Recently I was invited to attend a talk on additive manufacturing hosted by the local chapter of the Product Development and Management Association (PDMA). My email invitation included a link to the Cincinnati PDMA Meetup group, which the organization used to set up and coordinate the details for this event.
If you’re not familiar with Meetup (I wasn’t), it’s a social network that allows users to create virtual groups based on interests that get together in the real world. Once you join a Meetup group, you can RSVP for its events, connect with other members and even contribute to crowdfunding to help pay for things like refreshments. It’s an interesting mix of social media and real-world networking and learning opportunities.
What struck me most about the PDMA Meetup was the free exchange of knowledge among the people at the event. Attendees ranged from manufacturers currently using additive manufacturing to those just learning about this technology or seeing it up close for the first time. The Meetup was a way for those newcomers to learn from others with direct experience, ask questions, and make contacts for follow ups. Maybe some of those relationships will lead to contracts or collaborations.
There are two newsletters that Modern Machine Shop emails to subscribers that serve as nice complements to the print magazine. Twice a month, we send out our “MMS Extra” newsletter that builds on the magazine by offering additional insights into the work and business of machining. Regular topics include unique shop innovations, newly posted products, the latest videos and more.
We also offer a weekly blog wrap-up newsletter that emails each Friday, as we don’t expect that you’ll have time to visit this blog every day. “The Shop” weekly newsletter gives you quick descriptions of the blog posts that appeared that week so you can read them at your own convenience. Topics include breaking industry news, road reports from tradeshows and additional insights that we can’t squeeze into our monthly print magazine.
Sign up to receive these free newsletters. That page also includes descriptions of newsletters from other Gardner Business Media brands covering additive manufacturing, automotive, composites, moldmaking, plastics and other industries and technologies.
Microfluidics industry R&D applications have called for milling channels with extremely smooth finishes into plastic or, as seen here, titanium plates. The channel here measures 0.006 inch and requires a 0.2 µm surface finish.
This July-issue feature article tells the story of how a single machine tool catalyzed a massive transformation at Integral Machining, a 6,000-square-foot contract manufacturer in the Toronto area. Thanks largely to the addition of Kern Microtechnik’s five-axis Evo, the shop is serving new customers that often demand tolerances measured in single-digit microns—far greater precision than anything it had handled before. What’s more, lessons learned in the process have helped improve operations on less demanding work as well.
However, the machine alone wasn’t enough. This shop had to learn new strategies in order push it beyond its advertised precision of ±2 µm on the part. Indeed, the more I talked to Andrew Sweeting, the machine’s chief operator, the more he reminded me of a smartphone “power user” (these are the people who really dive deep; they seem to have an app for everything, use mountains of data, and might even be willing to dive into the firmware to customize their device). Here are a few examples of thinking beyond standard features and functions:
Finding the kinematic point. Most five-axis machine tools are permanently configured that way—that is, the fourth and fifth axes are a permanent, integral part of the overall structure. That’s not the case with the Kern Evo. According to this machine tool builder, every machine has an “accuracy budget,” and each added component—an additional axis, a tool changer—detracts from that budget. To facilitate the kind of precision Integral Machining is achieving, the machine’s fourth/fifth axis table is installed only for the applications that require it.
For any job requiring tolerances tighter than about 5 µm, a crucial step in installing the table is finding the kinematic point, or the theoretical center about which the table pivots. Boiled down to its essence, this complex procedure involves moving the axes through their range of motion, stopping for periodic measurements against a standard with known dimensions (in this case, a System 3R chuck), and using the compensation tables in the Heidenhain iTNC530 CNC to adjust for error within four decimal places (0.0001 degrees).
Actively managing thermal compensation. With small, precise work, temperature is always a concern. That’s where the machine’s temperature management system comes into play, not to mention tight environmental controls in the segregated area of the shop where it’s housed. However, when surface finish presents just as much of a challenge as part geometry, simply letting the machine’s automatic thermal compensation system do its thing may well be a mistake.
For example, one job (pictured above) involved machining tiny channels into a titanium plate for a microfluidics R&D application. Trochoidal climb milling with a 0.004" end mill proved an efficient means of producing the slots to dimensional specifications. However, achieving 0.2 µm surface finish specification was another matter. Based on advice from Kern, the machine ran without cutting for about 15 min. (sufficient time for the tool assembly to “grow” to its fullest extent), then switched off Z-axis thermal compensation while the tool was in the cut. Reserved only for specific workpiece features with exceptionally stringent surface finish specifications, this strategy prevents the microscopic “hammering” motion resulting from the machine’s automatic response to temperature fluctuations.
Scoping out problems and sweet spots. To my knowledge, most manufacturers would never have reason to use the oscilloscope function of the machine’s CNC. Typically employed by machine tool builders and distributors for axis tuning, the oscilloscope measures electrical signals to determine the difference between the axes’ programmed positions and actual positions. Integral Machining, however, has learned to effectively employ this function for troubleshooting and for determining “sweet spot” cutting parameters that provide the smoothest machining for various cutting tools.
To learn more about how Integral Machining leverages the oscilloscope (and the Kern Evo generally), read the full article.
These inserts for expanded-beam fiber-optic cable connectors use the green lenses to focus and transmit light from one optical fiber to another. The bores holding the optical fibers were held to within +1.5/-0 µm of nominal diameter, positioning within ± 1.5 µm, and an N4-level (0.2- µm) surface finish.
“Your comment that the Japanese do not listen to music while working reminded me of a video that we show in our shop to new employees. Despite what people think about their ability to multitask, the human mind can really only focus on one task at a time. You can either listen to music or work with your hands. Take a few minutes to watch this YouTube video [embedded above].”
He went on to say: “I have been showing this video for a couple of years. The reason: our millennials. I have watched our youngest employees bouncing to the music in their headphones while either punching offsets into the controls of our very expensive CNC production equipment or ensuring the quality of our customers’ parts. We want them to enjoy their time at work, but they also need to understand their responsibility to our stakeholders to be productive in an extremely competitive global market.
“I banned the headphones. They are a distraction as well as a safety concern. While I have not banned cell phone use in the building, I have stressed that its use should be appropriate to work. Focus!
“That focus is important. We stress to the staff that anyone with several million dollars can buy every piece of equipment we own. There is nothing unique about the Tornos Deco, Tsugami, Index, Euroturn or Miyano equipment that we own. The only competitive advantage that we have is each team member’s brain working in conjunction with the brains of their co-workers.”
UL, a global safety science organization, has announced what it calls a Cybersecurity Assurance Program (UL CAP) for industrial control systems. Using the new UL 2900-2-2 standard, UL CAP for industrial control systems is designed to provide testable cybersecurity criteria to help assess software vulnerabilities and weaknesses, minimize exploitation, address known malware, review security controls and increase security awareness. UL CAP is intended for control system manufacturers who need support in assessing security risks while they continue to focus on product innovation to help build safer, more secure products. These steps will help protect the Industrial Internet of Things (IIoT). The program should benefit OEMs, machine tool builders, system integrators, and retrofitters who want to mitigate risks by sourcing products assessed by an expert third party.
Network-connected products and systems offer capabilities that promise significant boosts in productivity to manufacturing companies. Industrial control systems, for example, are becoming more interconnected, connectable and networkable, thus making data-driven manufacturing a practical reality on the factory floor. However, there are growing risks that threaten the security, performance and financial return on these control systems and the equipment they run.
“We’re aiming to support and underpin the innovative, rapidly iterating technologies that make up the Industrial Internet of Things with a security program,” says Rachna Stegall, director of connected technologies at UL. “The more industrial control systems become interconnected with other devices, the greater the potential security risks. The Cybersecurity Assurance Program’s purpose is to help manufacturers, purchasers and end-users mitigate those risks via methodical risk assessments and evaluations.”
Developers of UL CAP solicited input from major stakeholders representing the Federal government, academia and industry to elevate the security measures deployed by companies, and agencies who may have equipment and devices connected to digital networks. For example, automotive OEMs and Tier 1 suppliers, along with the many job shops and manufacturing subcontractors that support them, make up a critical supply chain that must have cybersecurity measures as a priority. UL CAP is being presented as a means for evaluating the security provisions of control systems with these supply chains.
UL’s evaluation of industrial control system security uses UL 2900-2-2, which is within the UL 2900 series of standards. This series outlines technical criteria for testing and evaluating the security of products and systems that are network-connectable. These standards form a basic set of requirements to measure, and then improve, the fitness of products and systems from a network security standpoint. UL 2900 is designed to incorporate additional technical criteria as the security needs in the marketplace evolve.
UL CAP can help vendors identify security risks in their products and systems, and it suggests methods for mitigating those risks. The UL 2900-2-2 standard can be applied to industrial control system components such as:
Programmable logic controllers (PLCs)
Remote network terminals
Human-machine Interfaces (HMIs)
Input/output (I/O) servers
Machine tool control units
Intelligent devices such as sensors
Industrial control systems that meet the requirements outlined in the standard enables them
to be certified by UL as “UL 2900-2-2 compliant.” Additionally, since security is an ever-
changing challenge, UL 2900-2-2 can be used to evaluate a vendor’s processes for design, development and maintenance of secure products and systems.
Click here for more information on UL CAP, or visit Booth E-4135 at IMTS, To register for a free webinar about this program on October 11 at 10:00am CST, click here.