thanks that was very helpfull

author
ljanus (author)2011-10-15

hi, i would like to know what cord is used for,the size,and what the wire is used for?

author
dog digger (author)ljanus2011-10-15

The strings length is about 30ft (10m where I live. give or take)

author
dog digger (author)ljanus2011-10-15

They are both used for the triggering system. The wire is bent into shape and used as a retainer clip that holds the bottle in place. In the next step I had the small screwdriver through two of the four holes drilled in the 25mm to 15mm coupler. That is where the clip inserts into and the string is used to pull the clip out from a distance to launch the rocket

author
ljanus (author)2011-10-15

need to know as soon as possible!

author
lewster (author)2011-10-09

92 joules per second, or total?... coz 1 Joule per second equals 1 Watt.......Don't argue with Tom, top of Yr 11 Physics...

author
dog digger (author)lewster2011-10-10

the propelled flight was one second so, the answer to the question is Both!

author
lewster (author)2011-10-09

Jokes, it's really cool!

author
lewster (author)2011-10-09

yeah i know how to make it better..... It could be my air cannon!
https://www.instructables.com/id/Cheap-Powerful-Air-Cannon/

About This Instructable

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Bio: I like electricity I like electronics I like.... SO MANY THINGS music, subwoofers, computers, woodwork and metalwork, Just look at my interests! I love music ... More »
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