Category: Air Rocket

Air Rocket and Launcher Variations

Some innovative people came up with cool variations. If you send pictures or video of yours, I will post here.

Erik Herman, Xraise Cornell

COMPRESSED AIR

Kids have a way of stomping on the end, breaking the bottle. Wouldn't it be great if we could pump up air resivior instead of stomping? My freind and collaborator Erik Herman, who does science outreach at Cornel University, came up with a brilliant mechanism.

From a safety point of view, it would be very difficult to accidentally launch it. The higher the pressure, the harder you have to push to launch it. From an education standpoint, it’s so visible and available for kids to figure out how it works. From an economic standpoint, ingenuity triumphed over money!

Illya Quandt of Nevada

Illya Quandt of Nevada developed an air rocket variation which is an alternative to the short, lashed-on legs that keep the rocket pointed into the sky. He makes legs from plastic pipe that is one size larger than the 1/2" pipe that actually conveys the air from the bottle to the rocket. Here is a picture, and if you want to know more about it, go to the bottom of this page. I have not tried it yet, but if it works for me I might rewrite the directions.

Guy Migneron of Canada

A launcher and rocket ready to fly, by Guy Migneron of Canada. As an alternative to white plumbing pipe Guy used 1/2" PVC electrical "conduit" pipe, which is usully gray and usually used to contain electrical wiring. As you can see from the picture above, an added bonus is that the 90 degree elbow has a more gentle curve. This probably results in less friction as the air rushes through the tube. You find it in the electrical section rather than the plumbing section.

Phil Weglarz

Phil Weglarz sent in a clever rocket variation with a parachute. He says, "Adding an inverted bottle cap to the tip allows the rocket to carry a payload with parachute, which deploys on its own on the way down. I used the standard army guy with chute and glued him onto a piece of cork that fits in the bottle cap. (here's a close-up of our "pilot" on the launch pad) "I have also made parachutes that attach directly to the rocket.(1:03 or so, among other science exhibits).
We had to dumb-down the launchers because the rockets were hitting the gym ceiling so hard that I was afraid they would make holes!.

More about Illya Quandt's Rocket Launcher Leg Design

Here is the picture: And here is a closer view of that picture. Notice the 1/2" pipe actually goes through the 3/4" cross intact. There is no need to block off the air from escaping.And here is just the legs.

And here is Illya's explanation:

Thank you so much for this great site. I just wanted to share with you some modifications I made to your air rocket plans. For the stand, instead of lashing 2 one foot pieces of 1/2″ PVC to the long piece of tubing, I used a 3/4″ cross with 2 3/4″ 45 degree conduits. Attached to the conduit I used 3/4″ white PVC about 12″ long. One end cut at 90 degrees and the other at 45 degrees. I inserted the 3/4″ tubbing so the 45 degree point would dig into the ground better. The 3/4″ cross slides nicely over the 1/2″ PVC. So no matter what the terrain, the stand is always stable. I also made an other version where where instead of using 3/4″ PVC I used 1/2″ PVC with 3/4″ to 1/2″ reducer (no picture of that). That way you don’t need any 3/4″ PVC and can use the 2 leftover 1/2 PVC pieces that are 12″ long.

This looks like a very smart design--I'd like to try it myself when I have some time.

Air Rocket Gallery

Here are pictures and videos from people like you launching air rockets. If you send some of yours, I will post them here.

John Biegun, Science Teacher

John Biegun is the science teacher I wish I’d had. Among the many projects (check out his channel) are air rockets.

Rick Ramsey and his Science Club

Teacher Rick Ramsey sent me this photo from his science club: a rocket caught just after launch and still in the frame!

Matt Navia and his son William

Here's another picture with the rocket launched but still in the frame, sent by Matt Naiva upon his son William's birthday party.

How to Make Air Rockets

Note: The following instructions show you how to make and launch a high-flying air rocket. You need a launcher for it first.

What You Need

  • Magazine or thin catalogue
    This is the source of the paper for the rocket body. Use the kind of catalog or magazine that is held together by 3 staples. By opening up the magazine to the middle and pulling out the staples, you get double-length sheets of paper. These make long, seamless rocket tubes that fly very high.
  • Milk carton or cereal-box cardboard
    This is for the rocket fins. Milk carton is a little sturdier, but other thin cardboard will work.
  • Scissors, tape, ruler, clear plastic food wrap
    You only need a little of the food wrap. It will be part of a shock absorbing nose cone.
  • Rocket tube former
    This is the 2' piece of pipe you fattened with a couple of strips of wide tape in the last part of the "Making the Launcher" section.

Step 1   Form the rocket tube.

Open up a magazine or catalog to to the middle where the staple curls over. With a finger nail or knife, straighten it so it's easier to pull out. From the outside -- again with fingernail or knife -- pull the staples out.

With two of the sheets evenly together, roll them on the forming pipe. Of the two ways you could wrap the paper, wrap it the way that makes the longest tube.

The sheets should be wrapped tightly. If they are mushy, re-roll them.

Tape all along the seam to keep it from un-wrapping. You now have a rocket body.

Although we have taped the outside seam, sometimes --after extended use-- the inside seam can shift or the corner of the magazine catch when you try to mount it on the launcher.

The solution is easy. Slide the rocket body so that about half an inch is beyond the end of the forming tube (shown as a pink dashed "hidden" line in the illustration). Now you can see the end of the inside seam (black in the illustration). With a piece of tape (light blue) about an inch long, stick about half on the inside seam and fold the rest over to stick on the outside. When you put fins on the rocket next step, put them on this end.

Step 2   Cut out, form and tape on the rocket fins.

Note: Bill Lewis, a teacher at Knight High School who has made air rockets with classes 2nd grade up to 12th grade and also with my family, has come up with a fin variation different than the one described below. It's folded in the middle so it's double layer; taped on both sides. It looks sturdier and easier to tape on. It might weigh a slightly more, but I don't think that's a problem. Bill's PDF pattern is here. US Letter size     A4 size(outside US)      Let me know what you think.

Print out the fin patterns. (for both US letter size and A4) Check the printed paper to make sure it did not re-scale the size of the pattern. Some browsers and PDF viewers change the scale and the size of the printed pattern. Choose the print options that say something like "Actual Size" or "Scale: 100%."

Rough cut out two patterns and use tape "donuts" on the back to stick them onto milk carton or cereal box cardboard. Cut out the outline. In the illustration the rough-cut pattern is white on the orange cardboard. Notice that in addition to the outline being solid, there are also 3 short, solid lines going into the fin. Cut those, too, stopping at the dashed line.

When the cutting is done, fold on the dashed line. You can do this by putting a straight-edge exactly on top of the dashed line and pulling the tabs up, as shown in the illustration. Or line up the dashed line with a sharp corner and bend it.

Next bend two of the tabs the other way so they alternate in direction. These bent tabs --known as "flanges"-- will allow you to tape the fin on each side to the body, so it will be stronger.

Finally, tape the fins onto the end of the rocket tube -- the end that you taped at the end of step 1. Line up the fin with the end of the rocket, as shown in the illustration. Actually, it's three illustrations of the rocket being rotated clockwise to show the fin from several angles. The outer edge of the otherwise brown fin is pink, as a reference point.

Use two pieces of tape about 3" long-- one on each side of the fin. Notice in the other illustrations on the right that the tape (the outline of it shown as light blue) extends above and below the flanges. The tape end for the lowest flange will fold right into the inside of the tube. Press the tape on hard.Tape on the other fin on the opposite side.

Finally, bending the bottom of the fins a bit will make the rocket spin, making it more flight stable. The illustrations omit the flanges to concentrate on the bends. Notice that when viewing the close fin edgewise, the other fin appears to be bending the other way. But if you turn the rocket tube so the far fin in now close, the bend is going the same way as the other fin was.

Step 3   Close off the top.

We have to close off the top of the rocket so the blast of air from the launcher will be trapped, pushing the rocket up. I used block off the end with tape only, but that wasn't strong enough and there were leaks. Now I fold over the paper end of the first, then tape. Start by sliding the rocket to the other end of the forming tube so that 1/2" of the paper tube sticks out past.

  1. Again, in the illustration (1) the forming pipe appears as a dashed hidden line.
  2. With your thumb, push over part of the paper.
  3. Then push on the other side and push over the paper there.
  4. Now there are two peaks left. Fold those over one at a time, too.

Now when we tape the top, the paper at the end will give it sufficient strength.

Step 4   Make a soft nose cone.

We will make a rounded, soft nose cone for safety and efficiency. At subsonic speeds (less than about 750 miles per hour) a rounded nose cone slices through the air more efficiently than a pointed one. And of course a rounded front is safer. The softness of the nose will make it safer, too, and absorb some of the shock as the rocket hits the ground so the rocket tube doesn't get too banged up. It only takes a minute. Tear off a piece of clear plastic food wrap about 6" or so long and crumple it up. With a piece of tape about 4" long, tape the ball of plastic (yellow in the illustrations) to the top of the rocket, as shown. The tape (blue in the illustration) will form an upside down"U" with the middle curving around the top of the crumpled ball and the ends taped to the rocket tube. Apply another piece of tape perpendicular to the first. It might not be a perfect dome, but it is an approximation.

Step 5    Launch it!

Air rockets are safe coming down. Having one drop on your head might startle you, but it won't inflict injury. Going up is a different story. You need to have rules that keep a person mounting a rocket on the launcher from getting clobbered at point-blank range in the eye by an impulsive kid's unexpected stomp.

I suggest the following strategies:

Proper launch procedure means observing the following rules:

  1.  Always point the launcher straight up, never tilted.
  2.  Consider putting a box over the air bladder (soda bottle) while the rocket is being loaded. Do not remove it until the launch area is clear. Clear means 15 feet from the launcher.
  3. Always count down out loud from at least 5 so a launch never occurs unexpectedly.
  4. I could go on and say things like, “don’t launch rocks or toy cars, etc. with the rocket, but surely we have reached the point where common sense takes over.

Of course young kids have to be supervised, and you will have to decide your level of interaction. Once the basic ground rules are established and followed, I keep an eye on things while letting the kids do everything.

To launch a rocket slide it onto the vertical pipe-- all the way down. When everyone is clear, count down and stomp really hard on the middle of the soda bottle with one foot. Do not stomp on the end of the soda bottle because that will crack the bottle.

You'll need to blow up the bottle again before sliding the rocket onto the launcher for another launch. The only place you can do that is the opening at the top of the vertical pipe. Rather than put your your mouth directly on the pipe, make a fist around it and blow into your fist. You can make an air-tight seal. If people don't stomp on the end of the soda bottle it can easily last over 50 launches before needing to be replaced. You'll know when it finally does need to be replaced. Either it will be cracked so you won't be able to re-inflate the bottle, or it will be so crinkled that it won't inflate all the way. For instructions to make a quick bottle change adapter out of a melted bottle cap, click here. Here is Erik Herman's design in which you pump up an air reservoir instead of stomping.

Make a Quick-Change Connection for the Air Rocket Launcher

If you get tired of peeling off the tape that holds on the bottle onto the stomp rocket launcher every time you have to change it, consider this optional step. It involves melting part of a soda bottle cap with a candle so it fits onto the end of the launcher pipe. Then you just unscrew the old bottle and screw on the new one. It might take a couple of attempts to get it, but bottle caps are free and the process is really interesting.

Note: I got this e-mail which says there is an easier way. I have not had a chance to try it yet.

I have found an improved method for a "quick changer."

A sports bottle top will fit perfectly on a 2L soda bottle. If you are using 1/2" inside diameter tubing, then rip off the outside stopper on the sports bottle top and the little center piece of plastic. Then work the tubing on to the top and secure with a plastic zip-tie or a small hose clamp.

Stephen Lynch
Rose State College

What You Need for the Melted Cap Version:

  • 2-liter soda bottle caps (or same size)
    This is what will be melted and re-formed to make the quick-change part. Although you actually need only one to make the quick change part, you ought to have several handy. It might take a few to get it right. Most smaller carbonated beverage bottles also use the 2-liter size lid.
  • 1/2" PVC pipe
    After part of the bottle cap is melted, it will be formed by the pipe. It's the same pipe you made the rocket launcher out of. If you don't have a scrap piece lying around, perhaps you can use the vertical pipe from the launcher.
  • 2-liter soda bottle (or any that takes a 2-liter size lid)
    This holds the lid so your hands don't get near the flame and also guides the pipe as it re-forms the melted bottle cap. The pipe should be able to slide through the spout, but just barely--unable to wiggle much.
  • candle
    Any candle will work to melt the bottle cap. I just use a cheap birthday candle and hold it with a piece of aluminum foil formed around the base of it..
  • sturdy scissors, razor (or sharp knife), duct or other strong tape and a cup of cool water
    The water quickly cools down the re-formed bottle cap. A wet wash cloth or faucet would also work.

Step 1   Get Ready

Cut off the spout end of the bottle as shown. The razor can be helpful for starting the cut. Putting on a lid tightly helps keep the bottle from collapsing as you start the slice. If using a knife, be careful that it doesn't glance off as you start the cut.

If you haven't already put on a bottle cap, twist one on now. Have the pipe and water ready to go. Read through step 2 and step 3 so you know what to do once the bottle cap is melted.

Light the candle. The air around the candle must be still or it will be difficult to direct the heat where you need it the most.

Step 2   Melt the Lid

If you examine the bottle cap you will see there is a second, thinner circle of plastic pushed into the inside of the bottle cap. This "inner seal" will also be melted and formed. It usually takes about 2 minutes for the heat to travel from the other side of the cap enough to melt this inner seal, too.

Hold onto the bottle so that the cap is suspend an inch or two over the top of the candle flame. If the cap smokes, move it up and away from the candle more. You are going to smell melting plastic, but there should not be smoke.

Viewing from the top, look for changes in appearance in the bottle cap. First you will concentrate on directing to the middle of the cap, not lopsided to one side. Then you'll be looking for the signs that it's melted enough to form, but not so hot it melts a hole in the cap.

After a minute or so of heating, the inner seal appears to be a little puffed up (convex) as viewed from above. I think the puffing might be caused by the air trapped between the cap and the seal heating up and expanding.

Perhaps 15 or 30 seconds later part of the inner seal will take on a slightly shiny, wet appearance which indicates melting. Soon it will begin to droop down a little instead of puffing up. If the melting and drooping is NOT in the middle, try to direct more heat to the un-melted part.

Once you see the some drooping lift up and look at the cap from the BOTTOM. The pattern of melting on the bottom, too, will show you where to direct more heat.

When there is significant drooping that indicates the plastic is soft enough --but before there is a hole melted in the cap-- quickly move to the next step while the plastic is still hot. I know it sounds kind of vague about when to do that, but I don't there is any substitute for practicing on a few caps. Melting them is fun anyhow.

Step 3   Form the cap to a new shape.

Push the pipe into and through the neck of the bottle. Twisting the pipe slightly as it goes in helps control the motion. It will push against the soft spot on the cap and bulge it out to be about twice as long as the original bottle cap. The neck will keep the pipe perfectly centered. Interestingly, the bulge will hug the pipe and take its shape.

Quickly cool the bottle cap by dunking it in water. The plastic that forms the side of the bulge might seem a bit thin, but that's ok.

Step 4   Cut and attach the quick-change part.

Pull the pipe back out. Twisting might help again. Un-screw the lid off the bottle. Cut the end off the bulge. I think the easiest way to start the cut is by cutting off the corner formed by the end and the side, so you're actually cutting through 2 layers at once.

Twist and slide the plastic piece onto to the end of the launcher. Have about an inch stick out the other end. Tape the bulged out part to the pipe with duct or other strong tape.

Screw on a bottle and you're in business.

Consider other applications for this kind of connection between bottle and pipe. Some kind of funnel perhaps?

I'd like to know how this project goes for you. I'm happy to answer questions about it. Feedback from you is an important way for me to know what works and what needs clarification.

How to Make the Air Rocket Launcher

Note: You need to make a launcher to set off the rockets. The materials only cost few dollars. The launcher is simply an L shaped plastic pipe with legs to keep it standing. A soda bottle attached to one end provides the air reservoir.

What You Need

  • 1 ten foot piece of 1/2" PVC pipe
    Plastic pipe is very cheap and it comes in 10 foot lengths. You can cut --or even bend-- the ten foot section in half at the store for easy transport. The pipe carries the blast of air from the 2 liter bottle to the rocket, forms the two stabilizers,and provides a shape to form the rockets on. You can get this at hardware stores with well stocked plumbing departments, or less expensively at plumbing supply and building centers.
    Note
    PVC pipe is the White plastic pipe. Do Not Buy the tan colored “CPVC” pipe. One more confusing thing: even on the inside, 1/2″ diameter pipe is actually bigger than 1/2″ diameter. Go by what the writing says on the outside of the pipe, not by actually measuring
  • 1/2" PVC elbow
    Buy this from the same place you got the pipe. It is a tiny pipe fitting that will bend the pipe from horizontal to skyward.


    Note: As an alternative to white plumbing elbow pipe,  you can use 1/2″ PVC electrical “conduit” pipe, which is usually gray and usually used to contain electrical wiring. As you can see from the picture above (thank you, Guy Migneron of Canada), an added bonus is that the 90 degree elbow has a more gentle curve. This probably results in less friction as the air rushes through the tube. You find it in the electrical section rather than the plumbing section.
  • Plastic food wrap, strong string, and some rubber bands
    These lash the two short stabilizer pipes to the launcher, acting like feet to keep it from tipping over.
  • Hacksaw (or just a hacksaw blade) and a ruler or tape measure
    These are for cutting the plastic pipe to the right lengths.
  • 2-liter soda bottle
    This is the air bladder for the step rocket. You can get 50 stomps from a bottle before you have to replace it.
  • Wide tape
    This is for attaching the bottle to the pipe. Duct tape is my first choice, followed by packaging tape. Electrical tape will work if carefully applied.

Step1  Measure and cut the plastic pipe.

The 10 foot pipe length is enough for the following pieces with no waste. Notice that if you cut it according to the illustration above, it works even if you cut the pipe in half for easy transport. Any of the pipe pieces except the short 1' sections can be a few inches off without hurting launcher performance.

  • 1 piece 4' (48") pipe
  • 2 pieces 1' (12") pipe
  • 2 pieces 2' (24") pipe

The illustration above shows an easy way to cut the pipe without it flopping around. The double cross-cut saw style has the further advantage of allowing very young kids to safely participate in the cutting. If you are using a hacksaw blade without a frame, wrapping a piece of tape around one end makes a more comfortable handle.

Step 2 Bevel the inside corner of pipe on one end.

Start by making a chain of rubber bands about 16" long, un-stretched. Link the rubber bands as per the illustration.You can't lash very tightly with rubber bands, but rubber has a very high coefficient of friction. That means it is the opposite of slippery.

Make a cross with one of the 1' short pipes and the 4' long pipe, about 6" from the end of the long pipe. Hook the end rubber band around a pipe. Wrap the rubber band chain around the intersection in the two ways shown in the illustration, stretching it a little as you wrap. When you get it almost all wrapped on, hook the other end rubber band around a pipe again to keep it from unwrapping.

Next comes the wrapping of clear plastic food wrap. Cut off about a 5' piece and squeeze it to make it thin--more like a rope than a sheet. Tie a small loop in one end as shown. Hook the hoop around one of the pipe ends.

Start wrapping the clear plastic around the intersection, but wrap it under lots of tension. Pull on the plastic as hard as you can -- short of breaking it -- as you wrap.

Finally, wrap the string around the same way as the other two layers. The string, too, must be pulled very tight as it is wrapped. This is the last chance you have to squeeze the pipes together very tightly with the wrapping, short of doing it all over. Tie the end or tape it down.

Repeat the lashing with the other short pipe and the other end of the 4' pipe. Your assembly should look something like the illustration above.

Step 3  Taper and attach the 2' vertical pipe.

Tapering the outside of one end of the 2' vertical pipe makes it much easier to get the rockets on. I suppose the proper way to do it is with a file, but I find it's very easy to rub the pipe end on a concrete sidewalk (the gray, square thing shown in the illustration). Pulling the pipe while rotating it at the same time makes a smooth taper

The pipe "elbow" allows you to attach the vertical 2' pipe to the 4' horizontal pipe. I used to glue both pipes into the elbow. Now I only glue one--or none--because it can be much easier to transport and store the launcher when the vertical part comes off. Instead, to hold it on I use brute force. All the elbows I've ever seen have a taper, so I pound the pipes into them tightly. Just pounding them on like that holds them on.

When assembled, the two short pipe feet should keep the 2' pipe pointed up, even if bumped. If it falls over, go back to step two and lash it more tightly this time.

Step 4   Attach the bottle.

On the pipe end opposite from the elbow, tape on a 2-liter soda bottle using wide tape. Although the bottle can be stomped 50 or more times, eventually it will have to be replaced.

For that reason, it's a good idea to stick a little bit of the end back onto itself. This creates a no-stick tab that makes it easier to un-wrap the tape.

This advanced step rocket section shows how to modify the end so you only have to un-screw old bottles off and screw new ones back on.

Step 5 Increase the diameter of a forming pipe.

Strictly speaking, you're done with the launcher, but you have a 2' piece of pipe left over. You will make rocket bodies on this pipe by wrapping paper or other materials around the outside of these tubes. If you want to see what I mean, you can take a peek at the rocket instructions, but then come back and finish the forming pipe.

Rockets formed on the pipe as it is now will fit too tightly on the vertical pipe of the launcher. If we make the diameter of the forming pipe slightly bigger, however, the resulting rockets will load and fire easily.
The most durable way to increase the diameter of the forming pipe is with wide tape, usually duct tape. Cut off a piece as long --or slightly longer -- than the pipe. Note that it's a good idea to have someone help you because a piece of tape that long tends to curl, stick to itself and become unmanageable. The tape in the illustration appears slightly too short for the pipe. I drew it a little short to clarify how the long strip of tape wraps around the pipe.

Take care to apply the tape smoothly. I have found that the best way to avoid air bubbles under the tape and wrinkles in the tape is to have the pipe make contact with the middle of the tape, then carefully work outward to the edges.

Two pieces of duct ought to increase the diameter enough. If rockets are hard to put on the launcher, add another. If using a thin tape like clear packaging tape, start with three pieces. If the rockets get hard to fit onto the launcher, add some more tape to make the diameter of the forming pipe bigger.

Now that you've made the launcher, you're ready to start making rockets.

Homemade Air Rockets

Everyone who sees the air rocket the first time just can't believe how high it goes. - SciencetoyMaker

Introduction

If I had to pick just one science project that would appeal to the most people, this air rocket would be the one. Everyone who sees one the first time just can't believe how high it goes. It costs less than $3 to make the launcher, and the rockets are free.

Air rockets appeal to a vast range of ages. Pre-schoolers (under the watchful eye of an adult) can send rockets higher than their houses. Teenagers and adults can engineer rockets that go higher than the tallest trees. The rockets can take up helicopters and maple seeds and release them at the highest point.

Two sets of instructions will get you to launch: Instructions for making the launcher and Instructions for making the rockets.

How to Make the Air Rocket Launcher

The launcher is simply an L shaped plastic pipe with legs to keep it standing. A soda bottle attached to one end provides the air reservoir.

Quick Bottle Change Adapter

You can get 50 stomps from a bottle before you have to replace it. If you get tired of peeling off the tape that holds the bottle onto the stomp rocket launcher every time you have to change it, consider this optional step.

Air Rocket Gallery

People made air rockets and sent some pictures and videos.

I'd like to know how this project goes for you. I'm happy to answer questions about it. Feedback from you is an important way for me to know what works and what needs clarification.