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  • How to build
    your own
    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 Crashes

        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
        Tree Recovery

        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
        HD Camera Test

        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
        HD Camera Test II

        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
        Rapid Deploy Parachute

        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 from 1,819 Feet

        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.

    • 2016
  • Research & Development
    • Research & Development Index
    • Deployment
      Systems
      • 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
      Systems
      • 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!

      • Thermal Imaging
        Pressure 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.

  • 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
    • 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.

    • 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.

    • 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.

    • Universal Fin Can

      U.S. Water Rockets is proud to take fin construction to the next level, by using 3D printing technology. Our initial effort resulted in a set of fins which are joined together by a cylindrical section that holds them in perfect alignment. This arrangment is commonly referred to as a "Fin Can".

  • 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.

    • Design
      Competition
      winning
      rocket

      Our team was recently asked to assist some students participating in a water rocket distance competition held by their school. We had never done any experiments in achieving maximum distance, so we were excited by the prospect of applying our experience in setting world records for altitude, as well as the chance to work with students in the STEM field.

  • 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
    • Downloads Index
    • LaunchPad AlTImeter™
    • 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. Note: this manual includes the ServoChron assembly, programming and operating manuals into one convenient file. This manual supersedes the previous revisions.

    • 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.

    • MD-80 Camera
    • 808 Keychain camera
      • Clock Set Instructions

        Instructions and examples showing how to set the clock in the 808 Car Keys Keychain Type #11 HD720P MiniDV Camera.

      • Datestamp removal

        808 Keychain camera Type #11 Firmware file disabling the timestamp feature. NOTE: This firmware works on all models.

      • Continuous Record

        Version 2 of the 808 Keychain camera Type #11 Firmware file enabling the "continuous recording" feature. This firmware adds the following: a) The camera will not split recordings into 20 minute clips, it breaks recordings up into 4GB segments instead. b) The timestamp is disabled. c) If the battery dies, the last clip is properly saved. NOTE: This firmware works on all models.

    • Downloadable Photo Screensavers

      U.S. Water Rockets has just announced a newly created photo documentary journaling their Experimental Water Rocket Launches in the form of a Microsoft Windows Compatible Screensaver for all PCs. The new screensaver details many of their flights and contains their world famous Fall Foliage Aerial Photos, which were shot in the peak of the leaf season in northern New York State. These Screeensavers are simply loaded with breathtaking views from high altitudes, and ground camera footage from dozens of launches that kids young, old and young at heart will enjoy.

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

How to construct a Launch Detect Acceleration Switch

Introduction:

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. You can see a video explaining the ServoChron™ 2 on our YouTube Channel.

    Materials Required:(See photo gallery for alternate materials)

    • 8" of #28 AWG solid copper wire (plated wire if possible)
    • 2" of #26 AWG solid copper wire (plated wire if possible)
    • 1 PET plastic soft-drink bottle
    • 1 Paper Clip
    • Solder

    Tools Required:

    • Wire Cutters
    • Soldering Iron
    • Sharp Pencil
    Fine gauge wire can usually be easily found by removing the insulation from stranded wire and pulling out the strands. It is best to try and find copper wire which is nickel plated to help prevent corrosion. The switch will not work if the wire corrodes or tarnishes, so the right wire is important.

Step 1: Create the circular switch contact eyelet:

Strip any Insulation off the #26 solid copper wire, then wrap the #26 wire around the tip of the pencil and twist the ends together. Use the thickness of the pencil lead as a guide to creating a 0.1" loop inside diameter. You can use a small nail or other thin rod in place of the pencil lead if you have something similar to substitute for the pencil.
Feel free to adjust the size to suit your personal needs. A larger eyelet will reduce the sensitivity of the switch but this may be a trait you desire. A less sensitive switch will be less likely to accidentally trigger while you are handling the rocket.
Slide the loop of wire off the pencil tip when it is completed and add a little solder to the pigtail. You should now have a wire eyelet with an inside diameter of approximately 0.1" and a short pigtail coming off the edge. The first component is now complete.
Gallery

Step 2: Turn the soft copper wire into hard copper wire:

Strip any insulation off the #28 wire, and wind the #28 wire around the pencil. Neatness doesn't matter. Just wind it around and then slide the wire coil off the pencil, then run it through your fingers to straighten it back out. Repeatedly coil and straighten out the wire several more times. A total of 10-15 times should be sufficient. What we are trying to accomplish by doing this is what is known as "work hardening" the copper. Copper becomes harder and stiffer as it is shaped and "worked", and loses stiffness when it is annealed with heat. Our goal is to "work" the copper to harden it into "spring" copper. We work harden the wire this way to eliminate the softness from the copper. ...
Gallery

Step 3: Coil the wire into a spiral:

Take the paperclip and bend away the one end leaving the wire protruding out, making sure the protruding wire is straight and round and free from burrs or defects. Next, coil the #28 copper wire around the protruding lead on the paper clip. Leave an inch or so of the end dangling. After coiling the wire, push the wire together to pack the coils side by side so they touch and form a perfect spiral. Keep going until you have about 1/2" of packed coil and then clip off the excess and pack the end down neatly.
Gallery

Step 4: Turn the spiral into a spring:

With your fingers, gently pull the coils lengthwise to spread them evenly out with a small gap between each coil. The overall length of the coil will only grow 0.1" to 0.2" in this process. Now you can remove the coil from the paper clip. You should now have a neatly wound copper spring with a wire leg on one end.
Gallery

Step 5: Determine a mounting location for the parts:

You will need to have a location on your electronics circuit board prepared for the g-switch. This design was created such that you only need to drop down a through-hole resistor package in the board location for the switch. You do not need to design a custom footprint for the switch, which is a nice feature. You can also simply mount the parts onto a small piece of plastic or wood and connect wires instead of using a printed circuit board. Use the following steps as a general guide for mounting.
Gallery

Step 6: Test the Spring:

If you take the copper spring and hold it in a pair of pliers, you will notice that it is very sensitive to shock forces. It will oscillate quite a bit with a very minor perturbation. This should give away the secret how this g-switch operates.
Gallery

Step 7: Mounting the contact eyelet:

Carefully solder the eyelet into one end of the resistor pads on the circuit board. Make sure it is slightly raised from the board and perpendicular to the resistor component package and vertical.
Gallery

Step 8: Mounting the spring:

Solder the leg of the spring into the opposite resistor package pad on the circuit board. The opposite and of the spring is inserted through the eyelet before soldering. Take care not to heat the spring too long or it will anneal and soften. You may wish to put the paper clip back inside the spring for the soldering step to draw away the heat from the copper wire. When finished with this step you may need to bend the leg of the spring around with the pencil point until the loose end of the spring is perfectly centered inside the eyelet. Adjust the spring until it is centered inside the eyelet and not touching the sides or any other metal parts on the circuit.
Gallery

Step 9: Make a cover for the delicate switch:

Cut a piece of the plastic soda bottle about 3/4" long and 1/2" wide. Curl it around the pencil and make it into a 3/4" long "U" shape. Continue to bend and form and work the plastic until it holds the desired shape. Next, Invert the plastic U and glue it in place over the top of the spring/eyelet on the circuit board. The plastic acts as a shield to prevent the g-switch from being bumped accidentally or knocked out of calibration.
Gallery

Finish:

The g-switch is now complete. Any shock perpendicular to the spring will cause it to oscillate and touch the eyelet, completing the circuit between the two pieces. An acceleration perpendicular to the spring will bend it to the side and also complete the circuit.
To use this switch in a circuit effectively you will need to latch the contact closure because the switch will open back up immediately after making contact. If you have a microcontroller circuit reading the g-switch, it is a good idea to use an interrupt pin triggering a software action upon the transition of the signal when the contact closes. The ServoChron™ hardware was specifically designed to work in just this manner. If you do not use a microcontroller then you will need to add a flip-flop or some other type of one-shot circuit to latch the signal when the contact closes.
The design can be scaled up or down in size if you prefer, and sensitivity can be adjusted by varying the length of the spring. A longer spring will be more sensitive because it has more mass and leverage. Sensitivity can also be changed by changing the eyelet diameter. A smaller eyelet will be more sensitive because the spring will not need to deflect as much to reach the contact point in the eyelet. Be careful in making the switch too sensitive as it has been known to respond to minute vibrations in the ground such as those caused by nearby cars or even thunder claps.
Gallery
Launch Detect Acceleration Switch Video Tutorial:
Creative Commons License Water Rocket Launch Detect Switch Construction by U.S. Water Rockets is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.