Peter Zelinski has been a writer and editor for Modern Machine Shop for more than a decade. One of the aspects of this work that he enjoys the most is visiting machining facilities to learn about the manufacturing technology, systems and strategies they have adopted, and the successes they’ve realized as a result. Pete earned his degree in mechanical engineering from the University of Cincinnati, and he first learned about machining by running and programming machine tools in a metalworking laboratory within GE Aircraft Engines. Follow Pete on Twitter at Z_Axis_MMS.
Interest is high in CNC machining as a career path. At least, it is far higher than it once was. I’ve seen this repeatedly in recent facilities I’ve visited. Illinois manufacturing association TMA came close to ending its training efforts altogether in recent years, but now has a newly opened instructional facility seeing surging enrollment. And across the border in Wisconsin, the impressive Moraine Park Technical College has a healthy machining program (to the extent that this institution’s struggle now is to draw students into remaining underserved fields, such as HVAC). In the metalworking industry, outreach efforts aimed at attracting young people seem to have had an impact.
But one thing these outreach efforts often lack is a specific way forward. If a young person becomes interested in machining—say, if a teenager in high school or junior high has this interest—then what should he or she prepare to do to follow this interest and proceed into this career?
I think this document created by Matt Schowalter, who is a machining group lead at Gauthier Biomedical in Grafton, Wisconsin, serves as a useful complement to that outreach. In it, Mr. Schowalter describes his own machining career path and the steps he took, and he advises aspiring machining professionals in the steps they might take to follow a similar path. He created the document entirely out of his enthusiasm for his work and his desire to help others thrive in the same career. The link above is to a PDF download, or find a version he posted on LinkedIn.
Daniel Miller is the instructor at a new Heidenhain training facility where students receive hands-on instruction with company’s CNC on a five-axis machining center.
Soon, many builders selling machine tools with a Heidenhain control will offer vouchers for a week of free CNC instruction at the control maker’s Chicago-area U.S. headquarters. This voucher program is in development, the company says, and an important element of the program is already in place. I recently paid a visit to the company’s newly opened training facility in Schaumburg, Illinois, where students acquire hands-on experience with the control by running a five-axis Hermle machining center.
Getting new users familiar and comfortable with the CNC is only part of the goal of the company’s training, Heidenhain says. The company’s CNC is unfamiliar to many shops, so helping new users quickly adapt is certainly a benefit. However, the much larger benefit the company sees is in making sure that users are aware of the extent of what the control can do.
Leaving powerful control capabilities unused is too common, says company CNC training instructor Daniel Miller. He says he recently visited a shop machining blisks where he observed that the shop was accepting an unnecessarily light depth of cut because of chatter. He taught staff members there how to use the Active Chatter Control (ACC) feature of their CNC, which manipulates the machine’s feed drives to produce damping, thereby reducing the effect of chatter at frequencies up to 100 Hz. Thanks to this feature, the shop was able to increase its depth of cut and increase its productivity. Heidenhain did not make a new sale in order to bring about this success, because it involved applying a control capability the shop already owned.
A similar recent story involved a mold shop owner, Mr. Miller says. The shop owner recognized the value of ACC when he happened to be walking by a live demonstration of it at a trade show. The difference in cutting performance when the capability was turned on and off was audible, and he followed the sound to investigate. In his case, he did not have this capability on his own machine, but the shop was a Heidenhain user. He had the capability added as soon as understood the value.
Mr. Miller says a similar, related feature of the CNC is Adaptive Feedrate Control. This capability monitors spindle load and adapts the feedrate override accordingly. When used in conjunction with trochoidal milling, for example, it speeds the milling pass significantly, because all of the air cutting within each loop of the trochoidal path can be taken at a user-specified override of perhaps 150 percent, reducing cycle time.
The hands-on basic training course with the Heidenhain control in the new facility lasts 4.5 days. The company will offer an advanced course for experienced users as well, and the new facility also provides a setting for customized training for companies in search of this. The latest example is a medical device maker that has asked Heidenhain and Mr. Miller to train its machining staff in more advanced use of machine tool probing for machine verification and on-machine inspection.
In a post on Hurco’s CNC machining blog, company applications engineer Mike Cope describes how the fixture shown above was implemented to allow a five-axis machining center to achieve not just five-sided machining for one part, but five-sided machining for all of the workpieces shown here with a single cycle.
Programming the four different pieces at these four different orientations would seem complicated, but Mr. Cope explains that it can actually be accomplished using straightforward control features. A “transform plane” function is used to relocate the program origin from the center of the workpiece to the peak at the center of the fixture, and also to tip the coordinate field to match each part’s 20-degree angle. Then, a “toolchange optimization” feature is used to allow each tool to make the relevant cuts on each of the parts before the tool is changed out. The result is five-sided machining gracefully expanded into multiple-workpiece machining.
The recent Methods open house and technical seminar event included the public premiere of its new partnership with 3D Systems. Seen here at the Methods event (the tallest machine just past the crowd) is the 3D Systems Prox300 machine for production 3D printing of dense metal parts and a selection of parts grown on the machine.
Methods Machine Tools’ “Techfest 2015” event was the public premiere of the company’s newly signed partnership with additive manufacturing technology supplier 3D Systems. Alongside its machine tool offerings from brands such as Nakamura-Tome, Kiwa, Yasda, Feeler, FANUC, Hanwa and Current EDM, Methods will now also supply 3D Systems equipment for additively producing polymer, ceramic or dense metal industrial parts.
Significantly, Methods says it will also help companies succeed with these additive technologies. In the machine tool sphere, the company aims to be a “solution” provider rather than solely an equipment provider, and it is known for turnkey installation of engineered systems combining machining technology with support equipment such as automation. Company President and CEO Bryon Deysher says the company will bring the same kind of engineering support to its sales of additive manufacturing technology.
“We are all in,” he said, describing his company’s commitment to additive manufacturing in remarks to an audience of attendees to the Techfest event. One of the challenges of additive manufacturing is that large companies can afford to invest in the learning curve necessary to succeed with additive, but small to midsize manufacturers struggle with this. He says Methods’ aim will be to fill this very gap, by staffing up with technical personnel focused on additive manufacturing who can guide customers along the way to successfully and efficiently applying this technology to industrial production.
Growing that staff will be part of Methods’ long-term investment in advancing additive technology, he says. He expects manufacturers will evaluate additive with a similarly long view. “I believe, if you are not thinking about this now, you’ll wish you were in two years,” he said at the event.
One of the company’s new hires is Benjamin Fisk. Until a couple of months ago, Fisk was a manufacturing technology manager overseeing AM efforts at Pratt & Whitney. Now, he has joined Methods as the general manager of what will eventually become a nationwide additive manufacturing team for the company, ready to support the AM efforts of companies much smaller and less well known than his former employer.
For these small and midsize manufacturers, he says, there are significant challenges today that inhibit additive manufacturing gaining ground. The burden of AM development and integration generally falls on users, he says. When it comes to development, a general lack of process knowledge leads to significant developmental costs. And when it comes integration, this effort has to be inclusive of a complete process from design through inspection.
“You can’t think about 3D printing as just a standalone process,” Fisk said.
Methods can help with this entire range of challenges, he says. The company can engineer a system for additive manufacturing that includes postprocessing equipment and other support capabilities. And it can assist customers to refine and prove out not just the additive portion of the process, but instead the entire part-making sequence including the additive step.
The Techfest event showed various equipment likely to be included in processes such as this. In a conversation with Fisk, I asked him to indicate machine tools at the event likely to be useful for processing 3D-printed metal parts. He pointed to wire EDM first, as this is frequently the best method for removing printed parts from their build platform. Next in the sequence might be a small five-axis machining center, he said—that is, a machine able to make the necessary finishing passes for the kind of geometrically intricate workpiece that additive manufacturing is able to produce.
The integration with machining is vital to success of additive manufacturing, because production AM parts almost always require machining for critical features and tolerances. Methods says an additive part-making process might include post-processing capabilities such as wire EDM (left) for cutting the part from the build platform as well as five-axis machining (right) for finishing complex forms. The company sees its ability to provide all of these capabilities—additive and subtractive—as being one of its important strengths in advancing AM.
Another capability seen at the event was robotic loading of both standalone and multiple machines. Integrating robots is a common part of Methods’ turnkey engineering. The company’s robotic installations to date have been for subtractive machine tools, but now this same kind of integration of automation might soon be applied to production processes involving additive manufacturing as well.
There was a time when EDM machine maker Chmer (Taichung City, Taiwan) might have expected high speed milling to take the place of a significant amount of die sinker EDM work. The company developed a line of high speed milling machines to complement its sinker, wire and holemaking EDM machines in anticipation of this change. But things didn’t work out that way—illustrating, among other things, how difficult it is to predict technology adoption. On a recent trip to Taiwan, I had a chance to speak about this with Chmer Marketing Director Brad Wang.
While the ability to take fast, accurate cuts at high feed rates potentially makes milling a contender for certain complex die/mold forms that sinker EDM is used to produce, EDM is still more efficient for features such as deep cavities, fins and many thin walls. These features occur just often enough that high speed milling has not been able to unseat the established technology to any considerable extent. However, high speed milling has proven popular among Chmer’s customers nevertheless, not as a replacement for EDM but as a complement. The fast, accurate cutting is efficient for roughing complex mold forms before the sinker EDM is used to complete those features that EDM is still the best at finishing.
The technology needs and preferences of customers reveal themselves over time, Mr. Wang says. His hope is for Chmer to continue to adapt. Here are the EDM features and capabilities right now that he sees as becoming increasingly important:
1. Linear Motors. Among each of the company’s EDM types (and its milling machines) are models equipped with linear motors for axis motion. Linear motor machines cost more than machines driven by ballscrews, Mr. Wang says, but these motors save cost through reduced maintenance while improving the accuracy of the machine. Compared to conventional drives, a wire EDM machine with linear motors can generate sharper corners on precise components such as die punches. More, linear motors maintain their accuracy over time. This is not the case with ballscrews, which wear and become less precise over time due to the ongoing surface-to-surface contact.
2. Machine Monitoring. Applications of EDM often involve rows of machines all running largely unattended because the cycles are so long. The unattended nature of the process makes the machines ideal for monitoring systems permitting remote viewing of the current status of the machine as well its performance history over time. Chmer’s in-house control has enabled the company to develop its own remote monitoring system, among other special features. (Read on.)
3. Ease of Use. The in-house control has also enabled Chmer to develop a programming system enabling inexperienced users to employ EDM effectively. An operator can enter the workpiece material and diameter of the wire along with the desired roughness of the machined surface to let the control automatically set the cutting conditions and parameters required.
4. Hole Making. Among the three EDM types, holemaking looks to offer the most potential for future growth, says Mr. Wang, thanks to the long-term likely demand for cooling hole machining in turbine components by the aerospace sector. Key capabilities here include precise CNC interpolation to give small holes with a diffuser (open funnel) form at the mouth, as well as integration with B-axis indexing for the array of angles characteristic of the set of holes in a typical blade.
Chmer’s AD4L is a linear-motor equipped holemaking EDM.