The magazine is celebrating its 30th anniversary this year and many special features will be published about technological breakthroughs that occurred during that time. I’ve been a subscriber from the first issue and look forward to having my memory jogged with the next few issues.
One of my favorite features in the early years was the sequence of Leonardo Da Vinci sketches on the cover. The artist/engineer/inventor was way ahead of his time in many areas and has inspired several books, movies, and television shows. (Indeed, if Hollywood, Cable TV and the New York Times Best Seller List are any indication, he’s hotter than ever.) Only now can some of his inventions be made operational.
Research into gear technology at the turn of the previous century revealed that all of the manufacturing methods we currently enjoy were already in use. The machines were slower and less accurate. The tooling was softer and less capable. Even slide rules weren’t readily available until the 1880s.
Yes, they were grinding gears in 1900 — by several different methods, too. The logo of the Citroen automobile company is a reflection of the herringbone gear type the firm pioneered. As mentioned here in previous blogs, there were many different tooth forms in use. It was a time of great experimentation in all forms of mechanics. Not everything worked, of course. The tools and materials were often not up to the task. We see this most frequently today in measuring instruments, but our predecessors had little need to measure in microns when the process capability was in thousandths.
The Auburn-Cord-Duesenberg Museum in Auburn, Indiana has preserved a 1930s design studio complete with clay models and an analog coordinate measuring machine (CMM) that was used to develop full-scale car bodies. Beautiful boat tail speedsters were sketched, modeled in clay, and scaled up to full size using a device made from scraps of wood and sections of dowels. It functioned like a modern CMM, but required someone to write down the results and proportion them to “full size” — a clever, low-tech solution to a problem that vexed designers for years. A friend used a homemade version of the device to scale up a model car; he had a commission to construct a version large enough to mount on an adult go-kart and the 1930s technology did not let him down.
I fully expect to see more of Leonardo’s inventions brought to life in the years ahead. Great ideas are timeless. Some are only awaiting our ability to implement them.
I belong to a number of online technical forums besides contributing to the occasional “Ask the Expert” column here at Gear Technology. Lately I have noticed a disturbing (at least to me) trend of questioners just wanting to be directed to an app or given the specific answer, rather than wade through an explanation or a reference book/paper. At the risk of sounding like a curmudgeon — or your old math teacher — sometimes you have to experience the trials of the journey to appreciate the wonders of the destination. To be perfectly blunt — there should be no helicopter rides to the mountain top.
Early on I posted about the dangers of using computer software without understanding what was going on inside that “black box.” I am not saying everyone needs to write their own code; just that you have to understand the process and the influence factors before you can really know the answer provided is what you are looking for.
The incident that inspired this particular rant concerned microgeometry modifications. I have no idea what kind of gears the inquirer was working on. The loads and duty cycle were as unknown to me as were his part quality. My friend Ray Drago (www.gear-doc.com) says the best answer for a consulting engineer always begins with “It depends.”
So I guess “it depends” upon whether you want to understand why you are doing something, or just want to put numbers down on the drawing. I appreciate the pressure of deadlines and the desire to impress a supervisor, but over the span of a career you will never regret the time spent studying good references.
Shortcuts are tempting, but often result in “answers” that don’t fit your particular problem. Going on a journey involves certain risks. So does copying answers without understanding how they were arrived at.
The gear world needs more mountain climbers and fewer helicopter passengers.
Over the years, some of the luster has come off the Indianapolis 500, but it remains a major cultural influence. I caught the racing bug as a kid growing up in Milwaukee, and looked forward to the start of practice at the Brickyard much more than the baseball opener. And given what we do for a living, I have since learned that many of my friends in the gear trade feel the same way.
During the 1960s there were no specified chassis or crate motors; each May was a motorized science experiment in front of the cameras and large crowds. There were some wild cars that bombed; remember the Smokey Yunick “Sidecar Offy” with the driver positioned out in a pod? Or the twin engine Porsche car? There were other radical vehicles that came ever so close to changing the course of racing history. What if the STP turbine car’s $6 ball bearing hadn’t failed? Or the Novi’s tremendous power had somehow been tamed?
There was always something to be learned from these “experiments.” For example: hard work sometimes paid off for small-budget teams; organizations with great histories and big budgets sometimes couldn’t even make “the show;” technical overreach could explode before a worldwide audience; careful reading of the rules could pay off (that infamous, one-year-only, push-rod Mercedes-Benz) — or be slapped down in court; and refusal to settle for less than perfection produced some cars that can only be classified as “jewelry on wheels.”
So what does any of this have to do with gears?
True, only rarely have gears themselves figured into the larger drama on the track. But good engineering practices were on display and the event made mechanical design front page news.
Count me as one of those kids with his face pressed against the fence who was inspired to a career in engineering because of the Indy 500.
This week’s Helical Gear Rating Committee meetings included a much hoped for improvement: a new member! Not only that, a new member under 40 years old. I won’t embarrass this young engineer by mentioning his name, but I thank his employer on behalf of the committee for sending us a new recruit.
Although “Engineer X” has a good bit of experience in the trade, he left a big company with lots of support structures for a smaller firm. There is no longer a gear summary expert or a hobbing specialist. He no longer has access to a huge engineering library, either.
We had an enjoyable conversation over lunch advising him on which books he should buy, to have available in the future. As mentioned previously on this blog, I have a suggested bibliography listed in my book, An Introduction to Gear Design, which is available for free download at www.Beytagear.com.
Unfortunately, many of the great gear books are out of print. Let’s face it — the market for technical books is rather small and probably getting smaller. I was thrilled to discover through Amazon that some publishing-on-demand vendors will provide “obsolete” titles if they have been scanned into a library somewhere. I hope our young friend is able to track down used copies or get new ones made up.
Over the years, I have become very protective of my personal library, as a few treasured volumes were never returned after being lent out. Online archives for technical magazines such as Gear Technology can never quite replace the feeling of a familiar book in your hands.
That said, no one else in my family shares my affection for gear books. We go to enough estate sales to realize my precious references may end up in a landfill if I don’t recruit their next caretaker. That is a worry for another day, as retirement is many years in the future for me.
What reference book would you recommend to our new committee member?
I began this blog with an appeal for abstracts for the 2014 AGMA Fall Technical Meeting. For those of you who had an abstract accepted, this is a gentle reminder that your final draft is due May 15th. Based on previous experience, I forced myself to complete this year’s paper a bit early. Not to gloat, but the formatted version is already at AGMA headquarters and ready for peer review.
The peer review process has been in place for many years as an aid to both the association and the authors. AGMA and its members are protected from overly commercial or technically inaccurate presentations. The author(s) get a couple of experienced sets of eyes on their paper — eyes that can catch those copy gremlins, grammatical errors, and miss-marked graphs.
The reviewers are volunteers from the AGMA ranks, many of whom have presented papers at past meetings. It is similar to the assignments given technical editors here at Gear Technology; the reviewers look for things that might lead to misunderstanding amongst the audience and some reviewers can be rather direct in their criticism.
You don’t submit a paper for peer review if you have a thin skin. This is my fourth time through the gauntlet and not every review has been completely positive. Some questioned my choice of topics and one didn’t think reverse engineering should be mentioned in a public meeting — much less be the topic of a paper. I am happy to say the audience disagreed. That paper was very popular and caused much discussion, as I had hoped.
This year’s submission may get criticized for being written in the first person rather than the “editorial we.” I feel very strongly about the topic; much of the paper is an account of how I learned about high contact ratio gears over the past 35 years. During my research I read some early papers and reference books that were obviously written before this unwritten, third-person narrator rule somehow gained currency.
Our gearing forefathers could be very passionate about their trade, and I think that is a good thing. There is no need to disguise personal experience in a detached and dispassionate voice.
Rather, our industry needs more passion, more opinion.
Estimating is a necessary evil in every shop. Nobody wants to do it, but if it doesn’t get done there is no business. Fortunately, we have better estimating tools available today than ever before. Several automated computer programs are offered to assist in calculating the time it takes to perform various machine operations. Computer-controlled machines make cycle times consistent and reduce scrap risk.
It wasn’t always this “easy.” Shortly after I became an “instant” gear expert (see previous posting), I was expected to weigh in on how much our new product line should cost. Long time D.O. James estimator Dick Kunkle welcomed me into the cloud of cigarette smoke that engulfed his cubicle and shared his shelves of reference books, computer printouts, and charts.
To this veteran estimator every drawing got expanded into a full-fledged process routing. In the absence of detail drawings, each item on a cross-sectional layout got “processed” through his system and its results were added to a summary form. No shortcuts were taken, so purchasing had to get lots of prices on forgings, bearings, seals, and other hardware.
Fabricated housings had to be exploded into dozens of burned out pieces and the total number of weld inches calculated. It didn’t matter what the finished weight was; if you needed a triangular piece you paid for a square in Mr. Kunkle’s system.
To me the real beauty was in the many charts and nomographs he had developed over the years for “special” parts like bevel gear blanks. The man had committed the capabilities of every machine in the shop to memory and was seldom proven wrong. If he told you the hobber couldn’t take a 3 DP hob, you could take it to the bank.
Even with this much “science” applied to it, estimating is a risky occupation. If the estimator listens to every complaint from the sales department — profits decline. If he or she sides with the shop incoming — orders fall. And everyone in the company thinks it takes too long to get a quote finished.
You no longer have to risk your health from the secondhand smoke to get involved in estimating, so why not see if you can help speed things up?
We would like to add our voice to those congratulating AGMA Technical Division VP Charlie Fischer on his retirement. I didn’t meet Charlie until he took up his AGMA duties in 1994, but immediately was impressed with his skill at keeping a meeting on track.
Remember that old saying that people want to know how much you care before they care about how much you know? Charlie’s face should be on that poster. Even with twenty or more engineers in the room he found time to make each person feel welcomed and respected.
There was no deficiency in Mr. Fischer’s personal knowledge of gears and he used his considerable background to deliver very clear reports on the activities of the many technical committees he observed. As part of AGMA’s ISO team his diplomatic skills were called upon to represent our country’s consensus position on controversial topics.
Given his hectic travel schedule over the past 20 years, Charlie is sure to enjoy staying at home and spoiling his grandchildren. His AMGA committee friends will miss seeing him in hotel conference rooms around the globe.
Live long and prosper Charlie!
PS: Our March/April issue has more information on Charlie’s contributions to our industry.
Reflecting upon “transformative technology,” I remember the sadness I felt at the Cincinnati Gear Company auction when a group of pristine condition MAAG gear grinders did not draw a single bid, even from scrap dealers present. You could tell from their appearance that these “dinosaurs” had been the pride of that firm right up until the end of operations. They were big, durable and precise machines that no one could afford to operate commercially anymore. Two newer CNC machines could out produce eight or ten of the MAAGs.
Almost every shop that I have worked in had a dinosaur or two stashed away for those “special jobs” that wouldn’t fit anywhere else. Some of the old machines are still highly sought after; gear milling machines dating back from 1910 are fitted with carbide gashing cutters and continue to earn their keep. Herringbone machines, especially in the larger sizes, are still making gears on a production basis.
We once had a line on a 12-foot-capacity herringbone machine at a close out auction. Unfortunately, our designated machine tool buyer picked the wrong moment to visit the rest room and returned to find the winning bidder already torch cutting the 1921 vintage device into handy pieces of scrap.
As the dinosaurs get melted down, future generations will have to content themselves with photos and grainy training movies. One of my favorite places in the Philadelphia area is the Mercer Museum in Doylestown. Henry Mercer collected pre-industrial era tools and opened his museum in 1916 to showcase the creativity and skill of our predecessors. I especially like the early 19th century clock making display (www.mercermusem.org).
I hope to eventually visit the American Precision Museum in Windsor Vermont (www.american precision.org), which celebrates our machine tool industry with interactive displays and miniatures. Any suggestions for other places to see vintage machine tools? Other than your shop or my garage. I’m the world’s worst machinist but I enjoy playing with my 1989 vintage Shoptask lathe/mill, serial number 2.
In the most recent issue of Gear Technology, the Publisher’s Page recounts the inaugural issue’s coverage of “transformative technology,” titanium nitride-coated cutting tools and CBN/Form grinding. While commonplace today, these new developments had an instant impact on the gear trade and set into motion changes that completely changed the way our industry operates.
The increased life of hobs and shaper cutters had a huge impact on the number of tools needed by high-volume users. Tool makers who once could count on shipping pallets of hobs to an automotive transmission plant every week had to cut staff quickly because orders plummeted. Tool shops were downsized, companies reorganized or merged, and experienced tool makers found themselves needing to retrain. No matter how you tried to spin it, increased tool life couldn’t be ignored in the marketplace.
CBN/form grinding, on the other hand, made ground tooth gears affordable in a much wider range of machinery. I was working in a shop with no gear grinding capability at all in May of 1984; no amount of political maneuvering was going to open up our parent corporation’s wallet for gear grinding equipment. We were soon unable to be competitive in special gearboxes for metal processing. A year later I relocated to a family-owned shop in the Philadelphia area where we attempted to revive a long-dormant Sheffield spur gear grinder. It didn’t take long to learn why it was mothballed; wheel prep was a nightmare and part quality wasn’t much better than well-hobbed, through-hardened components.
When the local grapevine started buzzing with news that Philadelphia Gear was getting more parts off a single form grinder than four well maintained MAAG grinders, old hands were skeptical. Those rumors were true and ground gears suddenly started to be designed into general industrial equipment.
Over the next ten years, job shops all over the country added gear grinders to their capabilities. Experienced gear grinders found themselves in high demand — the exact opposite of hob makers. So two “transformative technologies” had far different, “transformative” consequences for gear industry employment.
In my last posting I wrote about some of the projects I have been involved with to squeeze a bigger part in an existing machine. Most of the time things worked out great, but once in a while we still outsmarted ourselves.
We learned, for example, to verify and record the actual openings in our heat treat furnaces after learning that just because a part fit when cold did not mean it would come out when hot. A 72 inch gear is really a 72.44 inch gear at 1,050° F! The 72.25 inch opening was way too small when we needed it; a slow cool later, we were able to retrieve the part and re-heat it in a larger furnace for quenching. So there was no serious damage to anything — except our egos.
High capital costs and tight budgets are great incentives for rebuilding, modifying, and upgrading your existing equipment. Gear Technology readers have seen advertisements from firms that routinely add computer controls to veteran gear hobbers, lathes, and milling machines.
With a bit of outside help you might be surprised at what your maintenance mechanics can accomplish. We bootstrapped ourselves into a wonderful suite of freshly rebuilt carburizing furnaces at less than the cost of one completely new unit. The crew got plenty dirty and we had a false start or two, but the end results transformed the company.
And that transformation was not limited to the physical plant. I’ve heard it said that “experience comes from surviving moments of bad judgment.” Our newly “experienced” furnace rebuilding crew was not afraid of taking on bigger challenges as they came along — challenges that would previously have required expensive outside help.
Sometimes the first step to thinking outside the box is to be brave enough to take the box itself apart and re-imagine how it should go back together.