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    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 ¼ 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


LaunchPad AlTImeter

Servochron Single/Dual Servo Timer you build yourself!

If you are looking at the ServoChron, you may be interested in building the successor project, the LaunchPad AlTImeter. The Model Rocket Altimeter that you build yourself. Just go to the link http://www.uswaterrockets.com/documents/LaunchPad AlTImeter/manual.htm to find out more about this new project!

Table of contents:

Please click a links below to jump to a section of the documentation.


Introduction:

The ServoChron™ is a low cost time delayed 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 primarily focuses on the Water Rocket parachute deploy application. The ServoChron™ was created specifically to make servo controlled recovery and staging mechanisms easy to build, and affordable for everyone.
The core of the ServoChron™ is the Texas Instruments MSP430 LaunchPad. This board is an inexpensive microcontroller hobbyist experimenting platform that you program 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 servo deployment system timer/controller.
The custom firmware acts as a timer and servo motor driver which monitors a trigger switch and individually actuates up to two separate servo motors when a previously configured delay time for each has elapsed following the trigger condition. The trigger switch is most often used to detect the launch of the Water Rocket and the timer delay is set to the predicted time to reach apogee.
In a single servo application, the servo motor will then activate, and release a main parachute for a controlled descent.
In a dual servo application, one servomotor usually is used to deploy a small drogue parachute at apogee, and the second servo motor is used to deploy a larger main parachute some time later, when the rocket is closer to the ground. The dual servo setup can be used to prevent the rocket from drifting away while descending.
Another application commonly requiring dual servos is to deploy two independent parachute systems at apogee for redundancy. There are limitless applications to explore.
The ServoChron™ was designed and tested by the renowned U.S. Water Rockets, which have been featured on internationally broadcast programs like MythBusters. ServoChron™ is the result of many years of experience in setting Water Rocket World Records as well as recreational and scientific Water Rocket experiments.
  • Servo Deploy control for up to 2 servos
  • Independent Launch Trigger timer and/or Apogee Detect Trigger operation
  • Built on the low-cost MSP430 LaunchPad Platform
  • Operates on 3.7V-6V DC. You may use various power sources including a single lightweight Lithium Polymer rechargeable cell
  • User defined servo positions for up to two individual servos
  • User programmable delay for each servo from 0.000 to 30.000 seconds in 1 millisecond increments
  • USB Firmware update (with included cable! No special programming hardware to buy!)
  • Edge sensitive trigger inputs with automatic polarity detect
  • Dual trigger inputs capable of sensing contact open or close events shorter than 10 nanoseconds
  • Optional input for external apogee detect or radio control trigger
  • Innovative 2-button operator interface with easy to remember setup
  • 3 Status LEDs
  • UART (Serial) diagnostics mode
  • Dimensions: 2.0 x 2.6 inches (50.80 x 66.04 mm)
  • Weight : 0.635 oz (18 grams)
  • Includes testing and arming operational modes
  • Fully RoHS compliant. Contains legal levels of lead and hazardous materials

Purchasing information:

You will need to purchase your own MSP430 LaunchPad board, servos, and battery, and put the device together yourself with the simple instructions provided. See the assembly section for full parts list and prices.
[Back to Table of Contents]

Operation & Controls

All configuring of the user parameters is done using the custom designed Operator Interface of the ServoChron™. The interface controls consist of two pushbuttons and 3 LEDs. The pushbuttons are defined as follows:
  • S1 = Reset (Right) – This button will reset the ServoChron™ and is used to set up the delay timers.
  • S2 = Mode (Left) – This button is used to change modes and set up all configuration parameters.
The LEDs are defined as follows:
  • Power - This Green LED near the USB connector LED illuminates whenever power is applied to the ServoChron™
  • Red = Servo 'A" Status indicator - This LED is used to configure Servo 'A'
  • Green = Servo 'B' Status indicator - This LED is used to configure Servo 'B'
Figure 1: The Operator Interface
Figure 1: The Operator Interface
[Back to Table of Contents]

Configuration Modes:

The ServoChron™ has two configuration modes which must be set up prior to first use after programming the firmware. Once configured, the settings are stored in nonvolatile memory and will be remembered each time you power up or reset the ServoChron™, or until you choose to modify the settings. The operator interface was designed to maximize ease of use, and eliminate the need for any special tools, cables, cheat-sheets, software, or even a computer.

Note: If you are using a single servo, you should still program some sensible values for the unused servo settings.
The ServoChron™ configuration modes are:
Servo Positioning Definition Mode: This mode is used to define where the servomotor “home” and “deployed” positions are. Follow these steps to configure the two positions:
  1. Hold down the Mode button while connecting power to the ServoChron™. The Red LED will light steadily to indicate the Servo ‘A’ home position is being set.
  2. Tap the Mode button to change the “home” position in 30 degree increments until you reach the desired angle.
  3. Press and Hold the Mode button for longer than 1 second to save the “home” position. The Red LED will now go dark, and Servo ‘A’ will move into the "deployed" position.
  4. Configure the “deployed” position the same way as described for the “home” position.
  5. The Green LED will low illuminate indicating that you are now configuring the “home” position of Servo ‘B’. The positions for Servo ‘B’ are configured the same was as they are for Servo ‘A’. Set both positions for Servo ‘B’ now.
Delay Timer Setting Mode: This mode is used to program the delay time from trigger until each servo activation event. Follow these steps to configure the delay:
  1. Press and hold the Mode Button in and tap the Reset Button.
  2. Continue to hold in the Mode button, and release it when the delay time for Servo ‘A’ has elapsed.
  3. Wait additional time and then tap the Mode button to set the Servo ‘B’ delay time when the desired delay has elapsed.
Delay Timer Setting Mode: This mode is used to program the delay time from trigger until each servo activation event. Follow these steps to configure the delay:
  1. Press and hold the Mode Button in and tap the Reset Button.
  2. Continue to hold in the Mode button, and release it when the delay time for Servo ‘A’ has elapsed.
  3. Wait additional time and then tap the Mode button to set the Servo ‘B’ delay time when the desired delay has elapsed.
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Operation Modes:

Standby Operating Mode: This mode is entered by default at power up. When this mode is active, the servos will move to their "home" positions and The Red and Green LEDs will display a blinking pattern to remind you what the delay timer settings are. The pattern is one flash per second blink rate for the duration of each timer delay, followed by a two second pause with both LEDs on. This blinking pattern repeats forever. When this mode is activated, the state of the launch detect switch is read constantly and any change is detected. When a change is sensed, the triggered mode is activated.
Note: short delay times will result in a very small period of the LED "Off" off between 2 second pauses. If you set it very short, you nay not be able to see the LED in the "Off" state.
Triggered Mode: When triggered mode is activated, the status LEDs will begin to rapidly blink as the timer delays are counting down. When each timer delay has elapsed, the associated servo will move to the Deployed Position and once both servos have been actuated, the ServoChron™ will go into Deployed Mode.
(Optional) Apogee Detect Mode: If used this mode will override the timer delay and go into deployed mode. When used in this way the Apogee Detect trigger can be connected to an apogee detect system and the timer deploy can still function as a backup. Leave the apogee detect trigger input disconnected if you are not using this mode.
Deployed mode: This is the final mode which is activated once the ServoChron™ has actuated the servo(s). In this mode, both LEDs will blink once every 4 seconds to indicate the deployed mode is active. Both servos will be held in the "deployed" position for 2 minutes and then the servo outputs will be deactivated to conserve battery power. You must press the Reset Button or cycle power to exit this mode.
Test/Arming Mode: This mode is available when the ServoChron™ is in Standby Operating Mode and the Mode Button is pressed and held in. When this condition is detected, the servos will be forced to move to their "deployed" positions. You can use this to test your deploy systems, or you can use this mode to arm your deploy mechanisms if you have designed them with a positive latch. When the Mode button is released, the ServoChron™ automatically goes back into to Standby Operating Mode.

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Error Codes:

The Red LED indicates all error conditions by turning on steadily and briefly flashing OFF a number of times in a repeating cycle. The number of OFF flashes will reveal the error code.
The possible error codes are:
  • 2 Flashes = Time Configuration Error
  • 3 Flashes = Servo Configuration Error
Symptom: Possible causes: Corrective Action:
I get a Time Configuration Error You have set one or both time delay for longer than 30 seconds Reconfigure the delay times and be sure to set them both to values less than 30 seconds.
  You are powering up for the first time after loading firmware.  
I get a Servo Configuration Error. You have set the “Home” and “Deployed” positions of one or more servos to the same location. Reprogram the servo positions and be sure that each servo has different locations for each of the two positions.
  You are powering up for the first time after loading firmware.  

ServoChron™ Theory of Operation:

In normal use, the ServoChron™ powers up and directs the servomotors to move to their "home" positions.
  • ServoChron™ monitors the trigger input for a state change. In a typical Water Rocket this could be an acceleration or vibration switch or a simple pushbutton held depressed by the launcher. When the Water Rocket is launched, the trigger condition is detected.
  • ServoChron™ begins timing for the preconfigured interval calculated to approximate the time to apogee. When the Servo 'A' time interval has elapsed, the rocket would be at the apogee, and ServoChron™ directs the Servo 'A' to move to the "deployed" position. The mechanical motion of the servomotor is now used to release a parachute. This can be the main parachute, or a drogue parachute if you are using two servos. If you have dual servos configured and installed, when the Servo 'B' interval has elapsed, the rocket will have descended for a while, and ServoChron™ directs t Servo 'B' to move to the "deployed" position, releasing the larger main parachute.
  • If you are using the Apogee Detect Trigger this input will override the timer for Servo 'A' and cause it to move into the deployed position. This allows the ServoChron™ to be used as a servo activator for external apogee detection circuits. Note: Servo 'B' will also move to the deployed position after the Apogee Detect Trigger is detected plus the difference between the Servo 'A' and Servo 'B' timer intervals has elapsed, so the main/drogue feature is preserved.

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Assembly

    Tools Required:
  • Wire Cutter / Stripper
  • Soldering Iron
  • Solder

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Parts List:

To assemble a complete ServoChron™ Single/Dual Deploy System, a number of components are needed. The design has been thoroughly tested using the components listed below. Where noted, you may be able to locate equivalent replacement components which could suit your specific application.
  • 1x MSP-EXP430G2 - MSP430 LaunchPad Value Line Development kit
  • 1x MULTICOMP - R13-509A-05-BR - SWITCH, PUSHBUTTON, SPST, 3A, 250V (Or equivalent)
  • 1x Turnigy 160mAh 1S 130C Lithium Polymer Cell (Or Equivalent)
  • 12 inches of #22 Gauge Wire
  • 1 or 2 HXT900 9g / 1.6kg / .12sec Micro Servos (Or equivalent)
Optional Parts List: In addition to the components listed above, we chose to add the components listed below to the design. These components are merely extension leads for the battery and servo which allow the components to be plugged and unplugged easily, resulting in a modular design. If you omit these extension leads, you will need to solder the components together permanently using #22 gauge wire.
  • Mini Plug Extension for Micro Battery 10cm (5pcs/bag)
  • JR-Type Servo Extension 10CM Servo Lead (JR) 32AWG Ultra-Light (10pcs/bag)
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Wiring Diagram:

There are only 10 primary and 2 optional connections which must be made to the MSP430 LaunchPad Evaluation Kit Printed Circuit Board. These connections are illustrated in the diagram below. Note: If you are making a single servo version, you can leave off Servo B and the connections associated with it.
Figure 3. MSP430 LaunchPad Wiring Diagram
Figure 3. MSP430 LaunchPad Wiring Diagram

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Programming Instructions

The core of the ServoChron™ Deploy System is the MSP430G2231 (Or MSP430G2553 on newer LaunchPad boards) microcontroller from Texas instruments. This microcontroller contains flash memory which must be programmed with the ServoChron™ firmware to create the deploy system. Texas Instruments has created a very low cost evaluation board which contains all the circuitry needed to program the MSP430G2231/MSP430G2553, which is used as the main board for the ServoChron™.

Once you have made the connections requited in the Assembly Instructions to the MSP430 LaunchPad, the only step which remains is to download the firmware into the microcontroller. There are several ways to download the firmware, but this document references a FREE stand-alone application which can download the firmware file with a single mouse click.

Hardware Required:
  • MSP430 LaunchPad Evaluation Kit.
  • PC with Windows XP or later Operating System.
Software Required:

Programming Step 1: Download the Programming Software Tool:

Go to the website http://www.elprotronic.com/download.html and download the free program called "FET-Pro430 Lite". When the download has completed, read the installation instructions and follow the procedures for installing the software and the USB drivers included.

Programming Step 2: Run the FET-Pro430 Lite Software:

Find the programming tool icon on your desktop or in the program start menu of your PC and execute the application. Note: please make sure that you have followed all the USB driver installation instructions before running the application or connecting the USB cable to the MSP430 LaunchPad.

Programming Step 3: Load the firmware project file into the programming application:

Go to the "File" menu of the FET-Pro430 Lite application and click on "Open Project". You will then be presented with a file open dialog with which you will navigate to the directory where the firmware project file is stored. You select the firmware you wish to load and click "Open". The project file will then load into the programming application.

Programming Step 4: Program the Microcontroller:

Disconnect any batteries from the ServoChron™ and connect a USB cable from your PC to the USB port.

Warning: You must NEVER connect the battery and the USB cable at the same time.
You can damage your PC or the ServoChron™, or cause the battery to explode.

Once you have connected the USB cable you can press the "AUTO PROG." button to load the firmware file. The programming tool will report "PASS" when the operation is complete. Note: There are multiple versions of the MSP430 Launchpad on the market. This software will work on all of the currently available models but you may get a warning message when you program a newer model with this software. Confirm the message and continue the software download if this situation arises.

Programming Step 5: Finishing:

Close the programming software and disconnect the USB cable from your computer. You are now ready to use your ServoChron™. Before launching, you will need to configure the servo positions and time delay. Note: Please save these instructions and keep the programming software installed and up to date on your computer, because this tool will be used to program ServoChron™ Firmware Updates as well as future U.S. Water Rockets projects.
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Diagnostics

The ServoChron™ can optionally communicate directly with a personal computer using the MSP430 Application UART which is built into the MSP430 LaunchPad. This feature provides USB to RS-232 conversion hardware connected to the microcontroller which communicates using a secondary link over the USB debugger interface. With this mode, you can get a readout of all the current settings as well as diagnostic error codes which may help in troubleshooting.
Software Required:
To enable the UART Debug Interface, you may need to install one or two software packages on your Windows based PC:
Serial Terminal Software Application: Most installations of Windows prior to Vista will include a terminal application as part of the basic windows package. This is usually called "Hyterterminal". If you do not already have a terminal program on your PC, there are many open source terminal programs available. We recommend an application called Tera Term, which you can download from here: http://ttssh2.sourceforge.jp
MSP430 Application UART Driver: This software is needed to enable the USB to Serial Port Converter hardware built into the MSP430.
To install the MSP430 Application UART:
  1. Download the driver software from the following link: http://www.uswaterrockets.com/shared/MSP430_LaunchPad_Drivers.zip and extract it into a folder on your PC
  2. Plug in your MSP430 LaunchPad to a USB port on your PC.
  3. Open "Control Panel>System>Hardware>Device Manager" and find the entry for "MSP430 Application UART" in either "Ports" or "USB Controllers" (the exact location varies depending on windows version)
  4. Click on "MSP430 Application UART" and under "Drivers" there will be an "Update Driver" option. Click this button and select the option to load a driver from a specific location.
  5. Select the location where you saved the extracted drivers from step 1, and click OK. The drivers will now install.
  6. A port name/number will be assigned to the MSP430 Application UART and will be displayed in the Device Manager. It would typically be called COMx (where 'x' is a number). Write this value down for later reference.
Using the UART Diagnostics Mode:
To use the Diagnostic UART you must open your Terminal Program and set the communications port to the "COMx" value assigned to the MSP430 Application UART (from Step 6 above). When you select that port as the terminal communications port, you will also neet to set the parameters that the ServoChron™ firmware requires. To do this, find the dialog box where you configure the serial port properties and configure the settings. You will need to open the dialog and configure the following settings (see Figure 10) for your specific COM port number:
Once you have the terminal configured, you will see the diagnostic messages shown above (See Figure 9) whenever you press the Reset Button on your ServoChron™. You may use this mode to check your settings or to verify they are correct before a launch. You may also look for diagnostic messages which will display if an error is detected. Notes:
 Windows does not have very robust support for RS-232 over USB and so you can easily cause the driver to freeze up by unplugging the USB port while connected to the terminal. To avoid locking up the port, please be sure to close the terminal completely before unplugging the USB cable. You may also have to re-install the MSP430 Application UART software drivers if you move the USB connection to a different USB port on your PC.

Technical Support:

While this is a free project and we make no money from it, we will assist people who have questions in the ServoChron support topic on the Water Rocket Forum using the following link: ServoChron™ Technical support forum.
Please do not email us requests for technical support, use the link above and post your questions on the tech support forum.

Appendices


Appendix A: System Requirements:
  1. Texas Instruments MSP430 LaunchPad Evaluation Kit. This circuit board is the core of the ServoChron™.
  2. Power Source - Onl;y use a 3.7V to 6.0V battery. Confirm that it has sufficient current to power two servos.
  3. Servo Motors - We recommend a micro servo designed for use with a single LiPo cell. These servos are optimized for use with a 3.7V battery. Older servos designed for 5V systems may work but will require additional cells (more weight), and modified wiring.
  4. Trigger switch - This can be an off the shelf switch mounted to the rocket in such a way as to change state when the rocket leaves the ground, or something even simpler such as a bit of wire affixed to the ground that is loosely connected between the two connections for the trigger switch so that the connection is broken when the rocket lifts off and starts the timer.
Appendix B: Bill Of Materials (Dual Servo)
Suggested Parts
Qty Part Description
1 MSP-EXP430G2 MSP430 LaunchPad Value Line Development kit)
1 R13-509A-05-BR SWITCH, PUSHBUTTON, SPST, 3A, 250V
1 N160.1S.25 Turnigy nano-tech 160mah 1S 25~40C Lithium Polymer Cell
1 HK9727 Mini Plug Extension for Micro Battery 10cm
2 HK9710 JR-Type Servo Extension 10CM Servo Lead
2 HXT900 HXT900 9g / 1.6kg / .12sec Micro Servo
Appendix C: Copyright & Warranty:
ServoChron, and the ServoChron Logos are ™ and © 2011-2017 U.S. Water Rockets All rights reserved. U.S. Water Rockets, and U.S. Water Rockets Logo are ™ and © U.S. Water Rockets All rights reserved.
Notice: The information contained in this project is provided "AS IS" without warranty, express or implied. U.S. Water Rockets makes no warranty as to the reliability, accuracy, timeliness, usefulness, adequacy, completeness or suitability of the information.
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Creative Commons License Servochron™ single/dual servo water rocket parachute deployment timer by U.S. Water Rockets is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.