Today's—and Tomorrow's—Machines: Not the Same Old Grind
by Jack McGuinn, Senior Editor
Of all the gear making processes relevant to gear manufacture, machine grinding is certainly among the most precision-demanding. As well, gear grinding—when done right—is instrumental in extending gear lifetimes—particularly those of complex gears—in that it accurately lays out a timeframe for predictive maintenance and end-life.
For a snapshot of the current state of gear grinding we talked to three machine makers with major standing in the industry—Kapp, Reishauer and Höfler (as represented by Great Lakes Gear Technologies Inc.)
Dennis Richmond, Reishauer vice president
Bill Miller, Kapp vice president of sales
Ray Mackowsky, president of Great Lakes Gear Technologies
Gear grinding has made significant advances over the years—driven by a number of factors including customer requirement demands, new standards, complex applications and more. But of course end-users and other facets of the gear industry are known for a "what have you done for me lately" mindset when contemplating technology breakthroughs. Accordingly, we begin things by asking our three participants for their view of what signifies "state-of-the-art" these days.
"Current state-of-the-art for Reishauer would have to be our smallest machine, the RZ 60," says Dennis Richmond, Reishauer vice president. "It's a machine designed primarily for—but not limited to—the automotive industry for grinding planetary pinions in the range of 10 seconds, floor to floor. All idle times have been reduced or eliminated without sacrificing quality, reliability or safety. It's all about the lowest cost of ownership these days.
Ray Mackowsky, president of Great Lakes Gear Technologies—Höfler's U.S. rep company—provides his perspective.
"Today there are lots of features that define state-of-the-art," he says. "Innovations in machine design technologies such as torque motor table drives for improved accuracy and reliability; Granitan component construction for improved thermal stability (Granitan is a registered trademark used for machine bases of synthetic stone) process strategies such as high-speed PowerStoke gear grinding; and, of course, advanced user-friendly software for not only exacting profile modifications but to expedite fast set-ups which makes grinding simpler and more efficient."
And over at Kapp, Bill Miller, vice president of sales, adds this.
"Flexibility—the capability to utilize multiple technologies for specific applications," he says. "And," he adds, "efficiency derived from short set-up times via on-board inspection and quick-change tools. And productivity driven by minimum non-grinding times through multiple-spindle machines."
The flip side of that coin is identifying the key issues and challenges confronting machine makers today.
"Meeting customer demands for quick delivery to meet exploding order intake," says Kapp's Miller. "The exceptional management of a privately owned company is able to react more quickly to changing conditions with timely decisions and focused leadership."
And at Reishauer—ditto.
The Reishauer RZ 260 is designed primarily for—but not limited to—the automotive industry for grinding planetary pinions in the range of 10 seconds, floor to floor, thereby reducing or eliminating all idle times without sacrificing quality, reliability or safety (courtesy Reishauer).
"The demand for the shortest possible machine delivery times," says Richmond. "Ten months ago we saw a huge spike in orders that has not subsided to date. This puts added pressure on our suppliers to improve their own internal efficiencies to meet the demands."
GL's Mackowsky adds this to the mix.
"For us in the U.S. today, most gear equipment is made off-shore and the exchange rates and escalating costs to our customers are key issues," he says. "Therefore Höfler—as an example—has invested very heavily in reducing costs via efficiencies in manufacturing and assembly while keeping a keen eye on increasing quality and value to our customers."
And then there's the dreaded, ongoing supply chain dilemma—a problem facing just about every aspect of the gear industry. Are machine makers impacted by supply shortages? Counterfeit bearings? The question is a no-brainer for Mackowsky.
"Of course the challenges are similar! Today most gear grinder manufacturers utilize the latest innovations in bearings, drives, controls, etc., and during this current upsurge in business those components must be acquired on a proactive basis in anticipation of business, versus reactively, which limits response time and deliveries."
"Yes," Miller agrees. "Superior quality—purchased components for gear finishing machines are only available from a relatively few suppliers. Substitutes cannot be interchanged without risk. The leaning of many key suppliers compounds the capacity constraints today."
And then there is the aforementioned, often unrealistic customer demands and requirements, new applications and ever-tightening standards/tolerances to contend with. What steps do machine makers implement to meet those challenges and stay competitive?
"We try to stay one step ahead of our customers by anticipating new challenges we expect to face," says Richmond. "For example, Reishauer was the first company to realize that a single work spindle machine could never meet the increasing demands of high-volume production.
"Since the introduction of the RZ 150 almost nine years ago, we have developed other two-spindle machines." He continues, "Our customers have indicated that we're on the right track by purchasing the machines in large numbers, and our competitors have acknowledged this solution and are debuting their clones."
But for Mackowsky, the question assumes a faulty premise. At Höfler, for example, a customer challenge is a Höfler opportunity.
The Höfler Rapid 6000—"the world's largest gear grinder"—is designed for large and heavy workpieces up to 6,000 mm and 100 tons. It combines the largest dimensions with absolute precision, speed and flexibility and provides topologically correct results at reduced grinding times (courtesy Höfler/Great Lakes Gear Technologies).
"Firstly, we rarely look at customer demands as unrealistic, only as a challenge and possibly as a means to improve our gear grinders," he says. "As I mentioned before, innovation, cost containment and constant R&D efforts are key to meeting customer demands. However, in the case of Höfler, whom we have represented during the last dozen phenomenal years of growth, they/we have understood the need for a great team of application support engineers which travel and assist our customers to overcome these challenges. This is a costly endeavor—but crucial to success in this industry."
For Kapp—much the same—and then some.
"Development, testing, development, testing!" says Miller, adding, "And establishing partnerships with customers to test under real-life production conditions."
And let us not forget software—the brainy ghost in the machine that orchestrates every movement. Any machine maker of note writes its own.
"I think most machine tool builders develop their own MMI (man machine interface)," says Richmond. "(It) is not something commercially available from control manufacturers for sophisticated machines that have several axes that need to be simultaneously controlled within microns. The more intuitively we can write the software and make it easily understood and foolproof, the more success we'll have selling product. It's that simple."
"I don't know about others in this industry," says Mackowsky, "but Höfler has a large and tremendously capable software staff. (They do) constant R&D with our applications group and also create all of their GearPro proprietary software for process and machine HMI's in-house, which is used on all Höfler grinders and hobbers. Having control of all aspects of the software development is very important and a core competence to maintaining leadership in this industry."
Miller says that "Kapp-Niles develops its proprietary software in-house, as it requires an intricate understanding of the technical abilities of the machinery—as well as its limitations. Immediate access and close cooperation with in-house equipment designers allow for the interaction and feedback crucial for good software development."
Of course the performance of gear grinders is significantly augmented by grinding wheels and their composition—a sort of razor-razor blade scenario. To that point, grinding wheels have seen many upgrades over the years, and today is no different. Indeed, many machine makers manufacture their own.
"As you know, Reishauer has recently opened a grinding wheel manufacturing plant designed to support the size and consistency of wheels used on Reishauer machines," Richmond says. "For decades, we have lead the development process for traditional wheel manufactures. We now have our own product that eliminates the middle man, allowing us to offer the best possible solution to the customer.
"We've been manufacturing our own diamond dressing tools for more than a decade. By offering a total solution we can optimize the process, assuring the customer the lowest cost-per-piece. Our reputation has been built on this premise."
The Kapp KX 500 Flex, as with other KX models, offers continuous generating grinding, discontinuous profile grinding, or a combination of both methods. Among its other features are a rotating circular table that incorporates the tailstock support. The profile dressing unit is rotated into dressing position at the work spindle by the circular table and is flexible enough to use either conventional dressable worms or profile grinding wheels. The unit also accommodates a single or twin spindle dresser (courtesy Kapp).
And as Kapp's Miller points out, grind wheel development it is a never ending process.
"It is an evolutionary endeavor, testing more productive abrasives to achieve faster yet safer grinding processes," he says. "Our grinding wheel design approach includes various combinations of simultaneous roughing and finishing tools and also a multi-rib grinding wheel designed for finishing several gear teeth in one pass. Advanced simulation software optimizes generating tools and dressers."
Great Lakes' Mackowsky says Höfler, for example, takes a different approach—outsourcing.
"Höfler works with all the major abrasive manufacturers, testing new abrasives as well as refining software to suit the latest dressable and even plated wheel abrasives to stay on the cutting edge. Today we see new ceramic bonds which are making dressable CBN very attractive in certain areas of gear grinding.
So what's the Next Big Thing in machine grinding technology? It depends upon whom you ask.
"Form grinders today are already extremely advanced both in mechanical construction and process capabilities," says Mackowsky. "Advancements are constantly being developed with additional features and capabilities which will not only improve quality and reduce costs, but will custom-address specific market segments and increase penetration into previously cut gear or generating segments of the industry.
"Therefore gears that were previously considered candidates for generative worm wheel grinding, shaving or finish hobbed, are being replaced by a new generation of high-performance form grinders that have more flexibility and features. At (this year's Gear Expo) we will show some unique capabilities, so I will defer more info until then."
For Kapp's Miller, it's all about the software.
"Intelligent software will continue to elevate grinding machines to more advanced levels," he says. "The ability to calculate and predict variables ahead of time and make automatic adjustments are key to productivity and accuracy expected from sophisticated gear grinding equipment."
Saving the worst for last, we felt compelled to ask each company if the universal shortage of skilled workers impacts machinery makers as it does most other sophisticated manufacturing endeavors. The answer, unfortunately, is a uniform "yes."
"The lack of skilled help is a worldwide issue," says Richmond. "We have an ongoing apprentice program in Switzerland to seed our future workforce. There are times when we'll have to rely on suppliers to help us meet demand with those 'less critical' components until such time that the high demand can be met by our existing staff. To this end we're currently seeking qualified individuals for our service staff in the U.S."
For Great Lakes/Höfler, much the same, save for the fact that Höfler's German DNA—i.e., Germany's long-held support for its manufacturing base—provides a leg up on the learning curve.
"Yes, manufacturing faces the same challenge worldwide as there are few educational systems that recognize the need for expertise in our fields," says Mackowsky. "However, at Höfler we still maintain an extensive apprentice program in conjunction with the local school system which results in a constant flow of new employees that, over time, become the future of the company and the gear machine industry."
And finally, Kapp's Miller points out that "Machine manufacturers must respond to the ever-increasing customer demand for new technologies with highly skilled and creative technical staff. These positions are not filled or eliminated according to economic cycles."