Robot builders bonanza 4th edition

ROBOT BUILDER’S
BONANZA


ABOUT THE AUTHOR
Gordon McComb has written 65 books and thousands of magazine articles—over a million
copies of his books are in print, in more than a dozen languages. For 13 years, Gordon wrote
a weekly syndicated newspaper column on computers and high technology, which reached
several million readers worldwide. He’s a regular contributor to SERVO Magazine and other
publications, and maintains an active Web site dedicated to teaching the art and science of
robot building.


ROBOT BUILDER’S
BONANZA
GORDON McCOMB

FOURTH EDITION

McGraw-Hill

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Copyright Act of 1976, no part of this publication may be reproduced or distributed in any form or by any means, or stored in a
database or retrieval system, without the prior written permission of the publisher.
ISBN: 978-0-07-175035-6

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contract, tort or otherwise.


For Lane and Firen,
keeping the legacy alive


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CONTENTS
Acknowledgments
Photo and Illustration Credits
Introduction

xxi
xxiii
xxv

Part 1—The Art and Science of Robot Building
Chapter 1—Welcome to the Wonderful World of Robotics!

3

What the Adventure Holds

3

Why Build Robots?

4

The Building-Block Approach

6

Lower Costs, Better Bots

6

Skills You Need

7

Do It Yourself, Kits, or Ready-Made?

9

Thinking Like a Robot Builder

12

Chapter 2—Anatomy of a Robot

13

Stationary versus Mobile Robots

13

Autonomous versus Teleoperated Robots

14

Tethered versus Self-Contained Robots

15

So, What’s a Robot, Anyway?

16

The Body of the Robot

17

Locomotion Systems

22

Power Systems

24

Sensing Devices

25

Output Devices

27

Where the Word “Robot” Comes From

27

Chapter 3—Getting Parts

29

Local Electronics Stores

30

Online Electronics Outlets

30

Using FindChips.com to Locate Parts

30
vii


viii

CONTENTS

Specialty Online Robotics Retailers

31

Hobby and Model Stores

31

Craft Stores

32

Hardware and Home Improvement Stores

33

Samples from Electronics Manufacturers

33

Finding What You Need on the Internet

33

Shop Once, Shop Smart

34

Haunting the Surplus Store

34

Getting Parts from Specialty Stores

35

Scavenging: Making Do with What You Already Have

36

Getting Organized

37

Part 2—Robot Construction
Chapter 4—Safety First (and Always)

43

Project Safety

43

Battery Safety

44

Soldering Safety

44

Fire Safety

44

Avoiding Damage by Static Discharge

45

Working with House Current

47

First Aid

47

Use Common Sense—and Enjoy Your Robot Hobby

48

Chapter 5—Building Robot Bodies—the Basics

49

Picking the Right Construction Material

49

In Review: Selecting the Right Material

52

Robots from “Found” Parts

53

Basic Tools for Constructing Robots

54

Optional Tools

57

Hardware Supplies

57

Setting Up Shop

58

Chapter 6—Mechanical Construction Techniques

59

First Things First: Eye and Ear Protection

59

Plan, Sketch, Measure, Mark

60

Drilling Holes in Things

60

Cutting Things to Size

64

Using Portable Power Tools

67

Getting Work Done Fast with Air Tools

68


CONTENTS

Chapter 7—Working with Wood

ix

69

Hardwood versus Softwood

69

Planks or Ply

69

The Woodcutter’s Art

72

Chapter 8—Build a Motorized Wooden Platform

80

Making the Base

80

Building and Attaching the Motors

83

Building and Mounting the Wheels

84

Attaching the Ball Caster

84

Using the PlyBot

85

Variations on a Theme

85

Chapter 9—Working with Plastic

87

Main Kinds of Plastics for Bots

87

Best Plastics for Robotics

89

Where to Buy Plastic

89

The Ins and Outs of Rigid Expanded PVC

90

How to Cut Plastic

91

How to Drill Plastic

93

Making Plastic Bases

93

Making Plastic Frames

95

How to Bend and Form Plastic

96

How to Smooth the Edges of Plastic

96

How to Glue Plastic

96

Using Hot Glue with Plastics

98

How to Paint Plastics

98

Household Plastics for Bot Constructions

98

Chapter 10—Build a Motorized Plastic Platform
Making the Base

100
100

Attaching the Motors

102

Fitting the Wheels

104

Attaching the Ball Caster

104

Using the PlastoBot

104

Altering the PlastoBot Design

105

Chapter 11—Working with Metal

107

All About Metal for Robots

107

Measuring the Thickness of Metal

109


x

CONTENTS

What’s This about Heat Treatments?

110

Where to Get Metal for Robots

110

Recap of Metals for Robotics

110

Metal from Your Home Improvement Store

111

Metal from Craft and Hobby Stores

113

The Metalsmith’s Art

114

Chapter 12—Build a Motorized Metal Platform

122

Making the Base

122

Using the TinBot

127

Chapter 13—Assembly Techniques

129

Screws, Nuts, and Other Fasteners

129

Brackets

135

Selecting and Using Adhesives

136

Chapter 14—Rapid Prototyping Methods

144

Selecting Lightweight Robot Materials

144

Cutting and Drilling Substrate Sheets

146

Rapid Construction with Semipermanent Fasteners

147

Chapter 15—Drafting Bots with Computer-Aided Design
Making Drilling and Cutting Layouts

152
152

File Formats for Vector Graphics

158

Using Laser-Cutting Services

158

Producing “Quick-Turn” Metal and Plastic Prototypes

159

Chapter 16—Constructing High-Tech Robots from Toys

160

Erector Sets

160

Fischertechnik

161

K’NEX

162

Other Construction Sets to Try

162

Construction with Snap-Together Components

163

Specialty Toys for Robot Hacking

165

Making Robots from Converted Toy Vehicles

166

Chapter 17—Building Bots from Found Parts

170

A Dozen Ideas to Get You Started

170

Experimenting with “No-Cut” Metal Platform Designs

171

Using Wood and Plastic Samples

175

Keep Your Eyes Peeled and Your Tape Measure Out

176


CONTENTS

xi

Part 3—Power, Motors, and Locomotion
Chapter 18—All about Batteries

179

An Overview of Power Sources

179

Batteries for Your Robots

180

Understanding Battery Ratings

183

Recharging Batteries

187

Robot Batteries at a Glance

187

Common Battery Sizes

187

Increasing Battery Ratings

189

Chapter 19—Robot Power Systems

190

Power and Battery Circuit Symbols

190

Using a Premade Battery Pack

191

Making Your Own Rechargeable Battery Pack

192

Using Battery Cells in a Battery Holder

193

Best Battery Placement Practices

195

Wiring Batteries to Your Robot

196

Preventing Reverse Battery Polarity

197

On the Web: How to Solder a Barrel Plug onto a Battery Holder
or DC Wall Transformer

198

Adding Fuse Protection

198

Providing Multiple Voltages

199

Regulating Voltage

201

Dealing with Power Brownouts

207

Battery Voltage Monitors

208

Chapter 20—Moving Your Robot

209

Choosing a Locomotion System

209

Locomotion Using Wheels

211

Locomotion Using Tracks

215

Locomotion Using Legs

216

Locomotion Using Other Methods

217

On the Web: Managing the Weight of Your Robot

218

Chapter 21—Choosing the Right Motor
AC or DC Motor?

219
219

Continuous or Stepping Motor?

220

Servo Motors

220

Motor Specs

221


xii

CONTENTS

Testing Current Draw of a Motor

224

Dealing with Voltage Drops

228

Avoiding Electrical Noise

229

Chapter 22—Using DC Motors

230

The Fundamentals of DC Motors

230

Reviewing DC Motor Ratings

232

Controlling a DC Motor

232

Motor Control by Switch

232

Motor Control by Relay

234

Motor Control by Bipolar Transistor

239

Motor Control by Power MOSFET Transistor

241

Motor Control by Bridge Module

244

Controlling the Speed of a DC Motor

247

Bonus Projects: Interfacing to Motor Bridge Modules

248

Chapter 23—Using Servo Motors

249

How R/C Servos Work

249

Control Signals for R/C Servos

251

The Role of the Potentiometer

253

Special-Purpose Servo Types and Sizes

253

Gear Trains and Power Drives

254

Output Shaft Bushings and Bearings

254

Typical Servo Specs

255

Connector Styles and Wiring

256

Analog Versus Digital Servos

257

Electronics for Controlling a Servo

258

Using Continuously Rotating Servos

260

Modifying a Standard Servo for Continuous Rotation

261

Using Servo Motors for Sensor Turrets

265

Chapter 24—Mounting Motors and Wheels

266

Mounting DC Motors

266

Mounting and Aligning Motors with Aluminum Channel

269

Mounting R/C Servos

270

Mounting Drivetrain Components to Shafts

272

Mounting Wheels to DC Gear Motors

273

Mounting Wheels to R/C Servos

274


CONTENTS

xiii

Attaching Mechanical Linkages to Servos

276

Drivetrain Components for Robotics

277

Using Rigid Flexible Couplers

278

Working with Different Shaft Types

282

Everything You Always Wanted to Know about Gears

283

Chapter 25—Robot Movement with Shape Memory Alloy

287

Shape Memory Alloy Comes to Robotics

287

Basics of Shape Memory Alloy

287

Using Shape Memory Alloy

288

Operating SMA Using a Microcontroller

290

Experimenting with SMA Mechanisms

291

Using Ready-Made SMA Mechanisms

292

Part 4—Hands-on Robotic Projects
Chapter 26—Build Robots with Wheels and Tracks
Basic Design Principles of Rolling Robots

297
297

Two-Motor BasicBot

304

Bonus Project: Double-Decker RoverBot

306

Building 4WD Robots

306

Building Tank-Style Robots

309

Chapter 27—Build Robots with Legs

318

An Overview of Leggy Robots

318

Selecting the Best Construction Material

321

Scratch Build or Parts Kits

322

Leg Power

324

Walking Gaits for Legged Robots

327

Build a 3-Servo Hexapod

328

Creating X-Y Servo Joints

335

Bonus Project: Build a 12-Servo Hexapod

338

Chapter 28—Experimenting with Robotic Arms
The Human Arm

339
339

Degrees of Freedom in a Typical Robotic Arm

340

Arm Types

340

Actuation Techniques

343

Build a Robotic Wrist

344


xiv

CONTENTS

Build a Functional Revolute Coordinate Arm

345

Build a Robotic Arm from a Kit

350

Chapter 29—Experimenting with Robotic Grippers

352

Concept of the Basic Gripper

352

Two-Pincher Gripper

353

Tool Clamp Gripper

355

On the Web: More Gripper Plans

359

Part 5—Robot Electronics
Chapter 30—Building Robot Electronics—the Basics

363

Tools for Electronics You Should Have

363

Making Electronic Circuits—the Basics

370

Understanding Wires and Wiring

370

How to Solder

371

Using Headers and Connectors

375

Using Clip-on Jumpers

377

Good Design Principles

377

RoHS Demystified

379

Chapter 31—Common Electronic Components for Robotics

381

But First, a Word about Electronics Symbols

381

Fixed Resistors

382

Potentiometers

388

Capacitors

390

Diodes

394

Light-Emitting Diodes (LEDs)

396

Transistors

399

Integrated Circuits

400

Switches

402

Relays

404

. . . And the Rest

405

On the Web: Stocking Up on Parts

406

Chapter 32—Using Solderless Breadboards

407

Anatomy of a Solderless Breadboard

407

Steps in Constructing a Solderless Breadboard Circuit

411


CONTENTS

xv

Making Long-Lasting Solderless Circuits

411

Mounting the Breadboard to Your Robot

412

Tips for Using a Solderless Breadboard

413

Chapter 33—Making Circuit Boards

414

Overview of Your Primary Circuit Board Options

414

Clean It First!

415

Making Permanent Circuits on Solder Breadboards

415

Using Point-to-Point Perforated Board Construction

416

Using Predrilled Stripboards

417

Creating Electronic Circuit Boards with PCB CAD

418

Producing Arduino-Specific Boards with Fritzing

420

On the Web: Etching Your Own Printed Circuit Board

421

Using Custom Prototyping Boards

422

Making Semipermanent Circuits with Wire Wrapping

422

Effective Use of Plug-in Headers

424

Part 6—Computers and Electronic Control
Chapter 34—An Overview of Robot “Brains”

425

Brains for the Brawn

427

Igor, Pull the Switch!

428

Brains from Discrete Components

428

Programmed Brains

429

Of Inputs and Outputs

434

Chapter 35—Understanding Microcontrollers
All about Microcontroller Categories

437

437

Microcontroller Shapes and Sizes

440

Under the Hood of the Typical Microcontroller Chip

441

Microcontroller Programmers

444

All about Microcontroller Speed

445

Chapter 36—Programming Concepts: The Fundamentals

446

Important Programming Concepts

446

Understanding Data Types

450

Lucky Seven Most Common Programming Statements

452

Variables, Expressions, and Operators

455

On the Web: More Programming Fundamentals

459


xvi

CONTENTS

Part 7—Microcontroller Brains
Chapter 37—Using the Arduino

463

Arduino under the Hood

463

Many Variations on a Theme

464

Ready Expansion via Shields

465

USB Connection and Power

466

Arduino Pin Mapping

467

Programming the Arduino

467

Programming for Robots

469

Using Servos

473

Creating Your Own Functions

474

On the Web: Operating Two Servos

475

Flow Control Structures

476

Using the Serial Monitor Window

477

Some Common Robotic Functions

478

Using Switches and Other Digital Inputs

479

Interfacing to DC Motors

479

Chapter 38—Using the PICAXE

482

Understanding the PICAXE Family

482

Programming the PICAXE

487

Core Language Syntax

488

PICAXE Functions for Robotics

492

Example: Controlling an RC Servo with the PICAXE

493

Example: Reading Buttons and Controlling Outputs

494

Chapter 39—Using the BASIC Stamp

496

Inside the BASIC Stamp

496

Stamp Alone or Developer’s Kit

498

Physical Layout of the BS2

498

Hooking Up: Connecting the BASIC Stamp to a PC

499

Understanding and Using PBasic

500

Interfacing Switches and Other Digital Inputs

506

Interfacing DC Motors to the BASIC Stamp

507

Interfacing RC Servo Motors to the BASIC Stamp

508

Additions in PBasic 2.5

509

CONTENTS

Chapter 40—Interfacing Hardware with Your
Microcontroller or Computer

xvii

512

Sensors as Inputs

512

Motors and Other Outputs

514

Input and Output Architectures

516

Interfacing Outputs

519

Interfacing Digital Inputs

520

Interfacing Analog Input

522

Connecting with USB

525

Using Analog-to-Digital Conversion

526

Using Digital-to-Analog Conversion

527

Expanding Available I/O Lines

528

Understanding Port Changing

531

On the Web: Understanding Bitwise Port Programming

533

Chapter 41—Remote Control Systems

534

Build a Joystick “Teaching Pendant”

534

Commanding a Robot with Infrared Remote Control

537

On the Web: Control by Radio Signal

543

Broadcasting Video

543

Part 8—Sensors, Navigation, and Feedback
Chapter 42—Adding the Sense of Touch

547

Understanding Touch

547

Mechanical Switch

548

Using a Button Debounce Circuit

555

Debouncing Switches in Software

556

Programming for Bumper Contacts

557

Mechanical Pressure Sensors

558

Experimenting with Piezoelectric Touch Sensors

563

Experimenting with Piezo Film

565

On the Web: Build a Piezo Bumper Bar

568

Other Types of “Touch” Sensors

568

Chapter 43—Proximity and Distance Sensing

570

Design Overview

570

Simple Infrared Light Proximity Sensor

572


xviii

CONTENTS

Modulated Infrared Proximity Detector

574

Infrared Distance Measurement

580

On the Web: Passive Infrared Detection

585

Ultrasonic Distance Measurement

585

Chapter 44—Robotic Eyes

590

Simple Sensors for Robotic Eyes

590

Building a One-Cell Cyclops Eye

594

Building a Multiple-Cell Robotic Eye

596

Using Lenses and Filters with Light-Sensitive Sensors

600

Video Vision Systems: An Introduction

600

Chapter 45—Navigating Your Robot

603

Tracing a Predefined Path: Line Following

603

Wall Following

608

Odometry: Calculating Your Robot’s Distance of Travel

609

Compass Bearings

617

Experimenting with Tilt and Gravity Sensors

619

More Navigational Systems for Robots

624

Chapter 46—Making and Listening to Sound
Preprogrammed Sound Modules

625
625

Commercial Electronic Sound Effects Kits

627

Making Sirens and Other Warning Sounds

627

Using a Microcontroller to Produce Sound and Music

628

Using Audio Amplifiers

630

Sound and Music Playback with a Microcontroller

631

Speech Synthesis: Getting Your Robot to Talk

632

Listening for Sound

634

On the Web: More Sound Projects

637

Chapter 47—Interacting with Your Creation

639

Using LEDs and LED Displays for Feedback

639

Feedback via Simple Sounds

646

Using LCD Panels

646

Robot-Human Interaction with Lighting Effects

649

Chapter 48—Danger, Will Robinson!

655

Flame Detection

655

Smoke Detection

657


CONTENTS

xix

Detecting Dangerous Gas

661

Heat Sensing

664

Robotic Firefighting Contests

665

Finally, Go Out and Do!

665

Appendix A—RBB Online Support

You’ll Find . . .

667
667

Backup Support Site

668

Sources for Special Parts, Web Sites

668

Appendix B—Internet Parts Sources

669

Robotics

669

Electronics

670

Hobby

670

Forums and Blogs

671

More on the Web!

671

Appendix C—Mechanical Reference

672

Decimal Fractions

672

Drill Bit and Tap Sizes—Imperial

673

Drill Bit and Tap Sizes—Metric

674

Numbered and Fractional Inch Drill Bit Comparison

675

Fasteners: Standard (Imperial) Threads at a Glance

675

Comparison of Decimal Inch, Fractional Inch, Mil, and Gauge

676

More on the Web!

676

Appendix D—Electronic Reference
Formulas

677
677

Abbreviations

679

Letter Symbols Used in Electronics

681

Numbering Units in Electronics

681

The Six Most Common Units of Measure in Electronics

682

Resistor Color Coding

683

Wire Gauge

684

Index

685


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ACKNOWLEDGMENTS

Once more I’ve climbed the mountain. And once more I look back to those who have helped
me turn my vision into reality.
To my friends at the San Diego robotics group; to John Boisvert and his amazing robotics
emporium; to Mike Keesling, Alex Brown, and Tony Ellis; to those I’ve met over the years on
the comp.robotics.misc newsgroup for their great ideas, wisdom, support, and advice; and to
Frits Lyneborg and the entire LetsMakeRobots.com community;
To Russell Cameron, roboteer extraordinaire, and to Jan Malasek of Pololu, Mario Tremblay of Robotshop, Clive Seager of Revolution Education, Jim Frye of Lynxmotion, Nathan
Seidle of SparkFun, Gerry Coe of Devantech, and Claudia and the crew at DAGU;
To the makers and keepers of the Arduino, PICAXE, BASIC Stamp, FIRST CAD Library,
and Fritzing for great tools, great software, and great art;
To Judy Bass and the editors at McGraw-Hill, who’ve put up with me all these years; to my

agents at Waterside Productions; and to Bill Gladstone who first helped me take on this project way back in 1985 (how time flies!);
And last but certainly not least, to my wife, Jennifer.
I offer my heartfelt thanks, one and all.

xxi


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PHOTO AND
ILLUSTRATION CREDITS

Adafruit Industries (www.adafruit.com): Figures 37-2, 37-3, 37-10
Christopher Schantz (www.expressionimage.com): Figure 2-14
Cooper Industries (www.cooperhandtools.com): Figure 30-4
Devantech (www.robot-electronics.co.uk).: Figure 48-2
General Electric: Figure 2-4
Hitec RCD (www.hitecrcd.com): Figure 23-1
Lynxmotion (www.lynxmotion.com): Figures 1-1, 2-6, 2-7, 20-10, 27-2, 28-13
iRobot Corporation (www.irobot.com): Figures 1-6, 2-3
Maxbotics Inc (www.maxbotics.com): Figure 43-14
Miga Motor Company (www.migamotors.com): Figure 25-7
Parallax Inc (www.parallax.com): Figures 2-10, 34-2, 39-1, 43-3, 48-6
Pitsco Education (www.pitsco.com): Figures 1-7
RoboRealm (www.roborealm.com): Figure 44-12
Pololu (www.pololu.com): Figures 10-4, 10-7, 45-5, 45-19
Russell Cameron/DAGU Hi-Tech Electronic: Figures 1-1, 44-10
Scott Edwards Electronics (www.seetron.com): Figure 27-6
SparkFun Electronics (www.sparkfun.com): Figures 42-14, 46-7, 46-9, 46-10

The author expresses his deepest gratitude for the use of 3D CAD objects developed by Ed
Sparks at FirstCadLibrary.com; to the developers and contributors of the Fritzing project
(www.fritzing.org); for public domain art developed by Wikipedia user Inductiveload, and others; and to the talented artists of the 3D models used throughout this book.
This publication contains images used under license from Corel Corporation, Hemera
Technologies, Shutterstock.com, and other licensors.

xxiii


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