Pretty models must be backed up by the math

Daxon Engineering Inc. Chief Engineer Matthew Loew's comments on a recent article in MACHINE DESIGN on changes in engineering over the last 80 years prompted several interesting reader responses:

 Design Engineer Dennis R. Boulais writes, "The problem is that organizations don’t want to wait for engineering systems design to be done. They want to see “progress” and they want to see it now! The fact that the pretty models should be backed up by the math to base them on, it BORING to most management. They don’t want to see systems anaylisis, look at it or hear about it. And don’t even think about what goes on in today’s cross-functional project development teams. The participants have neither the training, patience or the interest to follow a systems development effort. They CAN follow colored graphs and pretty pictures. Remember, lots of pretty models = project progress to these people. The sad thing is that I have seen more and more try till it works efforts in the last 40 years. It’s been getting worst for a long time now and we will never see it get better."

And Jim Tuttle of Texas International Oilfield Tools Inc. responds, "A good, thoughtful article. I particularly liked 'Let's not get lazy with engineering just because we can make good looking designs in CAD early and can quickly make colorful stress plots in FEA. I'd like to see a marriage of the traditional approach that harnesses the best of engineering expertise and the use of engineering fundamentals with the power of the tools we have at our disposal.' For me, the modeling is nothing more than an accurate 3D sketch pad. Back in the 70s when I did design using a drafting board, I didn't use engineering fundamentals any more than I do today. I ALWAYS veriify my designs "on paper" as well as using the new whiz bang tools. Having seen FEA yield results that were way off from reality, I take them with a grain of salt. Using modeling is a little slower than "back of the envelope", but if you build your models with an eye to easy modification, the net time is less. Plus, I can download component models from many sources and save the time of doing them myself. Your certainly right, though - modeled and simulated certainly does not mean a good design."

Also, Garry Edson says, "I was taught by an wise old man who came out of Europe before the war. He was trained starting at the age of 8 in all of the trades. Once he completed his training in the trades, they allowed him to go to engineering school. Now having said that! If he gave you a print and said that the run of pipe from x to y was 20'6 1/2" then the pipe was in fact that long. How did he know that with out having the modern tools we have today. Because he could do the job as well as the best fitter, millwright or what ever trades person you had there. We do not teach they way we use to. Maybe not a good thing, but some say we do have better tools to work with, so does it matter. I see so many young people who want to be at the top of the game right out of school. The sad thing is to see that they know nothing and can not except the fact that they don't. Shame on or system, before I could carry a wrench (one year) as an apprentice millwright. I cleaned, chased, wipe, held, and was over all lower then a snakes belly. But, I learned and learned well. We need to get back to (new favorite term these days) old School teaching before we move ahead to the new stuff. My point is that molding was a good way to see if the idea you had was up to snuff. Sure cad is a great tool, but only a tool. Nothing beats knowledge in the physical sense. Any good engineer who puts in some time with a 'A' rate millwright could learn more in 6 months then a year at a school (might have to carry my tools and clean some grease though). Good article."

What do YOU think? Please drop us a line