Where is My Flying Car?

Charles D. Schultz

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

Latest posts by Charles D. Schultz (see all)


It was great fun reading news stories on the Back to the Future anniversary, and which inventions actually happened. Sorry, but a Hover Board just isn’t going to answer my transportation needs. It must be almost 50 years since The Jetsons debuted with flying cars, and we are still stuck in terrestrial traffic for hours.

No mention was made of Spacely Sprockets or Cogswell Cogs making parts for those flying cars, but I chuckle just thinking about two gear companies still being around in such a high-tech world. When I started in the trade, in 1971, people predicted hydraulics and electronics would make mechanical power transmission obsolete. Forty four years later, the gear business is very different — but still very necessary.

The gears we can make today are much better, of course, and there have been big changes in how they are used. The shift to front-wheel drive cars cut hypoid gear product dramatically. Few cars or trucks use worm gears in the steering mechanisms. Commercial gearboxes have leveraged high-capacity, surface-hardened gears to become much smaller and longer lasting.

Other than the occasional prototype or home-built experimental, there are no flying cars in regular use. Judging by the way people handle the expressways around Chicago, this is probably a good thing. It might take all the gear technology we have developed to get the fleet fuel economy numbers in the current regulations. The thought of seven- or eight-speed transmissions in passenger cars would once have seemed as far out as flying cars. No one in the 1970s would have predicted all those gears having ground flanks either.

Hopefully, somewhere in the world, little boys and little girls are still watching The Jetsons and dreaming of a day when they can fly to work or school. I have no doubt that our industry will be ready to make the necessary gears when the kids’ design is ready for prototyping.

Uncertain Times

Charles D. Schultz

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

Latest posts by Charles D. Schultz (see all)


While the news media is heralding improved job and income growth, people in gear manufacturing are worried about the security of their jobs. Low mineral prices, the drop in oil prices, political opposition to fracking and wind turbines, and gridlock on infrastructure repairs have hurt our biggest customers. One perfect example: A 100+ year tradition of large gear manufacturing is coming to an end in the United States with the sale of Rexnord’s foundry.

It isn’t just in the United States, either. Thanks to the Internet I am able to stay in contact with an engineer who previously worked for a consulting client in Western Australia. He is with his third employer since our original project began four years ago, and has endured several months of unemployment along the way.

This gentleman has my admiration for the positive attitude he has maintained throughout this experience. From the family photos and comments online, you never would have guessed he was stressed out. Perhaps it is a better social safety net or just having his priorities right.

When people talk about the 1950s as a Golden Age for the American worker, I can’t help but wonder what data they are looking at. My father was a factory worker who never missed a day of work — when he wasn’t laid off. He took whatever work was available to keep a roof over our heads, and often worked two jobs. It took a toll on a young father; sapped him of his strength and took away his hopes for the future.

There are a few employment gaps in my resume. I remember the sleepless nights, the worry, fear of the neighbors finding out. For those of you going through this now, or facing the possibility of unemployment in the near future, I pray that you’ll maintain your dedication to family and friends. Don’t try to be Superman. Talk to your spouse and family and friends. Network when you can. Develop a plan. Our industry will recover, and reliable people will always be in demand.

Most of all — put those worries aside when you interact with your kids — they are only this age once. To quote one of my favorite musicians, Paul Thorn: “Don’t let nobody rob you of your joy.”

Alumni Groups

Charles D. Schultz

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

Latest posts by Charles D. Schultz (see all)


I wrote last time about how the Internet has made it easier to reconnect with people you used to know. It has also been a boon to the formation of alumni groups for both schools and companies. Given the downsizing our industry has experienced, there are frequently more former employees than current employees.

Traditionally, alumni groups have preserved the traditions and “culture” of a school or military organization by holding reunions, attending “homecoming,” and connecting other alums with employment opportunities. Universities have long recognized the value of an enthusiastic alumni group.

Active companies might not see the value of former employees being part of a group. This is understandable but, in my view, rather shortsighted. I am eligible for several employer alumni groups and try to follow the University model on behavior, i.e. — if you can’t say something nice about the place/person, don’t say anything at all. When asked, I try to assist fellow alums make good career moves, but I don’t “recruit” the alumni ranks for third parties. When possible, it is my pleasure to send business opportunities to former employers.

A slightly different set of “rules” applies for alumni groups of companies that are no longer operating. I think it is a duty to keep these companies from being forgotten; just because they are no longer in business does not mean their ideas and products are without value. We lost some great organizations because of poor trade policies or financial fluctuations that were in no way their “fault.”

If you are an alum of one of those “ghost companies” you need to tout the things they did well, assist former customers in maintaining the legacy equipment, if you can, and, above all, celebrate the lessons you learned while working there. None of us became the people we are in a vacuum.

The Sage of the Sales Department

Charles D. Schultz

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

Latest posts by Charles D. Schultz (see all)


One of the great things about our Internet Age is the ability to reconnect with old friends and associates.  Apparently I have left quite a trail along the way, because my telephone and e-mail boxes frequently are contacted for information on past projects. Just this past week a customer from 26 years and three employers ago called looking for ideas on where his patterns and fixtures wound up. What followed was an enjoyable five or six minutes trying to remember the people and parts involved. No miracle revelation on the fate of his tooling, but I think he got pointed in the right direction.

Unfortunately, the guy who would literally have had the answer at his fingertips has long since left this earth. Andy Riccardi, our salesman for government accounts, had encyclopedic recall of every project he had ever bid on, and backed up by the most detailed 3 x 5 index card record system I ever saw outside of a public library. I sometimes teased him that the Russians might kidnap him for his ability to predict when the Department of Defense would next requisition certain spare parts. He was the rare salesman who tracked the projects he didn’t book, and was ballsy enough to call competitors to try to sell them leftover parts or raw material.

The advent of personal computers and the decline of analog instruments made Andy a dinosaur in 1989. Economic turbulence prevented proper recognition of his many contributions to the company’s previous success. Sales is a “what have you done for me lately” activity, and before we knew it, the markets Andy served so well disappeared. I appreciate the things I learned from him — particularly the importance of treating everyone, including competitors, with respect. Although his record keeping system was almost indecipherable, I admired his dedication to knowing every nuance of his field.

If your organization is fortunate enough to have an “Andy,” I recommend getting them to record a few stories for posterity. A Rosetta stone for their filing system would be nice too.

Microgeometry

Charles D. Schultz

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

Latest posts by Charles D. Schultz (see all)


Much of my design work involves “math modeling” gearsets to determine the lowest-cost components which will meet the requirements. Over the years, a designer develops his or her own set of guidelines for what geometry is acceptable and what is objectionable. A group of gear experts may agree on eighty percent of a design and argue for hours over the remaining twenty percent. This is particularly so in the area of “microgeometry” — lead and involute modifications that help improve performance at the extremes of loading.

Software packages include sub-routines to suggest values for these modifications. Unfortunately, microgeometry requires a very strong understanding of what loading conditions are. Many times we do not have adequate data to support the assumptions we have to make. Pushing buttons on software input is easy; modern grinders make it possible to produce whatever shape the program asks for.

Sadly, this mechanization can compound the problem. We once got FOUR different revisions to a lead chart during an eight-hour period. The machine’s operator could be forgiven for being slow to implement the second and third changes. The lesson we took away was to spend more time reviewing assumptions, and agreeing on them, before pushing the buttons for modification simulation.

Sometimes the charts just “don’t look right” to the experienced eye. If this happens on your project, don’t get angry. Instead take the time to review with the commentator why the assumed load conditions would result in the shape shown on the chart. If you can’t convince them, you might want to take another look at those assumptions.

The beauty of computer simulation is that you can consider many possible configurations in a short period of time without endangering the precious physical parts. The ugly side of computer simulation is that it is so easy to input faulty assumptions. The old adage — “garbage in, garbage out” — still applies. Spend the time needed to understand and verify load conditions before pushing those buttons.

Feedback and Comments

Charles D. Schultz

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

Latest posts by Charles D. Schultz (see all)


We are starting our second year of this blog and are pleased that it was named one of the Top 50 Design and Development Blogs on the Internet. Only #48 on that list but it is a big Internet and we are the only gear-oriented blog mentioned. Most of the credit belongs to the magazine’s searchable archives, in my opinion. The blog is just the gateway in.

Our initial hope was for the blog to feature an active comment stream. Unfortunately this plan has been ruined by spammers posting inane remarks with links to their scams. We have had a few legitimate comments that I will respond to here.

Matt Poulter asked about Stress Coat. When he Googled it, all that came up was an additive for tropical fish tanks. Now sold under the name StressKote (one word), Stress Coat was/is a brittle spray-on coating for use in testing castings and fabrications. Back in the Dark Ages, before Finite Element Analysis (FEA), we had to apply Stress Coat, load the part up statically, and “read” the cracks in coating to properly orient the strain gages. If you are doing development work scientifically, you still need to do these things in parallel to your FEA work. Without real-world modeling to back it up, FEA might be just pretty pictures.

Robert B. Price noted that he uses reverse engineering to replace damaged or missing parts on 1901-vintage motors. Many restorers and modelers face this challenge — the older the machine, the bigger the challenge becomes. As noted in earlier postings, gear geometry didn’t even standardize on the involute tooth form until 1921. Mr. Price’s motor could have had cycloidal teeth in any number of “systems.” To the casual observer, once the restored machine is up and running, the use of “modern” gears would hardly be noticeable. To an expert like Mr. Price, however, it would be an irritant worse than squeaky chalk in the lecture hall. Oh, wait a minute; some of you may not have ever suffered through an actual chalk-on-blackboard lecture. Perhaps a better analogy would be wearing an Alabama Crimson Tide sweatshirt with an Auburn University hat. It just doesn’t work for high-end restorations.

Both commenters raised topics that might merit further coverage in the blog or the magazine. If you have comments, please don’t let the spammers scare you off. We read all the comments and will respond in the blog. Editorial suggestions and contributions are best handled via e-mail. We enjoy hearing from you.

Trust, but Verify

Charles D. Schultz

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

Latest posts by Charles D. Schultz (see all)


Lest you come away from my last posting thinking I am completely trapped in the past, I’ve invested a fair amount in new software during the past few years, and have been trying hard to learn to use it. My “inner curmudgeon” has good reasons for being skeptical of change, so I have to do some things by both the old method and the new before completely letting go.

Sometimes my reluctance is informed by my own ‘horror stories” — as described in the previous blog. Other times it is based upon stories told to me by someone else. Our trade has a long memory, and it is important for those promoting “new things” to understand why certain “prejudices” are widely held.

Let’s start with some market sectors still skeptical of surface-hardened gears. It may come as a shock to those who have never built a device with “soft gears,” but few American suppliers offered carburized gears until the early 1990s. Europe fully embraced “hard gears” more than two decades earlier, and they saw the oil patch in particular as a market ready for change during the 1980 oil boom.

The classic “horse head” pump-jack gearbox had evolved into a commodity product with “soft” lower-quality herringbone gears and standardized interface dimensions. Converting to “hard” gears offered weight and cost savings; the resulting prototypes were way different from the existing drives. Where a herringbone box was the size of an office desk, the carburized box was the size of a suitcase — almost comic with big shaft extensions sticking out both sides. The rating calculations said it would work, and brave customers quickly put them into service — but not for long.

The horse head pump applies an impact load to the same teeth every cycle. The old herringbone units had the same durability rating as the carburized models, but the strength ratings were 50% higher. Teeth started popping off the “hard” gears within weeks of installation, and old oilfield hands have never again trusted “hard” gears.

Once the carburized gearboxes were redesigned to equal the herringbone strength ratings, they lost their cost advantage and much of the weight reduction. They are great pump-jack gearboxes, but still have to overcome those negative attitudes.

I would never want to go back to through-hardened gears; the advantages of modern, carburized designs are just too great when operating conditions are properly analyzed. As President Reagan was fond of saying: “Trust, but verify.”

Questioning New Techniques

Charles D. Schultz

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

Latest posts by Charles D. Schultz (see all)

In my last blog I mentioned the great analysis tools available to today’s gear engineers. On a current project, we are eagerly awaiting the finite element analysis (FEA) of a critical part that was designed using far less-sophisticated methods, going back 40 years.

It would be a great surprise if the FEA reveals any hidden flaws. Without going “full-curmudgeon” on you, I have been disappointed in FEA many times, beginning with the first FEA course ever offered at my engineering school, back in 1974. Our instructor, a newly credentialed PhD, brought FEA technology with him. It had been the topic of his dissertation and he was an evangelist for this method of stress analysis.

Unfortunately, the computers of the day were far less user-friendly. They weren’t as powerful, either; and between that, the dial-up/phone cradle interface and monochrome 10-inch monitors, the class struggled to get simple homework assignments done. We wondered if the box of punch cards the professor had brought from his previous school had been scrambled at baggage claim. By semester’s end, we barely managed to get a tri-axial stress on a cube to run.

My plan to impress the supervisors who were paying my tuition by using FEA on some fabricated steel housings went up in error messages. It was up to Stress-coat and hydraulic jacks to back up the manual calculations derived from Omar Blodgett’s classic book, “Design of Weldments.”

Fast-forward 20 years and computers were finally up to the task of analyzing a full housing — in color and on a big monitor. We couldn’t afford our own installation, of course, but an important project had the budget to sub-contract the FEA to the local experts. It was almost engineering porn to watch the colors change as the housing model was checked for various loading conditions. The only drawback was that the FEA work took so long that the patterns had to be revised twice to incorporate the results.

But even this “improved” FEA experience turned out to be a disappointment, as the housings were later found to be cracking in areas that FEA said were “very low stress.” The usual finger-pointing took place on whether the FEA, design, or foundry practices were to blame.

But I came away skeptical of any design based upon colorful pictures.

Hopefully this latest incarnation of FEA will convince me to fully embrace the 21st century.

Studying the State of the Art

Charles D. Schultz

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

Latest posts by Charles D. Schultz (see all)


A few years ago I presented a paper on reverse engineering at the AGMA Fall Technical Meeting. I heard through the grapevine that some folks were offended that “piracy” should be celebrated in such a prestigious forum. Reverse engineering is, and always has been, an important part of design engineering. In my opinion, to call it “piracy” is an insult to the great men and women who built the foundation of our trade.

While there are occasional instances where intellectual property rights have been violated, the majority of reverse engineering is done to keep old machines and process lines running. There is a huge amount of equipment for which parts and technical support simply does not exist in a timely manner. A sheet metal processing plant is not going to stop operating because an input shaft broke and the original equipment manufacturer wants 12 weeks to make a new one.

Another important aspect of reverse engineering is determining the “state of the art.” We are fortunate enough to live in a Golden Age of gear design. We have the machinery capable of routinely making parts which were once available only to front-line military equipment. Our computer capabilities are better than those that took us to the moon. Raw material quality and heat treat processing are better than ever. But if we don’t design our machines to fully utilize those capabilities we put our jobs, our companies, and our customers at risk.

When you consider the investments made to produce the material and equipment available, you have to be embarrassed when you make a crude or inelegant part. Every pound of material deserves to be made into a work of art; it is our job as designers and engineers to strive toward that goal. The first step, in my opinion, is to understand what is currently being done in your product area.

A side benefit to this situation is the pressure to make sure your own work will withstand study by your peers. There are no “gear cops” who will raid your plant for an aggressive interpretation of the rating formula, but your competitors will be happy to point it out to your customers. The American Gear Manufacturers Association was founded to rein in “outlaw” gear makers whose rating claims were putting the whole trade in a bad light. This “trust but verify” atmosphere has served our industry well because everyone benefits.

Do You Know Your Design DNA?

Design DNA

Charles D. Schultz

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

Latest posts by Charles D. Schultz (see all)


One of the things I enjoyed about the gearbox repair business was the opportunity to study the design strategies of so many different companies, both foreign and domestic. Products made five, ten, even thirty years apart would have many similar design features. This proves the power of “design DNA” — of adopting a set of design rules to insure quality, performance, and manufacturability.

Features like bolt circle combinations, seal configurations, and minimum numbers of teeth may not seem important to the non-designer,but selecting them in a vacuum can really slow you down. Design is a lot like commuting in that every time one driver makes a decision it impacts every other person on that route. Quality decisions take time; this is why having some decisions “pre-programmed” is so important.

Sadly, some people adopt a set of design rules without even realizing it; as in building it into their computer programs and forgetting about it. Others stick with rules that are made obsolete by changing technology.

If you aren’t sure about your company’s “DNA,” ask around; read the project notes on product development, and, if needed, reverse engineer your own product.

What if you don’t have “company DNA”? That is where learning from others comes in. AGMA offers some outstanding seminars by well-known consulting engineers. Every issue of Gear Technology contains important articles on how other engineers make design decisions. If you have decisions to make, the Gear Technology data base is fully searchable and available 24/7 — all over the world. Make your own reference binder; you’ll be happy you did.