Instructables
Picture of water rocket launcher
this is an instructable working with rockets. water rockets in particular . this launcher can send 2 liter bottles over 500 ft. in the air .use at your own risk. it is from http://sciencetoymaker.org/waterRocket/index.htm so i give all the credit to them
 
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Step 1: Materials

1 10 foot piece of 1/2 inch, schedule 40, PVC (plastic) pipe. You might be able to find this in the plumbing section of a building center/hardware store, or in the form of conduit in the electrical area. Usually the conduit pipe is gray in color instead of white.The pipe size is printed on the pipe. If you actually measured the pipe, you would find the outside is about 21mm (almost 7/8"), and even the inside is 15mm (9/16"). Choose by what is printed on the pipe, not by actual measurements. The "schedule 40" refers to the thickness of the pipe, and rest assured that schedule 40 is the most common, easiest to find kind. See picture below.

1 piece of PVC 1 1/2" (one and one half inch), schedule 40 pipe. You only need 2 inches of it, but some building centers only sell it in 10 foot lengths (even a 10' long piece is only a few dollars). You might be able to find a sympathetic plumber or home handyman who can give you a couple of inches. 2 PVC 90 degree elbows for the 1/2" pipe.
1 end cap for the 1/2" pipe above.
1 small can of PVC pipe cement (or borrow some).
1 package of 8" (or close to it) general purpose ties (also called cable ties). These will be in the electrical wiring area of the building center.
1 hose clamp. The size is important. I get hose clamps with a range from 11mm to 23 mm (a little less than 1/2" to a little less than an inch). The hose clamp must be a little bigger than the pipe because that's what holds the all purpose ties securely to the pipe. Better to have the hose clamp a little too big than a little too small.
1 tire stem. This is the one thing you are not likely to find at a building center or hardware store. However, it is easy to find at any automotive parts store. Tire repair shops often throw them away. The inner core of the tire stem does not have to work, or even be there. If you tell the person at the tire repair shop they might give you some free.
A half inch (1/2", 13mm) diameter drill bit, a quarter inch (6 or 7mm) diameter drill bit, and drill. There are only two holes to drill, so if you don't have a drill find a neighbor who does. You will only take a minute of their time. A drill press is even better.


TheHobbyGuy made it!2 months ago

We made this launcher for our LED Bottle Rocket Fireworks. One change we made was instead of heating the pipe we filed a grove and used a O-ring. Also, we made a square base. Very nice instructable, thank you. Thank you.

DSC05440.jpg
Skymeat3 years ago
I made this yesterday - Mostly I just copied the release mechanism, but here's a couple things that made it easier for me:

The bulge: My bottles fit snugly on the pvc, so the bulge is very slight, the pottles fit very snugly.

The Valve: I used a 1/8 npt Schrader valve, It just threaded into the end cap, and then I epoxied it for good measure.

Also I made the valve point up with another elbow, which prevented water from getting in the pump.

I'm easily filling regulate bottles to 100psi.

Thanks,
Skymeat
El Diablo974 years ago
Instead of heating the pvc pipe up, use a file and make a groove around the pipe as evenly as possible. Then wrap some duct tape, teflon tape, or electrical tape around and along the groove. It's not a good idea to heat up pvc pipe for three reasons: 1. PVC is called Poly Vinyl Chloride. 2. If it catches fire, it burning will release chlorine gas. 3. If the melted plastic drops on you, it burns like heck (I learned this one the hard way).!
I'm sorry but your first point was just acknowledging that PVC stands for Poly Vinyl Chloride. Your second point is untrue. Burning PVC does not release chlorine gas, that's just asinine. Chlorine only naturally exists in bonds. When PVC burns the chlorine creates airborne dioxins, which are no more harmful than airborne table salt, which contains chlorine as well. Your last point, while correct, is off base. Bending PVC pipe requires heating it until soft, just like a metal. If you heat it to the point where you are dripping the PVC, which in its usual state is a polymer, so should resist dripping anyway, you have done something horribly wrong. Lastly, by filing the PVC pipe you are weakening it much more so than bulging it, in a pressure sensitive environment this could lead to shattering of the PVC, which is a much more real and hazardous situation than the points you make in your post.
apun_1214 years ago
thanks i will try it
apun_1214 years ago
i did as you said and also i saw it on youtube...
the launcher was awesome !

i have a little problem in the bulging area using the candle.

i did the bulge , but that bulge was not proper !

i used a insulation tape so that it would stand  , still i have the leaking problem .

sugest a way to stop the leaking from the bottle .

thanks
apun_121
Well, could you heat up the bottle and squeeze the neck/part with threads so that it would be smaller? Or you can find a piece of PVC that fits just right around 1/2" PVC and cut the neck of the bottle off and glue the piece onto it? Just an idea...
Just built an air cannon. there has to be a to mod it to do the rockets also.
ilikebombs6 years ago
hey I am considering trying to make a water bottle rocket bazooka and I need a good release mechanism any other ideas for one? I looked at pitsco and found they have one I could buy that could screw of the bas its one but its $40 not assembled.
HEARING PROTECTION!!
do not test this device on your shoulder without hearing protection..
This option might be a useful one, it won a contest so it should be good Tell us about it when you're done!

: )
garden hase attachment will find website i found the idea of
robert (author)  ilikebombs6 years ago
what are your requirements for it? on this on you have to have it at a slight angle for it to seal.you could probaly make a cool trigger design for it ...i will make a video and post it when the weather gets warmer>
thanks, unofrtunatly it may be postponed due to certain cercumstances, but yes i was hoping for a good trigger design. Right now i am working on my first instructable, although it is not yet complete due to money issues, and may not be for a month or two unfortunetly.
 I know this is an old instructable, but I just built one.. it is far in advance of some of the other launchers I found here, but I found an improvement to this step.. after such a graceful design, I was disappointed when I had to create friction using duct tape as described in this step.. I chose to create a four-ziptie contraption at the base of the trigger-pipe, notched the pipe and pulled the ziptie's slack into the notches, melting them in place.. the mod allows the friction to be adjusted so that it won't fall down, but is still loose enough that  my launcher does not fall over when the string is pulled, taa daa!

heathbar644 years ago
 Your latch mechanism is truly ingenious. 
Blo0dZsTa5 years ago
wow very cool hey if u want to see how to make an easy water rocket check out my instrictable!
It really isn't very nice to advertise your instructables inside other instructables without the authors consent ;)
eyebot1175 years ago
Could this technology be used in a barrel and shoot water balloon-tipped rockets horizontally (not at people)? I think I might be able to do it by layering balloons in the bottle to create thrust, but is there an easier way?
EvilJack5 years ago
I watched the same show and came up with a similar design. I don't like the match and melt approach, so I used a 1/2 pvc coupler at the point where you would expand the pvc pipe. I added a piece of rubber where the bottle and the pvc coupler meet to get a tighter seal. I don't really like the zip-tie coupler. When we pressurize the bottle, the zip-ties and hose clamp tend to slip. I need to re-do my zip-tie / hose-clamp setup. I'm going to try a design where everything is the same, but I put a ball joint control valve in-line and use that to release the air flow... I am thinking that this will give less pressure since the water won't be pressurized..... My kids really enjoy this one...
Tommyhzy5 years ago
Hey, guys, check out the Youtube version of this, it's updated and newer. I built one, decorated it and the bottle, and it flies GREAT! all my friends are interested, but the task is too daunting to complete by themselves, so they just borrow mine. I'm currently working on my own design using this trigger system.
Painterguy5 years ago
Great job, Robert!
I was catching up on my episodes of Ask This Old House
and saw, I think, the exact same design. Is that you by chance?
same same.. saw that episode few days ago...
starwing1235 years ago
If you modify it, you can put water balloons on the rocket and make it look like a RPG7, it would be a water balloon launcher
Shagglepuff6 years ago
I built a bottle rocket launcher that's alot simpler than this. I'll try to post it soon
sofaking6 years ago
I made this and it looks awesome but it keeps raining so I can't launch it.
dj whatever6 years ago
mythbusters idea??? (straws)
nice instructable although!!
teach676 years ago
I made a similar launcher. Mine is different in that I made the pvc that goes up into the bottle shorter so we can launch smaller bottles or rockets that have been smashed from rough landings. Also we use a compressor so we can launch 100 rockets in less than a hour. Kids love that they get wet launching the rockets. Our trigger is a piece of pvc that slides over the body of the launcher connected to four 4 foot strings that connects to the pvc that compresses the cable ties. Keeps the rocket at least five feet above the students heads.
schmidtty6 years ago
your trigger and lock system is pure genious
Taz946 years ago
sweet
receiver5456 years ago
instead of your confusing trigger that could shoot off any time try using a water hose quick release holds high pressure and fits on to 3/4 in. PVC.
if you sand down the threads and use Teflon tape!!
and the other end is like a rocket spout so it shoots a small fast stream of water out the back end, and the up sides to that is that it fits perfect to a 2 liters threads! that is the best way to do it !! '
robert (author)  receiver5456 years ago
no. you pull a string and it fires. also this one is better because it has more airfkow, which makes it fky higher
i beg to differ i make a cannon that did the same thing you did with your launcher and it didnt go jack as far as mine did well it dont matter i might hav accidently screwed up one of the steps!
rimar20006 years ago
Very good!
Very Cool!