Cheryl Shrock recently retired as Professor and Chairperson of Computer Aided Design at Orange Coast College in California, where she had taught since 1990. She is an Autodesk(R) registered author. Previous to teaching, she owned and operated a commercial product and machine design company, using CAD to create and document designs. This book draws upon both her teaching and industry experience. Steve Heather has 30-plus years of experience as a practicing mechanical engineer and has taught AutoCAD to engineering and architectural students at the college level. He is an authorized AutoCAD beta tester and a member of AutoCAD Connected Desktop Customer Council. Steve lives near Canterbury, England, and welcomes your questions or comments at: steve.heather@live.com.