Motion System Design

When all else fails — Part 2

Over the course of their careers, most engineers adopt somewhat of a routine or systematic method for solving problems. This standard procedure works under most circumstances — but not all. In fact, in such cases, the approach engrained in engineers’ minds can actually be an impediment, preventing the discovery of a solution or method that works.

It is for this reason that engineers need a wild goose or two in their bag of tricks; something to lead them off the beaten path. Last month, we considered three such strategies. Here are several more with the potential to steer you away from the limitations of conventional thinking.

Try something old — When business groups meet to conceive ideas, it’s generally accepted that the goal is to come up with something new. Anyone who suggests otherwise — ‘hey, let’s think of something old’ — would be laughed out of the room. Not only is it presumptuous to think all good ideas are new, it’s a setback to progress. People had some very good ideas in the past, as the following example reveals.

In 2001, a group of Norwegians celebrated the opening of a pedestrian bridge about 20 miles south of Oslo. As cranes lifted a 48,000-sq-ft white cloth, the graceful structure came into view, some 500 years after Leonardo da Vinci first sketched it.

Da Vinci designed the span to cross the Golden Horn inlet in Istanbul. Critics said it couldn’t be built, convincing the sultan who funded the work to scrap the project. Although initial plans called for stone, the Norwegians used wood to save money. The architect, however, claims the bridge can be built in wood or stone, to any scale, because it’s based on sound design principles. There’s no telling how many other brilliant ideas are languishing on the dusty shelves of time, waiting for someone to discover them and tap the ingenuity from days gone by.

Get perturbed — Insanity, according to one definition, is repeatedly doing the same thing and expecting a different outcome. In the systematic world of engineering — where designers are fenced in by catalog solutions and a management philosophy with all the originality of a recipe card — it’s fairly easy to get stuck in such a rut.

Computers face a similar trap when solving problems using numerical methods. Although they may arrive at a point where all equations seem to be satisfied, they have no way of knowing whether they’ve found a good solution, let alone the best. They can rerun the program 1,000 times, but each time they’ll come back to the same point. Programmers, of course, are aware of this and try to prevent it by perturbing the calculations, randomly changing data or the algorithm itself. Often, the computer will find a more optimum solution in the process of getting back on track.

There are many examples of a perturbing event having a positive effect on human effort. Take Charles Goodyear’s “accidental” discovery of vulcanized rubber. Goodyear had little money, so he did much of his research at home. One day, while experimenting with sulfur and rubber in his kitchen, he dropped some of the odorous mixture onto a hot cooking skillet. Instead of melting, as most people would have expected, the rubber hardened to a durable, leathery consistence; the rest is history.

The point here is when you run into a stone wall, get perturbed (make a few changes) and see what happens. Try different component types, sizes, or brands. Explore different configurations. Add or omit components. Vary your operating rates. Modify interfaces. The more radical the change, the better.

Buck the system — Some projects are doomed from the start. Suppose it’s 1985 and your boss tells you to design a daisywheel printer that’s ten times faster, quieter, and more affordable than anything on the market. You could spend months working on the problem, and fail. Or you could argue to use thermal, ink, or bubble-jet technology — or just go ahead and do it — and possibly succeed.

Thomas Edison, the epitome of a stubborn engineer, insisted on doing things his way throughout his career. In the case of the phonograph, his way was the only way. Edison was legally deaf. He judged his progress not with his ears, but with his teeth. He literally bit into his work, tapping into the mechanical vibrations rather than the sound they produced.

It would have been quite difficult for the great inventor to convince a typical “results-oriented” boss that a phonograph is first and foremost something you feel, and only secondarily, something you hear. More than likely, Edison’s argument would have been taken as an excuse for the scratchy, barely audible sound of the early prototypes. It probably would have earned him a spot in customer service or the unemployment line.

Edison had no choice but to optimize the right variable, vibration, while most people would have naturally keyed in on sound. He succeeded because he didn’t follow the conventional design approach. He couldn’t. And sometimes we need to realize we must do the same.

Larry Berardinis
[email protected]

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