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    Water Rocket
    • Water Rocket Tutorial Index
    • Water Rocket Construction
      • Parachute

        A strong and reliable parachute design is very important to anyone wishing to develop a water rocket with a recovery system. Any system from a simple Air Flap mechanism to the sophisticated ServoChron™ electronic deploy system relies on a well made parachute. This tutorial will reveal the secrets to easily making a parachute that will safely recover your water rockets.

      • Bottle Coupler

        This tutorial will show a method for creating inter-bottle connectors which can be used to join together multiple bottles by the threaded necks. These bottle connectors are useful for Water Rockets because they allow for a modular approach to be applied to your rocket design, which simplifies construction and repair of a damaged rocket.

      • Bottle Cutting

        Nearly every water rocket design that you can construct will involve some sort of bottle cutting. This tutorial will show you an easy method for getting perfect cuts every time.

      • Constructing Removable Box Fins

        One set of Water Rocket components which are critical to a successful and stable flight are the fins. U.S. Water Rockets designed and tested a new idea for creating water rocket fins which is called the "Box Fin" design, to create a quick and easy method for adding fins to Water Rockets which were much more rugged than typical fins, yet easier to fabricate with a higher degree of accuracy. This tutorial will explain how to create a triple box fin for a water rocket.

      • Enhancing Removable Box Fins

        The first improvement we will make is to modify the fin design so that it is adjustable to fit multiple bottle diameters. The next improvement we will make is to alter the attachment method for the fins. If you fly in an area prone to landing in trees, you can modify the design so that it will break away from the rocket with less force.

      • Nosecone

        One of the most important components you will build for your water rocket is the nosecone. This tutorial will explain how to build a good looking nosecone that performs great too.

      • Corriflute Recycling

        A relatively new building material used in the construction of water rockets is a corrugated plastic sheet or corriboard. It is also known under the tradenames of Corriflute, Coroplast, IntePro, Correx, Twinplast, or Corflute. This tutorial explains how to repurpose used corriflute for your water rockets.

      • Bottle Label Removal

        This tutorial will show you how to prepare your bottles for Water Rocket Construction. To prepare your bottles, the labels and glue must be removed, and the bottles must be cleaned of all contamination from their contents and oils left from manufacturing or handling.

      • Bottle Label Removal V2

        This tutorial will show you another method how to prepare your bottles for Water Rocket Constrction. This involves removing the labels and adhesive from the bottles and making sure there are no oils on the bottle. Failing to do so can result in the rocket leaking or exploding under pressure, due to contaminated splices.

    • Launchers
      • Cable Tie Launcher

        What good is building a water rocket if you have no way to launch it? The launcher we will be constructing is a variation of the Clark Cable Tie launcher, as this is the most reliable launcher that is easy to make.

      • Launch Tube o-ring

        Revised instructions for adding the o-ring to the Clark Cable Tie Launcher launch tube which simplify the build and improve the design. We have put a lot of effort into simplifying the design to remove steps which involve precise measurements and part placement, to maximize the ease of construction.

      • Cable Tie Release Mechanism

        This tutorial shows how to add a Clark Cable Tie Release Mechanism to the 22mm Launch Tube fabricated in the previous tutorial. This tutorial shows the newly revised and simplified instructions for making the release.

      • Split Collar Launcher

        This tutorial shows how to create the latest type of water rocket launcher which uses the newest improvements.

      • Gardena Launcher

        This quick tutorial showing how to make a compatible water rocket launcher that uses a gardena hose quick release connector for the release mechanism. This type of launcher also works with any standard gardena nozzle in addition to our 3D printed nozzle design. If you have all the materials on hand you should be able to build this launcher in an hour or less and be out launching water rockets in no time!

    • Parachute Deployment Mechanisms
      • ServoChron™ Quick Start Guide

        The ServoChron™ is a low cost time delayed dual servo controller designed for use as a parachute deployment or staging mechanism for Water Rockets. There are other potential applications for the ServoChron™ as well. The core of the ServoChron™ is the Texas Instruments MSP430 LaunchPad. This $4.30US board is an inexpensive microcontroller hobbyist experimenting platform that you load our FREE application firmware into with a USB cable. The FREE ServoChron™ application firmware file created by U.S. Water Rockets turns the MSP430 LaunchPad into a user programmable dual servo deployment system timer/controller.

      • Launch Detect Switch

        This tutorial will show you have to construct a very reliable and lightweight acceleration switch which you can use to activate electronic systems on your rocket such as a ServoChron™ 2 Dual Servo Actuated Parachute Recovery System.

      • Parachute

        A strong and reliable parachute design is very important to anyone wishing to develop a water rocket with a recovery system. Any system from a simple Air Flap mechanism to the sophisticated ServoChron™ electronic deploy system relies on a well made parachute. This tutorial will reveal the secrets to easily making a parachute that will safely recover your water rockets.

      • Radial Deploy System

        Since it is the key to safely recovering a rocket and payload and all the time, materials, and labor that went into building them To insure the safe recovery of our fragile and expensive experiments and payloads, we decided that we needed to invent a parachute system that was more reliable than anything ever flown before. We dubbed this new design the "USWR Radial Parachute Deployment System", and it is a radical departure from traditional systems, because it relies on only one moving part. The system we designed met that goal and also has a number of other advantages over previous systems.This system is less expensive and time conuming to build, has less moving parts, and can be located more places on your rocket.

      • Axial Deploy

        The objective of this tutorial is to demonstrate how to build a completely new type of parachute recovery system for water rockets. This system was developed to fill the need for a reliable parachute recovery system that could be made from common materials which was very easy and fast to make. Historically, ease of assembly and reliability have been mutually exclusive goals. This prompted U.S. Water Rockets to take a "clean slate" approach to the problem. This tutorial will explain how to construct the latest version of the U.S. Water Rockets Axial Parachute Recovery System.

      • Hybrid Deploy

        The Hybrid Deploy System is our latest idea for improving water rocket systems to make them more reliable and easier to build. This system improves upon our previously published designs known as the Axial Deploy System, and Radial Deploy System. By combining the ease of construction of the Radial Deploy System, with the heavy duty capacity of the Axial Deploy System.

      • Launch Detect Switch

        This tutorial will show you have to construct a very reliable and lightweight acceleration switch which you can use to activate electronic systems on your rocket such as a ServoChron™ Single/Dual Servo Actuated Parachute Recovery System.

    • Splicing
      • Bottle Splicing

        In order to create larger Water Rockets with bigger pressure chambers than afforded by typical soft drink bottles, many enthusiasts have resorted to joining multiple bottles together using various methods which all are commonly referred to as "splicing". This tutorial will show you how to use this new method to create perfect splices that are easier to create and outperform traditional splices in both strength and appearance.

      • Bottle Label Removal

        This tutorial will show you how to prepare your bottles for Water Rocket Construction. To prepare your bottles, the labels and glue must be removed, and the bottles must be cleaned of all contamination from their contents and oils left from manufacturing or handling.

      • Bottle Cutting

        Nearly every water rocket design that you can construct will involve some sort of bottle cutting. This tutorial will show you an easy method for getting perfect cuts every time.

      • Tornado Tube Coupler

        Many teams build their rockets in this manner using a pre-manufactured commercial product used in school science experiments commonly called a "Tornado Tube" or a "Vortex Bottle Connector". The commercial versions typically cost $1.00US to $2.00US each. This tutorial will show how to make them for pennies each and without the expense and time consuming process of turning them on a lathe. This method could also be applied to other size bottles such as the wide mouth bottles that sports drinks often are supplied in. These bottle connectors are useful for Water Rockets because they allow for a modular approach to be applied to your rocket design.

    • Creating Panoramas

      This tutorial explains how to create a panoramic view using some free image stitching software which you may already have on your computer and were not even aware of!

    • Tree Recovery System

      If you have hobbies which involve things that fly such as RC Planes, Drones or Model Rockets, then chances are that you've had one which you were flying end up stuck in a tree. We've had this experience a number of times in the past, and we wanted to share our Tree Recovery System with you so that you may benefit from our design. In this Tutorial we will show you how to build and how to use our design, which is easy and inexpensive to make and works amazingly well.

  • World Records
    • World Record Index
    • 2004
      • September 2, 2004 1,421 feet

        On September 2, 2004 U.S. Water Rockets set a new single stage water rocket altitude record with an average altitude of 1,421 feet, beating the old record of 1,242 feet that was held by Anti-Gravity Research.

      • September 6, 2004 1,471 feet

        Just 4 days after setting the water rocket single stage world record, it was raised to 1,471 feet.

      • September 11, 2004 1,481 feet

        After 4 more days X-10 set a new water rocket altitude record of 1,481 feet

      • October 23, 2004 1,606 feet

        On a beautiful fall day with the autumn foliage in full glory, the water rocket altitude was raised to 1,606 feet (stunning autumn foliage can be seen in the onboard videos).

    • 2005
      • April 16, 2005 1,609 feet

        On the first launch day of 2005 a new single stage water rocket altitude record was achieved. The required two flights averaged at 1609 feet.

      • May 26, 2005 1,696 feet

        This record was described on the television show Mythbusters.

      • September 24, 2005 1,715 feet

        The shakedown flights for the new X-12 water rocket proved to be winners with a new world record of 1,715 feet.

    • 2006
      • April 29, 2006 1,787 feet

        The freshly rebuilt X-12 water rocket sets a new world record after nearly being destroyed in an October 2005 crash during a record attempt.

      • April 30, 2006 1,818 feet

        After setting a record the day before, the weather conditions were conducive to another record attempt. A new record of 1,818 feet was achieved as the 2 flight average.

      • May 8, 2006 1,909 feet

        On May 8th 2006, a new WRA2 water rocket single stage world record was set by the famous X-12 water rocket.

    • 2007
      • June 14, 2007 2,044 feet

        X-12 pushes the official water rocket single stage world record to over 2,000 feet with an average of 2,044 feet.

  • Launch Reports
    • Launch Reports Index
    • 2004
      • 8-22-2004

        X-10 Water Rocket crashes and results in the total loss of a video camera and altimeter earlier today during a shakedown flight of a Water Rocket designed to set the World Record for Altitude. The launch went perfectly, but when the rocket went through apogee at nearly 1,200 feet it deployed a parachute which somehow separated from the rocket.

      • 9-12-2004

        A recovery crew for U.S. Water Rockets successfully retrieved the World Record Holding X-10 Water Rocket from a precarious position in a tree, where it had been lodged for 3 weeks. This flight insured the development of our tracking and telemetry system.

      • 11-23-2004

        The successful construction & testing of the remarkable new C-7 payload bay, the first ever payload section to loft a High Definition Water Rocket Video Camera

      • 11-27-2004

        C-7 is the highest resolution Movie Camera to ever fly aboard a Water Rocket, and was designed to outperform its predecessor, C-6 in resolution and framerate. In the second round of test flights, C-7 performed spectacularly, producing very smooth clear video with every test.

    • 2005
      • 6-5-2005

        The latest round of test flights which allowed ground observers to view and photograph a new design parachute in action. The entire deployment process was easily visible with binoculars from the ground, making the performance of the new system easy to evaluate. As a backup, in case the ground observations failed to produce conclusive performance data, we installed an innovative "ChuteCam" system in place of the WRA2 required Apogee camera. The ChuteCam uses a series of prisms to bend light and give the ChuteCam a reverse angle view, perfect for observing the parachute unfurling behind the rocket after deploy.

      • 10-29-2005 Crash

        While attempting to set a new WRA2 record altitude, parachute failure dooms X-12 and inspires herculean data recovery effort to recover the video from the destroyed camera.

    • 2006
      • 6-6-2006 2,001 Feet

        Although not an official record due to a second flight did not occur due to lack of daylight, X-12 becomes the first Water Rocket ever to surpass 2,000 feet.

      • 7-19-2006 2,088 Feet

        X-12 reaches an unprecedented altitude of 2,088 feet (636 m) on a clear summer afternoon with great visibility and bright sunshine. Unfortunately, when the rocket was recovered the water tight bulkhead seals of the payload section appeared to have cracked under the tremendous acceleration of launch and allowed water to fill the electronics bay upon splashdown.

    • 2008
      • 12-26-2008 Project 3000

        Launch Report of our X-12 Carbon Fiber High Pressure Water Rocket conducted to test our new HD camera and electronics payload during freezing cold weather conditions which resulted in a near disaster when the parachute failed, only to be saved at the last second by a tree.

    • 2011
      • 11-25-2011 7 Cameras

        Our B-2 Water Rocket was test flown with an unofficial word record of 7 onboard cameras in order to record video of a test of some enhancements to our free ServoChron Servo Deploy Timer Software, and our newly invented Axial Parachute Deploy Recovery Ejection System. This Launch Report contains the details of the launch and the results of the flight, including failure analysis and data logs.

  • Research & Development
    • Research & Development Index
    • Deployment
      • Dual Deployment System

        The dual deploy system proved to be a resounding success and a quantum leap in safety. If either one or even both of the parachutes became tangled or failed to inflate, the separate rocket sections would be too unstable to fall ballistically to the ground. Instead, the sections would tumble slowly down, reducing the chance for injury or property damage on the ground due to a "lawn dart".

    • Launch
      • Split Collar Launcher

        Water Rocket launcher mechanisms are an important area of Water Rocket design which has received almost no attention by researchers for more than a decade. This Research and Development article introduces our completely new launcher design to the water rocket community, and the history of the evolution of this radical new design.

    • Tracking & Telemetry Systems
      • Ground Test

        A rocketeers worst nightmare is a lost rocket, to combat this we designed our own telemetry and tracking system. A ground test of our new telemetry and tracking system

      • Live Test

        A live test of the tracking system proved a range of 50,000 feet.

    • Tools
      • Bottle Cutting Tool

        The bottle cutting jig will cut a straight cut around your bottles to remove the bottom or neck when splicing or making nosecones.

    • Pressure Tests
      • Compressor Failure

        To construct a world record water rocket, we needed to do many pressure tests. On this test the compressor failed and caught fire. Then the test vessel self launched at 300PSI!

      • Bottle Stretch Test

        Does a water bottle rocket explode because the plastic bottle heats and softens when the air inside is expanding and stretching the plastic? We wanted to find out. The purpose of this experiment is to determine if bottle burst pressure is reduced because of the heat generated by the stretching bottle as it expands.

    • Chase Camera

      As early as 2003, we were experimenting with ways to get outside views of our water rocket. Back then we had been flying a camera inside a payload compartment that was meant to separate from the pressure vessel at apogee. This article shows the development of a new system which would record the entire rocket for the entire flight, rather than just the descent of the pressure vessel.

    • 3D Camera

      At that time, basic ordinary video cameras capable of shooting 3D were quite costly (and they never came down in price since 3D never caught on in a big way). Therefore, we decided the only way to accomplish what we wanted was to build a 3D Camera Rig that would allow us to use our specialized cameras to achieve the goal. The way to accomplished this is to somehow use two similar cameras in tandem to capture photos and videos for each eye, and then merge them in software to create 3D output.

    • Tower Camera

      We wondered what the view would be like to a person standing on the tip of a Water Rocket as it was launched hundreds of feet into the air, so we came up with an idea to make a tower to mount a camera on the top of a Water Rocket, so we could find out what it would look like from that point of view.

    • Self Aligning Fin Brackets

      We put our new 3D Printer to use making our fin brackets, but there's no reason something similar could not be made from scratch using fiberglass, plastic, wood, etc. The 3D Printer just makes producing a lot of brackets as easy as pressing a button, walking away, and coming back later to collect the parts. Using this technology also allows us to configure the printer to print the brackets as hollow shapes, meaning that they are very lightweight.

  • MSP430 Launchpad Projects &Utilities
    • MSP430 LaunchPad Index
    • Projects
      • Replace Male Headers

        This tutorial will show a clever trick which will make it extremely easy for anyone of any skill level to remove the male headers that are installed on the MSP430 LaunchPad without damaging the circuit board, and replace them with the female headers provided.

      • Horizontal Stabilizer

        This tutorial shows how to modify your MSP430 LaunchPad so that you can use it with both Breadboards, and BoosterPacks. This simple modification is very easy and costs almost nothing. You can have the best of both worlds by adding these "Horizontal Stabioizers" to your MSP430 LaunchPad.

      • Ruggedizing the LaunchPad

        This tutorial shows how to modify your MSP430 LaunchPad so that the removable jumpers will not come loose if your MSP430 LaunchPad is subjected to high accelerartion or vibration forces. This simple modification is very easy and costs almost nothing.

    • MSP430 Drivers
      • MSP430 LaunchPad Drivers

        This archive contains the MSP430 Application UART driver file necessary to communicate to the UART on the MSP430 Launchpad. MSP430 projects which communicate to the PC will use this driver.

    • ServoChron™
      • ServoChron™ Manual

        The ServoChron™ is a low cost time delayed single/dual servo controller designed for use as a parachute deployment or staging actuator mechanism for Water Rockets, or Water Rocket Propelled Vehicles. There are other potential applications for the ServoChron™, but this document focuses on the Water Rocket single/dual parachute deploy application. The ServoChron™ was created specifically to make servo controlled recovery and staging mechanisms easy to build, and affordable or everyone. Note: this manual includes the ServoChron assembly, programming and operating manuals into one convenient file. This manual supersedes the previous revisions.

      • ServoChron™ Firmware

        ServoChron™ Firmware file archive for the MSP430 Launchpad.

  • 3d Printing
    • 3d Printing Index
    • Star Wars Droid

      U.S. Water Rockets is proud to release this nearly ΒΌ Scale accurate droid replica for 3D printing. This replica robot from the Star Wars Universe was designed to be the most detailed and accurate 3D Printable Astromech droid you can print, with exceptional detail lacking in other printable models.

    • Gardena Nozzle

      A type of Water Rocket launcher that has been popular for well over a decade uses a garden hose quick release connector for the launcher mechanism. These connectors are often called Gardena connectors because of a popular brand of connector that these launchers and nozzles were made from. We used a CAD program called Alibre to create the custom nozzle object, and then printed it on a Rostock Max V2 3D Printer. We have also shared the 3D file for this custom 3D nozzle on thingverse.

  • Tips to increase performance & Altitude
    • Tips Index
    • Increase Altitude/
      Go Higher
      • Weight Reduction

        A lighter rocket will fly higher. Removing excess weight is one of the simplist ways to make your water rocket fly higher. This tip will show you how to make your water rocket, payload bay, camera, and deployment mechanism lighter.

  • LaunchPad AlTImeter
  • Manuals & Documentation
    • Manuals & Documents Index
    • Manuals
      • LaunchPad AlTImeter Manual

        Have you ever wanted to use an electronic altimeter to find out how high your rockets fly, but you have found that the commercially available altimeter products are too expensive? U.S. Water Rockets proudly presents the LaunchPad AlTImeter, a very low cost model rocketry peak recording altimeter with optional apogee detect output and servo motor control connection. With this "Do it yourself" project, you can save close to 80% or more of the cost compared to commercially available altimeter systems.

      • LaunchPad AlTImeter Firmware

        LaunchPad_AlTImeter Firmware file archive for the MSP430 Launchpad.

      • ServoChron™ Manual

        The ServoChron™ is a low cost time delayed single/dual servo controller designed for use as a parachute deployment or staging actuator mechanism for Water Rockets, or Water Rocket Propelled Vehicles. Note: this manual includes the ServoChron assembly, programming and operating manuals into one convenient file. This manual supersedes the previous revisions.

      • ServoChron™ Firmware

        ServoChron™ Firmware file archive for the MSP430 Launchpad.

    • Documents
  • Downloads
  • Water Rocket Resources
  • About USWR
  • Search
Member of the The Water Rocket Achievement World Record Association   Member since 2003


How to build a Cable Tie Style Water Rocket Launcher.


What good is building a water rocket if you have no way to launch it? This tutorial will explain in detail how to create a very easy to build, yet extremely robust and reliable water rocket launcher. The launcher has been designed so that no special tools or skills are needed to assemble it, and it uses commonly available parts which you can find at a hardware store or lying around the house.
The launcher we will be constructing is a variation of the Clark Cable Tie launcher, as this is the most reliable launcher that is easy to make. This launcher style is also very robust and reliable and will serve for many launches without breaking or needing any adjusting or maintenance at all. This type of launcher will work with virtually any type of water rocket from simple empty bottles to high pressure reinforced FTC rockets.
This tutorial will show you how to build a cable tie launcher like the one shown here.

Tools and Materials Required:

    Materials Required:
  • 3 feet of 1/2" PVC pipe
  • 3 inches of 3/8" PVC pipe (If you cannot find 3/8" PVC pipe for your launch tube, you can substitute in a piece cut from a chap-stik lip balm tube, or a piece of 1/2" copper pipe)
  • 1/2" 90 degree PVC elbow joint
  • 1/2" female to female PVC coupler
  • 1/2" Female PVC to male threaded adapter
  • 1/2" threaded PVC end cap
  • PVC/CPVC cement
  • #22 O-ring (0.1" thick and has a 1/2" inside diameter)
  • Tire valve
  • Garden Hose Washer
  • 1.5" diameter hose clamp
  • 6" Cable Ties or Zip Ties
  • PVC Coupler or Pipe for Collar (Size to be determined by your bottle size)
  • 3 feet (approximate) of wood 1/2" thick by 4" wide (or larger)
  • 2 1.5" radius U-Bolts
  • String or small rope (50+ feet long)
  • Small screw eyes
    Tools Required:
  • Scissors
  • Screwdriver
  • Electric Drill
  • Safety Glasses
  • Small carpenter's square
  • Wood Saw
  • Sharp Knife

Step 1: Cutting the PVC pipe components:

The launcher will require several pieces of 1/2" PVC pipe to make up the base. The dimensions are arbitrary in this design so they do not have to be exact. You may change the dimensions to suit your tastes or personal preferences. The pieces we will need areas follows:
About 8 inches for the base tube. About 4 inches for the riser tube. About 12 inches for the launch tube (this will vary depending on your rocket length).
We mark our 1/2" PVC pipe and cut it. There are several methods that can be employed to cut our pipe. You can use a simple and inexpensive tubing cutter which will cut a nice straight cut at a perfect right angle across the pipe. This style of cutter has a circular blade which is drawn into the pipe by a screw clamp mechanism. You gradually close the clamp down on the pipe as you rotate the blade around the circumference by hand. After a short time the blade will work completely through the pipe. A drawback of this type of cutter is that it leaves a small ridge of excess material around the outside of the cut edge. This can make the pipe difficult to insert into fittings. Also, due to the fact that the cutting blade is wedge shaped, the cut in the pipe will come out angled slightly toward the inside edge of the pipe wall. This isn't a problem usually, but on exposed pipe ends it can be a cosmetic flaw you may want to avoid.
Alternatively, pipe can be cut with a saw. Cutting carefully can result in a very nice cut, but it is quite difficult to get a perfectly perpendicular cut on a round object. That is why we recommend using a miter saw or a miter box for a hand saw. This type of tool will hold the saw perfectly perpendicular to the pipe and produce a perfect cut every time. Shavings and shards will likely be left on the edges of the cut. The blade may also leave grooves in the edge of the cut and this may be unsightly. We want to at least remove the shards and clean up the end of the pipe so it will be easy to assemble and glue.

Step 2: Sand the PVC pipes:

Some simple sandpaper can work miracles on our cut pipe. If you use the pipe cutter to cut your pipe, you can get rid of the ridge and even square up the cut. If you use a saw to make your cuts, you can clean up the shavings and smooth out the end for a perfect looking pipe end.

Step 3: Test fitting the components:

We will now temporarily assemble the base tube of our launcher now. Do not glue anything yet, we are just test fitting the launcher parts. First put the Elbow on one end of our cut pipe.
Next, we will put the threaded coupler on the other side. Remember, do not glue anything yet!!! You can already get a good idea how our launcher is going to look when finished.

Step 4: Drilling a hole for the Schrader (tire) valve:

This step illustrates a simple way to connect a Schrader valve stem to the water rocket launcher. This method is very simple and provides a built-in safety mechanism which is always a good thing. For those of you who prefer the "Presta" type valve stems, we will suggest some alternative methods you may use to connect those types of valves to the launcher as well, so don't despair
The first thing we will need is to take out the threaded PVC Pipe end cap and locate the center of the end of the cap. We picked out these fancy domed style caps because they have a bit of mold flashing at the exact middle of the top of the dome, which located the center with exact precision.
If you don't have a handy mark on your cap, use a pencil or pen to mark the center as best as you can. If you can spin the cap or roll it on a table top you would be able to see with the naked eye if the center mark is correct because the mark will not wobble when you get it in the right spot. Once you have the center position marked, you can drill a small pilot hole if you want to. Some people have better luck without a pilot hole in the cap and can keep the drill centered better without one. Whichever you prefer we will leave up to you.
The magic of the build happens when you choose the drill bit to make your hole in the end cap. Take your Schrader valve and notice that it has a small groove molded into the bottom of the stem. This normally fits through the hole in the wheel in the tire and is what holds it in place. That is the same thing we will do here. You will need to find a drill bit which is a little smaller than the groove to make your hole in the end cap. The size of the drill is not critical just make sure it's a little narrower than the groove.
With the drill bit selected, we can now begin to drill the hole. We have a drill press that makes a nice hole but you can use a hand drill as well. The nice part about the drill press is that it has a hole in the platform that we use to screw the pieces down from the bottom side and hold them in place.
When finished with the drill, you should end up with a threaded cap with a nice clean hole in the end. If the edges of the hole are not clean and smooth, you can correct this with a rolled up piece of sandpaper. Just insert the sandpaper into the hole and sand the edges nice and smooth. Don't sand the edges too much or you will enlarge the hole too far.

Step 5: Installing the Schrader Valve:

The next part of the launcher build is to install the Schrader valve. The way this is accomplished is the same way that the valves are installed in a wheel of a car. Many people are tempted to stick the valve through the hole and pull it through from the other side with a pair of pliers but this is not the way it is done. It could ruin the valve if you pull it through this way.
The proper method is to use a tool to insert the valve from the opposite side. If you do not have the special tool, you can use an awl or a Phillips screwdriver to accomplish the same thing. Insert the tool into the bottom of the valve and insert the valve in the hole.
A hard push of the tool will elongate the rubber valve stem and it will easily push the step through the hole into the groove and it will lock in place forming a perfect seal.
The completed valve assembly not only provides a connection for the air pump, but it will also act as a safety device. The Schrader valve is not glued in place and therefore it can provide some degree of safety because the valves will tend to pop through the hole if the pressure gets too high. We have tested this and it works with the launcher we made. You should test this on your own design because not all valves and caps will be the same.
If you use Presta valves, you can actually mount them by drilling a hole through the cap and putting a nut on either side of the cap to hold the valve in place, along with some glue to seal the hole. It's not quite as easy to make, but it will work.
The complete cap assembly can bow be screwed down onto the end of the launcher at the threaded coupler position. The threaded coupler just needs to screw into place. Do not worry about screwing it down too much because it could begin to force the valve out of the hole if you put too much pressure on it.

Step 6: Preparing to glue the splice:

Insert a piece of 1/2" PVC pipe (the basic form for your launch tube) into your water rocket as far as you wish it to extend inside. The pipe should not be so long as to touch to top of the rocket when the tube is completed, otherwise it could block the air flowing into the rocket. Keep in mind that the amount we measure here will be reduced by the amount that is inserted into the female-female PVC coupler so if you just push the tube in all the way and mark it you will have a part that is guaranteed to fit with a small gap at the top for the air to get in.
Mark the pipe where you want to cut it and saw it off as described earlier in this tutorial. To keep it simple, we're not going to measure any of this exactly, we will just put a mark on the launch tube using the neck of the bottle as a guide.
Once you have cut the PVC launch tube and cleaned up the end, you will now insert the pipe into the PVC 1/2" Female-Female Coupler. This coupler is used to join 2 pieces of 1/2" PVC Pipe together. In our case, we will be using it to form a base for the rocket nozzle and a ledge for the cable ties to affix to. This will prevent the ties from slipping off under pressure. We are using cable ties for our launcher as inspired by the fine work of Ian Clarke who invented this idea many years ago before disappearing from the water rocket scene.

Step 7: Adding the O-Ring seal to the Launch Tube:

We simply mark the o-ring location about 1/2" from the edge of the female-female coupler. This will be where the O-ring will seat inside the neck of the nozzle. The PVC launch tube is cut off at the mark you just made, and the ends of the cut pieces are sanded as smooth and as flat as you can possibly make them. This will be the sealing surface of the o-ring, so making it as neat and clean as possible is crucial to obtaining a perfect seal. Take the time to make sure these surfaces are perfectly smooth and then move to the next step.
The two cut pieces of the launch tube are combined with your 4" section of 3/8" CPVC pipe to create our launch tube o-ring seal. Insert the CPVC inner pipe inside the short piece of 1/2" PVC and glue it in place with PVC cement.
We have noticed some variation in the inside diameter of the 1/2" PVC pipes which makes inserting the CVPC inner pipe slightly difficult. The PVC cement will act as a lubricant until it begins to cure (after a very short time) so push them together fast or tap them together with a block of wood.
The short piece we have just glued will now be glued inside one end of the PVC 1/2" Female-Female coupler. If possible try and get the glue only on the mating surfaces. Putting on too much glue will cause it to slobber out all over the pipes and will leave stains on the launcher and make it look amateurish.
Slide the o-ring down the CPVC pipe until it reaches the bottom stop at the top of the 1/2" PVC pipe. If the o-ring doesn't slide easily, you can roll it down the pipe. Rolling and sliding will not hurt the o-ring.
Glue the other portion of the launch tube in place on the 3/8" CPVC pipe. Put slight pressure on the O-ring to form a nice seal. Tap or push the tubes together until the tubes touch the o-ring.

Step 8: Test Fit the O-Ring Launch Tube:

Test fit the newly designed launch tube in your rocket and see how well it fits. You should be able to push the o-ring seal into the nozzle of the rocket with a slight resistance as the o-ring compresses into the nozzle. The seal this o-ring forms is sufficient to seal against more pressure than the bottle is capable of holding. Remember never to exceed the recommended pressures of the pipe pieces you are using to build this launcher. Keep notes of the pressure rating of the parts and rate the launcher for the lowest pressure capable part you have used.

Step 9: Join the Launch tube to the base tube:

The 4" piece of PVC you have cut will become the interconnection between the base tube and the launch tube as shown. The new section goes between the 1/2" PVC elbow on the base and the 1/2" female-female coupler on the bottom of the launch tube. If you do not plan to color your PVC, you may glue the sections together and allow the glue to cure. When finished, you can slide the Garden Hose washer down the launch tube until it rests on the bottom of the launch tube firmly on top of the female-to-female connector at the bottom. The washer provides a flexible platform on which the nozzle will rest when the rocket is pressurized.

Step 10: Adding the Cable Ties:

Unroll about 8 inches of Duct Tape and place it sticky side up on your work table. Duct Tape is also sometimes referred to as Gaffer's Tape. Then, start placing table ties on the sticky tape, making sure to keep their heads even and the spacing perfectly aligned so the ties are perfectly parallel. Be sure and place the ties onto the tape with the flat side down towards the glue on the tape.
Continue to place cable ties one after another until you have enough to wrap completely around the PVC 1/2" Female-Female coupler on the base tube of the launcher. We know from experience that 17 of the ties we use will make one perfectly even wrap around the PVC coupler. If you use larger or smaller cable ties then you may need to test fit and adjust the number of ties. A good method is to put about 4 inches of ties onto the tape and then remove any extras when you go to mount them to the PVC pipes.
Slide a rocket or a bottle onto the launch tube and push it all the way down to the bottom where it will seat against the hose washer on the Female-Female coupler. Now, carefully take the Cable Tie mounted Duct Tape and place it on the Female-Female coupler as shown below. The heads of the cable ties should just overlap the bottle "grip" protruding from the neck of the bottle. Make sure to wrap the Duct Tape tightly and as evenly as possible.
Wrap the remaining tape around the cable ties and cut off the tape with a knife or scissors, then put the hose clamp over the cable ties and temporarily tighten the clamp until the ties are secure and cannot move around. The cable ties should all be perfectly even now and securely held in place by the hose clamp. You can now trim off the excess leads of the cable ties where they protrude from the bottom of the duct tape.

Step 11: Sizing and Fabricating the Cable Tie Release Collar:

The safety of the launcher depends heavily on this single part, so even if you don't care about the ease of use or the reliability of the o-ring seal, please put the effort into this piece to insure that your rocket is safe and secure on the launcher and will not launch by itself unexpectedly.
You will need to decide on the proper diameter for your clamp collar. It is important at this time that you sort out your rocket bottles and decide on a standard bottle to use with this launcher. If you examine your bottles closely, you will discover that some brands of soft-drinks use a different size flange on the neck of their bottles (see image below). The flange is used as the "handle" for the bottle, so it can be gripped by one hand and poured without slipping out of your grasp. Different bottling companies use different size flanges and you will need to decide which size you prefer to use because your launcher will be fitted for one size only.
The critical dimension for your clamp collar is the inside diameter. You will need to find a sturdy plastic tube with the appropriate diameter for your flange diameter. We found that a tube which is 1/8" to 1/10" larger than the flange diameter works extremely well. In our case we use the larger of our two bottle flanges and picked a 1.25" PVC pipe for the tube that will become the clamp collar for our launcher. If you see the image below, you can clearly discern that there is a 1/10" gap between the collar clamp and the flange. This gap will provide clearance for the cable ties to pass through but it is too narrow for the cable tie heads to pass through. This is the proper cable tie launcher setup.
Once you have found the correct diameter tube to form your clamp collar, you may cut the collar to length. The length of the collar is not critical, so we arbitrarily chose a length of 1.5 inches purely for aesthetic reasons. The only real requirement to the length of the collar is to provide a bit of extension below the cable ties when the collar is mounted so that there is room to tie a cable to rope to remotely operate the launcher. The collar should be cut as square and straight as possible because it will seat against the rocket perfectly straight this way and that will make the collar slides smoothly when in use. A crooked collar can bind up and jam or move with more difficulty.
You will now be adding some holes to the collar clamp so that a rope or cable can be attached and operated manually. Drill a hole completely through the collar at the exact center line of the tube. If the holes are not centered or uneven then the clamp will try and twist and could bind up during use. Make sure to drill holes sufficiently large enough to pass through the cable you will want to use.
If you are unsure of your ability to drill the holes straight on the first attempt, don't bother to sand the collar tube cut edges until after you have drilled the cable holes. This way if you screw up the holes, you haven't wasted time and effort sanding. Once you get the holes to your satisfaction you can then sand the collar. We simply sanded first because we have done this many times and have the experience for getting the holes straight on the first attempt.

Step 12: Testing the Release Collar:

Slide the collar down the top of the launch tube and over the cable ties. If necessary you can grip the ties with one hand and constrict them to allow the collar to pass over them. Slide of bottle down over the launch tube and push it down until it friction fits over the o-ring and seats against the washer on the base of the launch tube. If you have tightened the hose clamp on the bottom of the launcher you will want to loosen it up now so you can adjust it perfectly.
With the clamp loose you will move the group of cable ties as a unit up and down until they are overlapping the flange, Push the collar up so that it slides over the heads of the cable ties causing them to constrict around the flange. See the images below for reference and note how the heads of the cable ties overlap the flange and grab hold of it when the collar is pushed up. This is the secret how the launcher operates!
Press down on the bottle so that it is pressing firmly into the washer at the base of the launcher. The harder you press the better the secondary seal at the base washer will be. While keeping the pressure on the bottle, pull the cable ties assembly tightly down away from the flange as hard as you can pull and then tighten the hose clamp to secure the cable ties in this position. Be sure to leave enough room between the hose clamp and the bottom of the clamp collar so that it can move down all the way off the nozzle when it operates. The collar usually cannot pass over the clamp so you need to provide some distance for it to operate. You should try to get 0.75" to 1.0" between the top of the clamp collar and the bottom of the flange on the bottle when the clamp collar is fully retracted.
Practice operating the clamp a few times and see how it works. It should push all the way up against the rocket and sit neatly and squarely on the bottom of the bottle. It should slide easily down the cable ties and come to a stop against the hose clamp at the bottom with enough room for the cable ties to expand around the flange and allow the bottle to slide off the o-ring and up the launch tube. Push the rocket back onto the launch tube and allow the cable ties to surround the flange as the o-ring seals inside the neck. Push up firmly on the collar and notice the tension of the cable ties pulling taught against the flange causes the bottle to seat snugly against the washer at the base of the launch tube. That's perfect!

Step 13: Building the Launcher Base:

The base is made from a main spar of the base with a perpendicular spar on each end, forming legs. The main spar will be the main structure which the other parts will attach. The length of the body must be created so that it is long enough to accommodate the legs of the launcher and still allow clearance for the mounting hardware. If you neglect to leave room for the hardware you will find yourself with a launcher you cannot assemble because the holes you made for the U-bolts are underneath the place the legs are attached.
The distance between the U-bolts is actually the same length as the PVC pipe at the bottom of the launcher plumbing. This length places the U-bolts right over the PVC fittings on either end of the pipe. In our case we have 8" for the distance. You can use any place on the fittings that places the U-bolts in a secure location and measure that distance to determine the U-bolt spacing. Make a note of the number.
For our design, we measured the width of our launcher leg boards plus some extra spacing to allow for the nuts and mounting plate of the U-bolts. We simply set them in their rough positions and measured the space required. Since these dimensions are not critical, we rounded up to the nearest inch and came up with 3 inches of space required for each leg. We added the board length needed for 2 legs plus the length needed for the PVC tube which is 3"+3"+8", giving us 14" for our main body length. If this is too much detail work, you can just cut the legs to a reasonable size and then simply take the leg pieces and mock up the launcher in the final configuration and with the parts placed together like this you can make a mark on the main spar which will give a rough estimate of the correct length.
We marked out a 14" length of 1/2"x4" board for the main body spar of the base, and for our legs we used 1/2"x3" board. For the length of the legs, we picked an arbitrary length of 12". This length means one 4' board would yield four complete legs. There is nothing special about the length of the legs. A rule of thumb would be to make sure it's not shorter than 50% of the main body length. This will insure the legs are wide enough to be stable.
Notice that we have used a small carpenter's square to insure that our lines are all at perfect 90 degree angles. We want to try and make our cuts as square as possible when we make them. This only serves to make the launcher look more professional and really isn't critical to the operation in any way. How hard you work on the cosmetics is entirely up to you. You may want to put the effort into making a neat cut now because we will be giving tips on how to customize and dress up the launcher in the future and a neat job here will pay off handsomely then.
We now have the two legs and the main body board cut and ready for more work. Bear in mind that these proportions and board sizes are not very critical, and we picked the dimensions we did for reasons of aesthetics as well as to try and optimize the number of launcher pieces we could make using standard board lengths found in our local store. Please feel free to tweak the sizes to whatever suits your needs.

Step 14: Locate and mark the U-Bolt Holes:

Find the center line of the main body spar of the base. The easiest way to do that is to measure the width of the board and divide by two and then mark this width near each end of the board and use a ruler or some other straight edge to draw a line the length of the board making the center line. This mark will insure that the launcher turns out perfectly symmetrical when finished. If you have a calibrated eyeball you can visually locate the center line of the board. Find the center point of our main launcher body board, using the same method. Put a mark on the center line we just made at the point 1/2 of the length. This will give the exact center of the board and will insure the pipes are mounted in a nice symmetric way.
The location of the U-bolts is trivial math, because we took care in the earlier steps. Remember the length of the main PVC pipe at the bottom of the launcher? Well, we will be using that length now to precisely locate our U-Bolt holes.
Starting at the center point we marked on the base board, we will measure along the center line to locate the U-Bolt locations. The locations we want are exactly half the length of the PVC pipe which we recorded earlier. In our case we had an 8 inch long pipe, so we mark the board 4 inches from the center point on moth ends. We use our carpenter's square to make a line where each U-bolt will go. This line will be the center of the drilled holes for each U-Bolt, so we want to make the line as straight as possible and at a right angle to the board.
When finished making both locations for the U-Bolts, you can check your work by measuring the distance of each U-bolt from the end of the board closest to the spot. The two measurements should be equal. In out case our U-Bolts are each 3 inches from either end. If we were to place the 1/2"x3" plank we want to use for the legs on either end of the board we can also test that the holes are not going to interfere with the mounting of the legs.
To locate the holes for the U-Bolts on the lines we just drew, we will simply measure the width of the U-Bolts and divide by 2. This will result in the distance from the Main body board center line we must mark out on each of the drill lines we just made.
We now can measure the distance for each side of the U-Bolt along the drill lines and mark the positions. These locations are the places where we will be drilling holes for our U-Bolts. Carefully mark each hole location on the drill line for each end of the board. This will produce the hole locations we need for the two U-Bolts. Check your work by laying a U-Bolt on the board next to the drill marks we just made and verify that the drill marks really do line up with the tips of the threaded parts of the U-Bolt.

Step 15: Drill holes for the U-Bolts:

Our U-Bolts have take 1/4" nuts, so we want to make sure we drill the holes that are large enough to accept the U-Bolts. We picked a 5/16" drill bit so that our holes will have 1/16" tolerance. If you think you will not be able to drill your holes with that much accuracy, you can pick a larger drill bit which will give you some additional tolerance.
Loosely install the U-Bolts in the holes, and make sure everything fits properly. It's a good idea to put everything together in this way to look for possible problems with clearance or alignment issues. If necessary, you can drill out the holes you just made a bit larger with the next larger size drill bit if you have overestimated the accuracy of your drilling skills.

Step 16: Adding Legs to the Base:

Measure the length of the leg boards and divide this by 2 to determine the center point of the legs. This will be aligned with the center of the ends of the main spar. Place marks on the boards so you can assemble them accurately. It's best to sand the base board now because the legs will be attached next and this will make sanding the boards a lot harder.
There are countless methods of connecting these boards together. You can screw them together or nail them. These are the fastest and easiest methods, but we have found that they have problems. Nails and steel screws tend to rust, and that can leave a stain and look messy. Nails and screws are also prone to working loose under use. Our preferred method of connecting the legs to the main base board is to use glue. Of course the best glue for all things water-rocket happens to be PL Premium Polyurethane! We put a small amount on each leg where it attaches, and put the main base board on top.
We assemble each of the legs onto the base the same way, using a clamp to hold the boards firmly together until the glue has cured. If you have clamps like ours with rubber pads to protect your work, you don't really need to take any special precautions. if, however, you have metal faced clamps then you will want to put some scraps of wood under each contact point to protect your wood from getting marred or dented by the clamps.
Before you fully tighten your clamps, make sure the center markings on each leg line up perfectly with the center line markings on the ends of the main base board. Also make sure to use a square or right angle of some form to check that the legs are at a perfect right angle to the main base board. Tap the wood with a block of wood or the palm of your hand until you have it perfectly lines up and tighten the clamp fully. Don't over-tighten!
After the glue has fully cured, you can remove the clamps. You may want to sand off the center line marks and when you have finished beautifying your launcher you can then mount the plumbing loosely on the top of the launcher with the U-Bolts.

Step 17: Installing the remote release lanyard:

A remote release mechanism is necessary because we are working with pressurized air inside a plastic container which could burst and cause injury (possibly severe). You will need to be able to operate your launcher to fire the rocket from a safe distance. Whether you plan on holding your own friendly competition or choose to compete internationally with water rockets around the globe in the WRA2 record competitions, you will need to abide by a water rocket safety code which will specify the minimum safe distance you need to be from the rocket.
For our design, we are using a very simple and easy to fabricate release mechanism controlled by a lanyard made from carpenters string. The parts we need to obtain are some screw eyes and some strong string. We chose this fluorescent yellow string because of it's obvious high visibility. This is a safety feature to help prevent someone from accidentally tripping over the string and launching their rocket by mistake.
To help align our screw eyes, we are using our square to draw a line along the center line of the launch tube. Fortunately for us, there is a mold line exactly bisecting the 90 degree elbow at the base of our launcher, so we just lined our square up with the mold line and drew our line at the center of the launch tube onto the base board. If you don't have a mold line you can use your eye to estimate where the line should be or measure to find the location of the center of the launch tube and draw your line there. Mark some eye locations along the line we just drew. Make sure that the eyes were spaced farther apart than the width of the U-bolts so that the release string does not rub on them.
Use a small drill to make some pilot holes in the wood to insure the screw eyes were in the right spot and could not go in crooked from hitting the grain of the wood. It's always a good idea to make a pilot hole when screwing material together like this.
Measure out about three feet of the release string and fasten it to one side of the release collar. The other end of the string will feed through the eyelet on the side of the launcher which will face away from the operator and cross over to the screw eye on the opposite side of the launcher and back into the other eyelet from the side facing the operator to the back side and up to the hole in the opposite side of the release collar. Tie the release string onto the collar at this spot.
The remaining roll of release string will tie onto the piece we just connected to the launcher forming a "Y" shaped pull string. You will want to tie the main roll of string in a knot that can slide freely from side to side in such a way that it will center itself when pulled tight and will pull evenly on each side of the launcher.

Step 18: Adding Legs to the Base:

When you are finished, you can now give the launcher a quick test. Push the collar up onto the nozzle of the bottle and see that a yank on the release string will pull if off the nozzle without any trouble.
If you sense a lot of resistance you can apply some cooking oil spray to the cable ties and this will lubricate them so they slide freely. You may wish to apply some lubricant now regardless because you may want to launch some high pressure rockets and the lubricant will help release them with higher pressure inside, as the pressure can increase the friction of the collar.
At this point you can take your launcher and start flying! Congratulations!!!
Video Tutorial:
Cable Tie Launcher Video Tutorial
Creative Commons License Water Rocket Cable Tie Launcher by U.S. Water Rockets is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.