Paper and Soda Bottle Rocket Launcher

by davemcp

72K10038

Intro: Paper and Soda Bottle Rocket Launcher

This is a simple and inexpensive alternative to estes rockets. I wanted to do something to allow my kids to play with model rockets, my concerns were that estes rocket motors are highly flamable and the kids could only play with them if my wife or I were around. Another factor was the cost. The smallest Estes motors run about $5 for 3 motors, not a lot of fun with a yard full of kids.

We made a paper rocket launcher that used compressed air. This meant that rockets were cheap (1 piece of paper for the body and part of a piece for the fins) and safe. After several weeks of playing with the paper rockets one of the kids grabbed a soda bottle and stuck it on the launch tube and the rest is history. For hot summer fun soda bottles and water make this a real blast of wet wild fun.

STEP 1: The Parts List

1 - 1" inline sprinkler valve
2 - 2" PVC pipe 18" long
1 - 1/2" PVC pipe 18" long
4 - 1" PVC Pipe 2" long
2 - 2" PVC Elbow
2 - 2"X1" PVC reducer
1 - 1" PVC T
2 - 1" slip to 1" Male Thread PVC fitting
1 - 1/2" slip to 1/2" male thread PVC fitting
PVC Glue

Lauch handle parts list
1 - 1.5" PVC pipe 4" long
2 - 1.5" PVC Cap
6' 2 conductor 18 or 20 AWG wire
1 - Momentary switch
1 - 9v battery connector
1 - 9v battery

Total cost around $40

STEP 2: Time to Start Gluing

Glue the fixed parts together using pvc glue

STEP 3: Add the Valve (no Glue Here)

These parts are not glued. They are just finger tight, so if something breaks later on you can fix it easily. It also allows some flexibility to aim the rockets.

I predrilled the hole for the fitting just smaller that the threaded fitting then used a wrench to tighten.

STEP 4: Launch Handle

I did not build my launch handle. I bought it premade at http://www.itsablast.com for around $15 but I will show you how to make one.

drill a hole in one cap the appropriate size for your momentary contact switch button. Insert switch and solder the negative (black) wire to the switch. Solder the negative lead of your 9v battery clip to the other terminal of your momentary switch. Connect the positive wire from the 9v battery clip to your positive wire using a small wire nut. Feed the wire through the 1.5" pvc pipe and slip the cap on without glue.
Drill a small 3/16" hole into the other cap. Tie a knot in the wire to keep it from pulling through the hole and feed it through so that the long wire tail is outside the launch handle when assembled. Install battery and slip the bottom cap onto your launch handle. Using wire nuts attache the launch wire to the sprinkler valve solenoid.

STEP 5: Have Fun

Give the glued parts about an hour to dry and then hook it up. I use 30-40 psi only but it may work at higher preasures.

I am not responsible if you jack this up to 200 psi and loose a hand or eye to flying pieces of PVC.

Be safe and Have a blast.

Complete launchers and parts can be purchased at http://www.itsablast.com

34 Comments

DanTDM 10 years ago

Use a QEV and steel pipe.

DanTDM 10 years ago

Never use PVC pipe. Use galvanized or copper pipe (black iron works too) and use a manual gas ball valve with a handle.

bracketracer 11 years ago

Love this project! I made a slight change to the paper rockets. I used 8 1/2 x 11 card stock for the body and 3/16 foam board for the fins. I cut it with a standard box knife and attached the fins with wood glue. For the nose cone I took 1" poplar dowel rod cut to 2 1/2" long and turned it on a wood lathe. I used the wood glue to attach the nose cone also. The rockets balance nicely and weigh 1 oz total. We shot the first one a dozen times so far, it flies great and lands undamaged. Lands straight on it's nose every time, as you can see from the grass stains! I made a little fixture out of the leftover launch tube to help glue the fins on straight. I misread the instructions and used plastic wrap (food wrap) on the tube I use to roll the rocket bodies. About 6 turns worked great! I used 3" PVC for the reservoir, but only because I had some left over from a previous project. I added a gauge and cut a groove for an o-ring so we can launch water bottles too. On mine, I had to put two 9v batteries in series because one 9v would only work up to 25 psi. With two, it operates quite a bit higher. We made a clinometer also so we could estimate the maximum altitude.

MonkeyBoy3217 13 years ago

I bult this instructable awhile ago. Recently the piece from the sprinkler valve to the holding tanks gave way while it was pressurized. I think the cause of this is because that same piece is really long, so whenever it launches it moves up and down alot. Thought I'd let you know. MonkeyBoy

JimKelleher 13 years ago

I built a similar launcher for paper rockets. We use 8.5 x 11 copy paper for the rocket body and nosecone and card stock for the fins. We stuff the nosecone with a half of a paper napkin so it holds up better to the landings. I've tested launches from 10 psi to 70 psi in 10 lb increments and found 30 to 40 psi to be the best. My launch tubes have threaded fittings on them so I can change them out easily. I have 1/2" and 3/4" X 18" and 38" versions. Best performance seems to come with 1/2" X 11" body tubes at 30 to 40 psi. A rocket made with 36" wrapping paper launched at 40 psi makes an impressive sight going up but crumples when it lands. Also, I use 3@9V batteries in the launcher and after hundreds of launches the original set is still going strong. One more thing, I used a compressor during testing, but a bicycle pump when the kids are building and launching. Gives them some feedback when they are supplying the 'energy' for the flight.

ghostWolf59 15 years ago

I have just built this according to your instructions - Unfortunately I don't have a compressor so I had to rely on a bike pump - and as such I am buggered if I can get enough pressure to make the bottle fly high. Seem that the pressure not is released all in one hit - feels almost like the valve could be to blame. I have used a off the shelf mainstream valve suitable for retic. Any suggestions - or is it that I simply cant provide enough pressure using a bike pump ? Difficult to say how much pressure I have, but its gets really heavy to pump after a while so I guess the pressure have built up. I have also made sure the valve is aimed in the correct directions as well as made sure there is no leaks. Would appreciate any suggestions - Dont have the $$$ to buy a compressor though

davemcp 13 years ago


We have had other people use this design with the bike pump and it has worked fine in it's current configuration.  You could use larger diameter pipe for the accumulator legs or jus make them longer if you wish.  If your valve seems to be opening slow or incomplettely you could add a second nine volt in series with the one on the plans giving you 18v to open the valve.  This should give you a good solid voltage to open the valves.  Most sprikler systems work on 24v so this could really help.

Dave

heathbar64 13 years ago

 If I'm understanding this thing correctly, the bigger pipe is serving as an air reservoir of sorts, so that when the valve is opened the air is released all at once into the launch tube. I'm thinking that with a hand pump, the volume of the reservoir is not enough. with the compressor, it's tanks supply the air with plenty of volume. You could add an additional tank to correct it. Maybe you could connect a hose from your spare tire to serve as additional air storage on the cheap.

davemcp 14 years ago

Another suggestion I have received is to add a second 9v battery making the valve open better. Dave

BigMac96 14 years ago

I've seen both used before. You get more exercise from the bike pump :-) I'm just never sure about the psi. Maybe I can find a meter that I can put between my pump and the luncher.

davemcp 15 years ago

You can use a bike pump, My guess is that the valve is the problem. You may want to open it up to make sure that there are no obstructions. You could test it by taking it over to a tire store/garage and borrowing their compressor to test. Dave

DJDeegee 14 years ago

Does every Bottle rocket launcher use sprinkler parts. I just cant seem to find a single easy rocket launcer without all the awesome proffesional stuff..

TOCO 14 years ago

try this launcher. I am building it tomorrow. I built a rough version today.

archimeech 14 years ago

Thanks for the Instructable, nice job.  I'm curious about what your paper rockets looked like?  Any shots of some of the simpler ones the kids made, and what was the range at 30-40 psi?

davemcp 14 years ago

We just use normal 8.5" X 11" paper or construction paper to build our rockets.  if you put a piece of shrink wrap tubing over a piece of 1/2" PVC it makes a great form to ROLL your rockets.  There is also a site where you can buy them premade or buy nose cones or whatever you need.  It is not my website and I am in no way affiliated with the owner of the site.
Http://www.itsablast.com
and yes the rockets take 30-40 psi without too much problem.  if you roll your rockets to 8.5" length instead of the 11" length we have had some take 60 psi or so.  They really go at that pressure.  But remember increased pressure means increased risk.  I know someone will put the presure way up there and I am not responsible for damage or injury.  I only recommend using 30-40 psi.  Anything higher you do at your own risk.

Dave

davemcp 14 years ago

I have not had any problems with using a single 9v battery but you could try using 2 in series connet the + terminal of the first battery to one lead of the sprinkler valve, connect the - lead to the + lead of the second battery and the - lead of the second battery to the other lead to the sprinkler valve. If this still doesn't work pull the solenoid on the sprinkler valve and make sure that it it pulling in the plunger when you hit the button.

thedolb 14 years ago

a 9 volt battery wont trigger the valve. am i doing something wrong

carl87gt 14 years ago

Here's mine (picture is before I glued it all up). I actually added a another bend upward right before the sprinkler valve. I have a screw on end cap with the tire valve on it. This is so I can replace the end cap to one with a compressor when a compressor is available. My son, neighborhood kids, nieces, and nephews have been having a blast with this!

rock climber 15 years ago

Wouldn't the wires get wet when the water came out of the bottle
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