- Physical Science - Position and motion of objects
- Science and Technology - Abilities of technological design
Science Process Skills:
- Mathematical Connections
Bottle Rocket Launcher
- To construct a bottle rocket launcher for use with the Bottle
Rocket and Project X-35 activities.
Students construct a bottle launcher from "off-the-shelf" hardware
and wood using simple tools.
Consult the materials and tools list to determine what you will need
to construct a single bottle rocket launcher. The launcher is simple
and inexpensive to construct. Most needed parts are available from
hardware stores. In addition you will need a tire valve from an auto
parts store and a rubber bottle stopper from a school science experiment.
The most difficult task is to drill a 3/8 inch hole in the mending
plate called for in the materials list. Electric drills are a common
household tool. If you do not have access to one, or do not wish to
drill the holes in the metal mending plate, find someone who can do
the job for you. Ask a teacher or student in your school's industrial
arts shop, a fellow teacher, or the parent of one of your students
If you have each student construct a bottle rocket, having more
than one launcher may be advisable. Because the rockets are projectiles,
safely using more than one launcher will require careful planning
and possibly additional supervision. Please refer to the launch
Like a balloon, air pressurizes the bottle rocket. When released from
the launch platform, air escapes the bottle, providing an action force
accompanied by an equal and opposite reaction force (Newton's Third
Law of Motion). Increasing the pressure inside the bottle rocket produces
greater thrust since a large quantity of air inside the bottle escapes
with a higher acceleration (Newton's Second Law of Motion). Adding
a small amount of water to the bottle increases the action force.
The water expels from the bottle before the air does, turning the
bottle rocket into a bigger version of a water rocket toy available
in toy stores.
Materials and Tools:
- 4 5-inch corner irons with 12 3/4 inch wood screws to
- 1 5-inch mounting plate
- 2 6-inch spikes
- 2 10-inch spikes or metal tent stakes
- 2 5-inch by 1/4 inch carriage bolts with six 1/4 inch
- 1 3-inch eyebolt with two nuts and washers
- 4 3/4-inch diameter washers to fit bolts
- 1 Number 3 rubber stopper with a single hole
- 1 Snap-in Tubeless Tire Valve (small 0.453 inch hole,
2 inch long)
- Wood board 12 by 18 by 3/4 inches
- 1 2-liter plastic bottle
- Electric drill and bits including a 3/8 inch bit
- Screw driver
- Pliers or open-end wrench to fit nuts
- 12 feet of 1/4 inch cord
- Prepare the rubber stopper by enlarging the hole with a drill.
Grip the stopper lightly with a vice and gently enlarge the hole
with a 3/8 inch bit and electric drill. The rubber will stretch
during cutting, making the finished hole somewhat less than 3/8
- Remove the stopper from the vice and push the needle valve end
of the tire stem through the stopper from the narrow end to the
- Prepare the mounting plate by drilling a 3/8 inch hole through
the center of the plate. Hold the plate with a vice during drilling
and put on eye protection. Enlarge the holes at the opposite ends
of the plates, using a drill bit slightly larger than the holes
to do this. The holes must be large enough to pass the carriage
bolts through them. (See Attachment of Mending Plate and Stopper
diagram to the right.)
- Lay the mending plate in the center of the wood base and mark
the centers of the two outside holes that you enlarged. Drill
holes through the wood big enough to pass the carriage bolts through.
- Push and twist the tire stem into the hole you drilled in the
center of the mounting plate. The fat end of the stopper should
rest on the plate.
- Insert the carriage bolts through the wood base from the bottom
up. Place a hex nut over each bolt and tighten the nut so that
the bolt head pulls into the wood.
- Screw a second nut over each bolt and spin it about half way
down the bolt. Place a washer over each nut and then slip the
mounting plate over the two bolts.
- Press the neck of a 2-liter plastic bottle over the stopper.
You will be using the bottle's wide neck lip for measuring in
the next step.
- Set up two corner irons so they look like book ends. Insert
a spike through the top hole of each iron. Slide the irons near
the bottle neck so that the spike rests immediately above the
wide neck lip. The spike will hold the bottle in place while you
pump up the rocket. If the bottle is too low, adjust the nuts
beneath the mounting plate on both sides to raise it.
- Set up the other two corner irons as you did in the previous
step. Place them on the opposite side of the bottle. When you
have the irons aligned so that the spikes rest above and hold
the bottle lip, mark the centers of the holes on the wood base.
For more precise screwing, drill small pilot holes for each screw
and then screw the corner irons tightly to the base.
- Install an eyebolt to the edge of the opposite holes for the
hold down spikes. Drill a hole and hold the bolt in place with
washers and nuts on top and bottom.
- Attach the launch "pull cord" to the head end of each spike.
Run the cord through the eyebolt.
- Make final adjustments to the launcher by attaching the pump
to the tire stem and pumping up the bottle. Refer to the launching
instructions for safety notes. If the air seeps out around the
stopper, the stopper is too loose. Use a pair of pliers or a wrench
to raise each side of the mounting plate in turn to press the
stopper with slightly more force to the bottle neck. When satisfied
with the position, thread the remaining hex nuts over the mounting
plate and tighten them to hold the plate in position.
- Drill two holes through the wood base along one side. The holes
should be large enough to pass large spikes of metal tent stakes.
When the launch pad is set up on a grassy field, the stakes will
hold the launcher in place when you yank the pull cord. The launcher
is now complete.
Launch Safety Instructions:
- Select a grassy field that measures approximately 30 meters
across. Place the launcher in the center of the field and anchor
it in place with the spikes or tent stakes. (If it is a windy
day, place the launcher closer to the side of the field from which
the wind is coming so that the rocket will drift on to the field
as it comes down.)
- Have each student or student group set up their rocket on the
launch pad. Other students should stand back several meters. It
will be easier to keep observers away by roping off the launch
- After the rocket is attached to the launcher, the student pumping
the rocket should put on eye protection. The rocket should be
pumped no higher than about 50 pounds of pressure per square inch.
- When pressurization is complete, all students should stand in
back of the rope for the countdown.
- Before conducting the countdown, be sure the place where the
rocket is expected to come down is clear of people. Launch the
rocket when the recovery range is clear.
- Only permit the students launching the rocket to retrieve it.
Look up the following references for additional bottle rocket plans
and other teaching strategies:
Hawthorne, M. & Saunders, G. (1993), "Its Launchtime!," Science
and Children, v30n5, pp.17-19, 39.
Rogis, J. (1991), "Soaring with Aviation Activities," Science
Scope, v15n2, pp.14-17.
Winemiller, J., Pedersen, J., & Bonnstetter, R. (1991), "The Rocket
Project," Science Scope, v15n2, pp.18-22.