You kids are spoiled! Back in my day it took at least a day to see the results of computer modeling, longer if the courier dropped the box of input cards or you had them in the incorrect order. Even entry level gear rating software produce reports in mere seconds and higher cost packages provide direct links to 3-D CAD packages that will turn those reports into pretty colored renderings. I am letting my inner curmudgeon out for this blog to make a point first espoused by legendary gear engineer Don McVittie: beware of what that box on your desk tells you. Just because it provides a professional looking report does not mean it is correct. It has been tempting, during this year long foray into gearing fundamentals, to share my own personal “rules of thumb” for gear design. To do so would just be substituting one set of outdated instructions for another. Each designer has his or her own set of problems to resolve and a generic guidebook is not going to work. Each of you has to develop a complete understanding of the software you have access to. There is no shortcut to running problem sets, reviewing the results, modifying the input, and running the program again. Modern software allows you to refine designs very quickly after reviewing a wide range of solutions. There is no excuse for sloppy and inefficient gear designs. Minor changes can provide big improvements in load capacity and service life. Just using rack offset can increase rated capacity by as much as 10% over “standard geometry.” A 2.5% increase in center distance can double that improvement. No real increase in part cost either. Our goal at Gear Technology is to help you build the best performing and most cost effective products possible. We work diligently to provide content that covers emerging methodology on a variety of gear types. You will get more out of these articles if you have a good understanding of how your own design process works.