Grin and Bear It
I’ve been seeing a lot of complaining lately about the state of the engineering profession in your letter section. Readers talk about the lack of jobs, respect, and money. Some of your readers think engineering needs more regulation so engineers can command the same dollars as lawyers, for instance. I would love to see how much the average product designed in the U.S. would cost if engineers were paid $350/hr as one of your readers suggested. In turn, it would be humorous to see how quickly most U.S. design would be outsourced, along with the manufacturing, if design was that expensive.
With regards to recruiting more engineers and improving the pay scale, I don’t think we need to do anything. As more students shy away from engineering and engineers become harder to find, the pay scale will go up. Did you ever wonder why schoolteachers who arguably have as important a job as a surgeon make a fraction of what a medical professional makes? It’s called scarcity. If the degree program is harder to get through and qualified job candidates are harder to find, then pay will go up. It’s not rocket science. We don’t need to artificially regulate pay scales by licensing engineers, the coursework is difficult enough.
PE certification is not the answer as most companies don’t have PEs for new grads to study under. And we certainly don’t need to encourage high-school students to enroll in programs they are not already passionate about. The high levels of attrition in engineering programs will only serve to improve the pay scale and the quality of the eventual graduates. Let supply and demand take care of the problem. While I understand that it would be wonderful to have piles of cash and the adoration of our friends and neighbor, perhaps we should be telling our children to pick a career they will enjoy instead of encouraging them to chase the jobs that makes the most money. If we all chose our career path based on salary, who would be teaching our children and designing the next great product, for that matter?
Playing the devil’s advocate, I would say the reason medical professionals make more than teachers is not a natural scarcity but an artificial one. There are far more applicants to medical schools than ever get accepted, and the ones who are rejected are not all dolts. The medical profession has chosen to restrict the number of medical schools, some would say to keep salaries up.
And interestingly enough, if news reports are to be believed, those policies have contributed to a rising number of people traveling to foreign countries for elective surgery where prices are lower. Leland Teschler
Bobbie Panelli’s letter to the editor (May 22) issue really struck me as odd. I got into engineering because it’s a cool profession and I like doing it. It has always been a part of me from Tinker Toys and Legos to linkages and bearings. I did not get into it for political clout and fame or to become a millionaire.
The last thing the industry needs is licensing bodies like those for lawyers and doctors. Think about it. Do we really want to be as socially reviled and feared as lawyers? And do we want to be like doctors, constantly looking over our shoulder for those feared and reviled lawyers? I am happy to work “behind the scenes” to make the world turn. Yes, the corporations get the rights to the stuff we make; let them. Let other people deal with the headaches and legal mumbo-jumbo of figuring out who gets to make my product and fleece the people who are making something kinda-sorta like it.
I am also perfectly happy with ASME and such. They give me standards that take the guess work out of a lot of things. That’s what we need. We don’t need some Nanny Society dictating our every move, bullying us and everyone else about every single aspect of our jobs and telling us where and when we can and can’t practice. No, we usually aren’t rich, but I make enough to take care of my family and have a few toys here and there. No, most of us are not famous, but the people who are important to me all think my job is cool. And no we don’t have a lot of political clout, but why would we want it?
Joel W. Suffridge
The article on linear motors (“How to apply direct-drive servomotors,” May 8) has a dangerously incorrect equation for RMS force (on page 96). There is an extra “2” in the denominator of the rms equation. If any readers use this equation as gospel and sizes a motor with it, the motor will be 40% too small on its continuous rating.
The equation is actually correct as shown, but thank you for pointing out an area that needs clarification. The summation of the four time periods of 0.033, 0.033, 0.033, and 0.1 represents travel time in only one direction. In the example, the same time profile is used for travel in both directions. Because of the slope, the forces applied when moving up the slope differ from those moving down. For the overall RMS value, the summation of time multiplied by the force squared (t ft″) for each segment of the profile has to look at both directions. Therefore, the summation of the time profile for a single direction must be multiplied by two to handle motion in both directions. The author of the design guide I used as reference for the article took this shortcut in the calculation and that led to the confusion. I should have made it more clear that the summation of t in the denominator represents travel in only one direction.
Getting rid of the two as you suggest is more correct, however. Not only does it handle this example, it also handles the possibility of different time profiles for each direction. Then the summation of t in the denominator would show eight different time periods (two for acceleration, travel, deceleration, and stop) needed for both directions of travel and the 2 factor is not needed. It’s the diligence of readers like you that keeps us on our toes here at Machine Design, and we wouldn’t have it any other way. Robert Repas
Who’s Minding the Store?
Your last issue’s news (“High-tech jobs slowing but still growing,” May 8) included the statement that “Seven of nine tech-manufacturing sectors lost jobs in 2007”. In the same article, the head of a tech trade association (obviously representing manufacturers) stated that we risk losing competitiveness due to a “failure to let the best and brightest from around the world work in the U.S.” Let me see if I understand: The same manufacturers who have sold out U.S. manufacturing and its associated technical jobs to low-cost countries are now complaining they don’t have enough lowerwage foreigners in this country on H-1B visas to complete the task of removing the last job opportunities from U.S. engineers and techprofessionals? Forgive me if I can’t afford to offer them any Kleenex due to budget cuts.
Concerning your article on diaphragm seals (“Diaphragm seals for pressure sensors,” April 10), were you aware there is an ASME standard for diaphragm seals? The standard is ASME B40.2 and is contained in the pressure measurement standard ASME B40.100.
Robert Wakeman, ASME B40