Title: Building Robot Drive Trains
Authors: Denniis Clark and Michael Owings
ISBN: 0071408509
Price: $25 US

Any 10-year old Lego Mindstorms engineer can tell you it is not always easy to get your bot to go where you want it. In Building Robot Drive Trains, authors Dennis Clark and Michael Owings provide an introduction to building motor controllers and simple drive train systems to help you get that bot where you need it.

Here's how the chapters play out:

  • Chapter 1: The Basics of Robot Locomotion
  • Chapter 2: Motor Types: An Overview
  • Chapter 3: Using DC Motors
  • Chapter 4: Using RC Servo Motors
  • Chapter 5: Using Stepper Motors
  • Chapter 6: Mounting Motors
  • Chapter 7: Motor Control 101, The Basics
  • Chapter 8: Motor Control 201 – Closing the Loop with Feedback
  • Chapter 9: Electronics and Microcontroller Interfacing
  • Chapter 10: Wheels and Tank Tracks
  • Chapter 11: Locomotion for Multipods
  • Appendix A: Glossary
  • Appendix B: Tables, Formulae, an Constants
  • Appendix C: Resources
  • Index

The authors seem to struggle with just who their audience is. At times the text turns academic delving into various math and physics forumulas in an attempt to answer questions like how powerful a motor to use. Yet these sections tend to leave a lot of work to the reader, stopping short of tying the theory to practical implementation strategies. I eagerly worked the math for three pages trying to better understand my robot's motor needs only to come up with a number and no explanation of what it really means in practical terms.

Then at other times, the academic discussion gives way to spot-on advice that is obviously coming from someone who has been there, done that. Take the section in Chapter 8 on shaft encoders – you get far more discussion here than I've seen in any other text and it isn't just a bunch of math, but detailed information you can put right to work. There are numerous patters shown – patterns you could actually scan, enlarge and use on a project. This section alone is worth twice the price of the book.

There are a few places where I was looking for more detail, such as Chapter 5 where they describe stepper motor controllers and driver circuits. The tables detailing step patterns are useful as is the description of how the stepper actually works. The discussion around figuring out how to wire a surplus stepper with little or no documentation is excellent, once again you hear the voice of experience coming through loud and clear. It took me several hours of experimenting to get a stepper controller working and I ended up having to use other books and Internet resources. However, the information here did help me know what to go look for. And in the end, the tables for stepper patterns helped me to finally get my motor working.

The chapters dealing with mechanical linkages and things like how to physically mount your motors are useful to the newcomer, but may fail to satisfy advanced readers. If you have some basic machining skills and equipment, you probably can make motor mounts and shaft couplers as good as any you will find here.

The book stops short of providing information about how to make u-joints, CV joints, transmissions or gearboxes, and other mechanical devices you might need if you are building an all-wheel drive with a single motor or if you are just trying to build an outdoor robot with a suspension system. These are more advanced topics, but with “Drive Trains” in the title, a reader might expect them to be covered. In Chapter 11 they talk about steering mechanisms briefly, but again do not provide sufficient details for an amature to build something from.

I highly recommend the book. There is something for everyone. If you are building a serious robot, this isn't the only book you will want, but I think you will find it very useful. I hope the authors come back for a second edition and I'll certianly purchase a copy if they do. If I had just one recommendation for a second edition it would be to give the reader a practical example with each of the formula's – help me understand how to apply the math to a real-world problem. And if I could offer a second recommendation, I would like to see more advanced information on suspension systems, building gearboxes, drive shafts, u-joints and other associated drive train components.