June 14, 2022
[starbox] Much of my engineering practice is working with companies that design machines only once in a while. I enjoy working with the people on their staff and coaching them through the design and detailing process. One of their most common complaints is “Why is this stuff still so complicated?” As a gear industry “lifer” I have to admit that they have a point on some topics. I do remind them of Albert Einstein’s famous comment that “Things should be as simple as possible, but no simpler.” There is a huge risk in “dumbing down” some topics; we argue about this frequently in standards work. Many people want the standards stripped of any “educational” content on the grounds that if the reader doesn’t understand the equations presented, they are not qualified to solve them. I come done on the opposite side of that argument, although I am willing to put the instructional stuff in the appendix or a separate information sheet. In the course of researching the history of gear ratings, for example, the “back story” is as important as the mathematics. It is in the “extraneous” comments that you find out what the authors “didn’t know” at the time and this helps in evaluating what may change in the future. But back to my clients’ complaints. The most recent example concerned involute splines. One needed help working through the very complex DIN 5480 for metric splines. If ever something needed an “Idiot’s Guide to…” it is DIN 5480! Not a single selection has “standard dimensions” as taught in engineering school. That dastardly “rack offset coefficient” is everywhere. Without a doubt the most pirated standard on the Internet just out of necessity — if you can’t find the right reference chart you will be tearing your hair out for days. Contrast that to ANSI B92.1; still complicated with multiple fit classes, root fillet configurations, and ways of locating internal to external, but chock full of instructional information. Still tough to use for the novice, however. No rack offset coefficient is needed to confuse them when you have “actual” and “effective” measurements to understand. The reference tables concern pin measures, but people have trouble deciding how to obtain the other “limit” on that value to put on their drawings. I suppose I should be happy that this complexity fills my e-mail inbox but I have always believed a good standard should be useable without an expert’s assistance. What do you think? What standards need to be improved?