Don’t Forget the Follow-Up!

One of the cardinal rules of design engineering is that you will never overcome physics. It is an applied science so misunderstanding or ignoring material properties, statics, dynamics, thermodynamics, or lubrication basics will bite you when you least expect it. Sometimes the “lesson” is immediate; other times it waits a bit before making the flaw known.

How do I know this? When you undertake as many projects as I have you learn the hard way and those lessons stick with you. It is far less painful to learn from the mistakes other people have made; our gearbox rebuilding business provided wonderful insight into the design practices of many competitors along with the problems those practices frequently caused. A good portion of my personal design rules came from things observed repairing, rebuilding, and upgrading gearboxes that failed in the field.

No designer should be shielded from their mistakes. Physics is a brutally honest instructor. It does not care how many degrees you have. It does not grade on a curve. It will also apply the forces it sees fit, not limiting them to what you thought they were. One of the biggest roadblocks to wind turbine adoption, for example, has been a misunderstanding of the actual load conditions. This “ignorance” was compounded by pressure to move from prototype to production quickly and to scale–up designs that seemed to have initial success. By the time the cracked housings or gears were discovered, many similar units were already in service which were doomed to suffer the same fate.

It was almost better to have “teething” problems than to get those damning phone calls just before the warranty ran out. [Not that receiving a call from the customer’s chief engineer from the base of a tower screaming about the rain of M36 bolt heads could ever be forgotten. Physics does not overlook faulty hydrogen embrittlement relief no matter what the certificate of compliance says.] If you catch a problem early enough you can implement a “fix” before the damage spreads and the bill grows.

You may even avoid getting a failure analysis paper published by some consulting engineer looking to make a name for themselves. Gear Technology, fortunately, only publishes peer reviewed papers from respected power transmission technical conferences. Imagine the burning ears of all the automotive engineers from the thousands of Internet chat rooms devoted to their vilification!

Do yourself and your team a big favor: test your products thoroughly, be brutally honest about areas for improvement, and encourage your customers and end users to keep in touch. When the opportunity arises to visit field installations, take it. Unless, of course, it involves going into outer space; the expense reports would be impossible to slip by accounting.

About Charles D. Schultz 678 Articles
Charles D. Schultz is President of Beyta Gear Service and one of Gear Technology's technical editors.