Model Rocket Design and Construction How to create and build unique and exciting model rockets that work! Third Edition By Timothy S. Van Milligan www.ApogeeRockets.com © 2008 by Timothy S. Van Milligan. All rights reserved. This book may not be repro- duced in part or in whole without written permission from the publisher, except in the case of brief quotations used in reviews. Published by Apogee Components, Inc., 3355 Fillmore Ridge Heights, Colorado Springs, CO 80907 USA. Visit us on the web at: www.ApogeeRockets.com Publisher’s Cataloging-in-Publication (Prepared by Quality Books Inc.) Van Milligan, Timothy S. Model rocket design and construction : how to create and build unique and exciting model rockets that work! / Timothy S. Van Milligan -- 3rd ed. p. cm. Includes bibliographical references and index. ISBN-13: 978-0-9653620-2-3 ISBN-10: 0-9653620-2-7 1. Rockets (Aeronautics)--Models--Design and construction. 2. Rocketry--Amateurs’ manuals. I. Title. TL844.V26 2008 629.47’5’0228 QBI08-600164 Printed in the United States of America We believe the information in this book is the best currently available. The author and publisher assume no obligation or liability for any advice furnished here, or for results obtained with respect to this information and advice. All such advice is provided gratis and the reader assumes sole responsibility for results obtained. About the Author imothy Van Milligan has been designing and flying his own model Trockets since 1976. After obtaining his degree in Aeronautical Engineering from Embry-Riddle Aeronautical Univer- sity in 1988, Tim worked as a launch op- erations engineer for McDonnell Douglas Corp. In this position, he helped assemble and launch the highly successful Delta II rocket for NASA and the U.S. Air Force. The author has also worked as a model rocket designer at Estes Industries. A few of the many rockets he designed for Estes include: CATO, Skywinder, Terrier/Sand- hawk, TurboCopter, and Omloid. Currently, Tim is the president of Apo- gee Components, Inc in Colorado Springs, Colorado, USA. The company offers a full line of rocket kits, motors, building supplies, books, educational materials for Model Rocket Propulsion, and Second rocketry, and the RockSim model rocket Stage Advanced Model Rocketry, Second design and simulation software. Edition as well as video books on rocket Tim has written over 200 articles about construction. the various types of model rockets for the In 2000, Tim was awarded the How- Peak-of-Flight e-zine newsletter, which is ard Galloway Award by the National As- published by Apogee Components, as well sociation of Rocketry. This recognition is as a number of national magazines and given for outstanding service to all sport newsletters. He has also been a competitor rocket flyers. in national and international model rocket In his spare time, the author gives competitions as a member of the F.A.I. educational rocketry presentations for the Spacemodeling team and N.A.R. His other Space Foundation and for other educa- books include: 69 Simple Science Fair tional organizations. He can be contacted Projects with Model Rockets: Aeronautics, for speaking engagements. Dedication For the many forward-thinking model rocketeers who desire to have more fun flying their own designs. Acknowledgments After 30 years in this hobby, I’m still Co., Inc., for use of the information on learning new stuff. I would like to thank the grading and selection of balsa wood. all those modelers who went before me, Similarly, thanks to Dr. Gerald M. Grego- blazing trails of their own into the sky, rek for allowing the reprinting of his boost yet who took the time to point other glider design rules. rocketeers, like me, in the right direction. Special thanks goes to David Flanagan Without these people, model rocketry who allowed me to reprint the sections on would not exist as it does today. cluster parachutes, gliding parachutes and Special thanks goes to those who spinning parachutes. Additionally, Norm helped with this book—Patrick McCarthy Dziedzic helped with the section on hemi- for technical review of the text and help spherical parachutes. in selecting photographs, Marc (Moose) Paul Fossey kept me involved in rock- Lavigne for encouragement, Edward etry by authoring the Rocksim software. LaCroix and Steven Bachmeyer for tak- That software was birthed by the first ing photographs for the first edition of the edition of this book, and is motivating book. In this third edition I also received modelers to tackle some very complex photographs from Scott Oliver, Geoffrey and interesting rockets. They then ask Kerbel, Kenneth Brown, Kent Burnett, my advice on how to achieve their rocket Bob Mosely, Moe Bertrand, John Man- dreams, which is how and why this third fredo, and had help with illustrations edition came about. from Dave Curtis and Eric Vandergriff. From a production standpoint, thanks George Gassaway graciously allowed me goes to Michelle Mason for editing and to reprint some of his helicopter plans, proofreading and to Jeff Lane (Brandango.us) and Mike Dorffler provided the scale data for page layout and cover design. drawings of the D-Region Tomahawk and Finally, thanks and love to my wife, MR-20 sounding rocket. Cindy, who allowed me the time to write Thanks also to Sig Manufacturing this book in the first place. Contents One: Getting Started .....................................................7 Two: Stability: Getting Rockets to Fly Straight .................23 Three: Drag Reduction and Aerodynamics ........................55 Four: Construction Tools ..............................................69 Five: Basic Raw Materials ............................................75 Six: Construction Techniques ......................................81 Seven: Building Higher-Powered Rockets ........................139 Eight: Painting and Decorating .....................................153 Nine: Repair Techniques .............................................159 Ten: Streamer and Parachute Recovery Systems ........165 Eleven: Designing for Glider Recovery .............................193 Twelve: Helicopter Recovery Design ...............................219 Thirteen: Scale Models ....................................................229 Fourteen: Payload Rockets ................................................237 Fifteen: Multi-Stage Rockets ..........................................241 Sixteen: Clustered Engine Rockets ..................................257 Seventeen: Rocket Engines .................................................265 Eighteen: Flight Testing .....................................................285 Nineteen: Displaying Your Completed Model .......................297 Twenty: Starting a Rocketry Club ....................................299 Twenty One: Computer Aided Rocket Design .......................... 301 Appendix A: Other Design Resources ....................................309 Appendix B: Bibliography ......................................................311 Glossary ...........................................................313 Index ................................................................325 1 Getting Started The Design Process The design process begins with a concept or idea. This is usually the hard- est step of the process to accomplish, because every rocket builder wants to create a new and unique model that no one has ever thought of before. Ideas are easy to copy, but new and different ones P 1-1 are very difficult to come up with. If you A basic sport have an idea, sketch it out on paper. If model. (Photo you don’t, turn in this book to the section by Steven A. that describes the different classifications Bachmeyer) of model rockets (page 11). You can also find ideas in the section on the various methods of returning your model to the ground (page 13). These methods are called recovery systems. Other places to get ideas for concepts is in the payload (page 235) and styling sections of this book (page 17). But, if you’ve already esigning and building successful paged through this book, you will have model rockets is a step-by-step pro- noticed that it is full of ideas for new Dcess with several different phases. types of rockets. Many great models are This book will discuss each part in suffi- developed by selecting the best parts from cient depth to help you develop successful several different rockets. rockets, but first it is important to know Whatever your idea, first sketch out the what makes a successful rocket flight— model, or at least write down a paragraph the goal of every rocketeer. describing it or its purpose. Second, determine the size and general Successful Flight Criteria layout of the rocket. At this point, you 1. Ignition should go directly to the section on basic 2. Lift-off rocket stability (page 23), and familiar- 3. Stable ascent ize yourself with all the concepts on how 4. Recovery system deployment to make your rocket fly straight. This is 5. Safe (damage free) landing the most important part of the design, as it will directly affect whether or not your A flight is considered successful when it model is successful. Choosing the size of safely completes the five individual phases: the rocket is completely up to the designer ignition, lift-off, stable flight (including the (you), but you might want to consider coast phase), recovery system deployment, some design constraints that would af- and safe landing. Without any one of these fect how big your rocket is. These might five phases, the flight would be termed include: