User's Guide to Rapid Prototyping Todd Grimm Society of Manufacturing Engineers Rapid Prototyping Association of SME Dearborn, Michigan
Copyright 2004 Society of Manufacturing Engineers 987654321 All rights reserved, including those of translation. This book, or parts thereof, may not be reproduced by any means, including photocopying, recording or microfilming, or by any information storage and retrieval system, without permission in writing of the copyright owners. No liability is assumed by the publisher with respect to use of information contained herein. While every precaution has been taken in the preparation of this book, the publisher assumes no responsibility for errors or omissions. Publication of any data in this book does not constitute a recommendation or endorsement of any patent, proprietary right, or product that may be involved. Library of Congress Catalog Card Number: 2003114160 International Standard Book Number: 0-87263-697-6 Additional copies may be obtained by contacting: Society of Manufacturing Engineers Customer Service One SME Drive, P.O. Box 930 Dearborn, Michigan 48121 1-800-733-4763 www.sme.org SME staff who participated in producing this book: Rosemary Csizmadia, Editor/Production Supervisor Frances Kania, Administrative Coordinator Printed in the United States of America Cover photos courtesy of: 3D Systems (wheel support and SLA time lapse) Accelerated Technologies (valve) Z Corporation (cell phone housings and Quincy compressor) Ralph S. Alberts Co., Inc. (epoxy tool)
To my wife, Lori, with love Without your support, patience, and understanding, this book would not have been possible. vii
About The Society of Manufacturing Engineers (SME) The Society of Manufacturing Engineers is the world s leading professional society supporting manufacturing education. Through its member programs, publications, expositions, and professional development resources, SME promotes an increased awareness of manufacturing engineering and helps keep manufacturing professionals up to date on leading trends and technologies. Headquartered in Michigan, SME influences more than half a million manufacturing engineers and executives annually. The Society has members in 70 countries and is supported by a network of hundreds of chapters worldwide. Visit us at www.sme.org. About RPA/SME The Rapid Prototyping Association of SME (RPA/SME) focuses on the technologies and processes that help conceive, develop, test, revise, and manufacture new products to cost-effectively bring them to market faster. Concurrent engineering and design for manufacturability are embodied in rapid prototyping technologies, which include fused deposition modeling, stereolithography, selective laser sintering, laminated object manufacturing, solid freeform fabrication, layered manufacturing, and others. Rapid prototyping methods are timely and cost effective for large and small manufacturers alike. Beyond prototyping, however, rapid prototyping technologies are becoming production tools. Examples include producing consumable patterns for short-run casting or even rapid tooling for injection molding. In reverse engineering, a computer model created from scanning an object can be used to generate a physical copy of it. Design engineers, product engineers, tool engineers, and manufacturing engineers interested in this fast-moving area are members of RPA/SME. They are in industries ranging from automotive to shipbuilding, and medical manufacturing to general service bureaus.
Table of Contents Preface... xiii Acknowledgments... xv 1 Introduction... 1 Creating Understanding and Awareness... 2 What Is Rapid Prototyping?... 3 Detailed Technology Description... 5 Shades of Gray... 7 A Tool for Change... 8 Informed Decisions... 9 2 Overview... 11 Definition of Rapid Prototyping... 11 History of Rapid Prototyping... 14 Why Prototype?... 24 Benefits... 27 Overview of Applications... 31 Rapid Prototyping Systems Classifications... 38 Rapid Tooling and Rapid Manufacturing... 43 Future of Rapid Prototyping... 47 ix
3 The Rapid Prototyping Process... 49 Overview... 49 Process Detail... 51 Process Strengths and Limitations... 80 4 Classes of Rapid Prototyping Systems... 85 3D Printers... 87 Enterprise Prototyping Centers... 89 Direct Digital Tooling... 91 Direct Digital Manufacturing... 92 System Classification... 94 Specialization Replaces General Purpose...103 5 Applications and Benefits...105 Applications...105 Benefits...127 Conclusion...136 6 Rapid Prototyping versus CNC Machining. 139 Pragmatic Decisions...140 Process Comparison...141 Summary...158 7 Rapid Prototyping Technologies...161 Systems...161 Process Overview...162 Process Detail...164 Comparison of Prototype Properties...171 Comparison of Operational Properties...195 Comparison of Applications...204 Conclusion...216 x
8 Developing a Justification...217 In-House Operation versus Service Bureaus...217 Economic Justification...219 Hidden Costs...222 Additional Considerations...234 Conclusion...238 9 Evaluation and Implementation...239 The Challenge...239 Defining Realistic Needs...240 Evaluating Systems...243 Implementation...256 Conclusion...265 10 Rapid Tooling and Rapid Manufacturing...267 Definitions...267 Limited Use and Success...268 Rapid Tooling...269 Rapid Manufacturing...283 11 Moving Forward...291 Barriers to Growth...293 Future Developments...297 Conclusion...304 Appendix A: Case Studies...307 Rapid Prototyping Promotes More Design Iterations, Smoother Pilot Test...307 Snowshoe Design Hits the Fast Track...310 Finite Element Analysis Results Printed in 3D...312 xi
Ancient Greek Statue Reproduced with Rapid Prototyping...314 Technology and Innovation Used to Boost Aging Product...315 Process Comparison: Stereolithography and RTV Molding...320 Rapid Prototyping Assists Surgeons Planning Separation of Conjoined Twins...322 Rapid Tooling Cuts Processing Time by 50 75%...328 Rapid Prototyping Credited for Multi-Million Dollar Contract...331 3D Printer Applied to Functional Testing and Rapid Manufacturing...334 Chevy SSR Relies on Rapid Prototyping...336 Big Rigs Benefit from Rapid Prototyping...341 BioMolecular Models for Research and Education...343 Ski Binding Innovation Fueled by Rapid Prototyping. 345 PRO Series Power Fastening Tool Perfected with Rapid Prototyping...347 Appendix B: Additional Resources...351 Contributors...351 Manufacturers...356 Events...362 Information...362 Associations...363 Research and Education...364 Appendix C: Glossary...367 Index...397 xii
Preface For the past 13 years, I have been a passionate supporter of rapid prototyping. As an advocate of the technology, I have presented at industry conferences, published articles and white papers, and participated on advisory boards. The fundamental motivation for these activities has been to create greater awareness and understanding of the rapid prototyping technologies. It is for this same reason that I have written User s Guide to Rapid Prototyping. At times, the limited use of the technology has me baffled and frustrated. Having seen the powerful results that rapid prototyping can deliver, it amazes me that so few appreciate and experience these benefits. In an age of product development where better, faster, and cheaper is the mantra, how can anyone ignore the advantages of rapid prototyping and its ability to help companies achieve these three goals simultaneously? At other times, when I am a bit more pragmatic, I understand why so few choose to implement rapid prototyping systems or use the services of a rapid prototyping bureau. There are a hundred reasons not to use this new (relatively speaking) technology. Without facts and proof of the advantages, it can be easy to downplay or ignore the benefits and highlight any disadvantages to avoid the risk and effort of change. xiii
As you will see throughout this book, it is my belief, and the belief of many industry experts, that awareness, understanding, and education are the fundamental barriers to the growth of the industry. Of course, as with any tool, there are physical limitations that may be obstacles to its use. Yet, there is so little information available to help prospective users quantify the risks and limitations, and measure them against the benefits, to determine if rapid prototyping is a sound business decision. Lacking information, many find it easier to continue to use the tools with which they are comfortable. As Terry Wohlers stated in the 2000 edition of the Wohlers Report, the industry was in the chasm, a concept proposed by Geoffrey Moore in his book Crossing the Chasm. This is a period in the product life cycle where the aggressive, risk taking companies have adopted a technology, but the conservative, pragmatic types (the majority) have yet to be convinced of the benefits of investing hardearned dollars and significant time into a relatively new, and yet to be fully proven, technology. I believe the industry continues to be restrained by the effects of the chasm. I am a believer, a supporter, and an evangelist of rapid prototyping. My goals center on the fundamental belief that the rapid prototyping industry must help designers, engineers, executive management, and all others in the corporation to better understand the technology so that they can make informed business decisions. Is the technology right for every industry, business, product, and application? No. Is it worth considering? Absolutely. I want to begin breaking down the communication and knowledge barriers with this book. It is only one small step towards the goal of rapid prototyping becoming a widely used tool. But hopefully, it is the first step in your organization s journey to truly understand rapid prototyping. I hope that you enjoy the following discussion. And more importantly, I sincerely hope that I have contributed to a better understanding and appreciation of rapid prototyping. xiv
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