Sinker EDM Machines Drive Innovation at Summit Tooling

Strategic investment in advanced sinker EDM machines has enabled Summit Tooling to eliminate troublesome outsourcing and take on new business opportunities with unprecedented levels of complexity.

“In my career as a toolmaker, I’ve never seen the value of doing what everyone else can do. At Summit, we focus on solving the toughest, most unconventional challenges for our customers,” said Dan Martin, president of Summit Tooling which is located in McHenry, Ill.

According to Martin, developing these solutions requires bright, creative minds and enabling high-performance machining technologies. He attributes many of Summit’s recent advancements to new investments in high-performance sinker EDM machines that have paved the way for new ways to design, program and produce molds.

Martin has diverse experience and a unique understanding of the toolmaking trade through his work with a variety of die and mold shops. The quality, integrity and timeliness of his work through the years did not go unnoticed, as Martin quickly built his own following of loyal customers. In 1996, his wife, Michelle, armed with a background in business management and marketing, suggested they open up their own business—and Summit Tooling was born. Since its inception, the company has grown from two employees in a 2,500-squarefoot space to 30 employees in its current 30,000-square-foot facility.

Summit has two divisions, Summit Tooling and Summit Plastics, both located in the same facility, forming a one-stop shop that services customers in everything from design to final part production. This ability to conduct full part processing in one facility is a key aspect to Summit’s prototyping process, enabling the company to sample and debug new tool designs on the fly. Summit’s reputation for innovative prototype mold making has attracted many large corporations in the medical, packaging, electronics and automotive markets, as well as entrepreneurs looking for assistance in bringing their concepts to life.

“It’s important for manufacturers to diversify their markets. As a general rule, we try to never have more than 30 percent of our business in any one industry,” said Martin. “This philosophy has served us well. Not only have we been shielded from the recession, but also our toolmakers’ skills have been sharpened with new and different challenges on a regular basis. It’s this type of culture that keeps everyone excited about their work.”

According to Martin, a culture of creativity and diversity must be supported by the appropriate applications and technologies. “Machining technologies can either limit you or inspire you. To maintain a culture of innovation and problem solving, we’re in constant pursuit of machining capabilities that can change everything from how we design to what we produce,” explained Martin.

When the company found itself hindered by insufficient milling speeds in 2006, it began researching high-speed machining center capabilities. Out of the 12 different machines evaluated, Summit chose a Makino S33 vertical machining center. This investment was later followed by a second S33 and an a61 horizontal machining center in 2006.

“After the first S33, we found that Makino was not only a machine tool manufacturer but a service organization as well,” said Martin. “With each investment, Makino has ensured that we are using the technologies to the fullest potential. The ongoing support was a primary consideration when we began evaluating sinker EDMs in 2011.”

Improved Sinker EDM Machines

Prior to upgrading its EDM department in 2011, the company was operating a set of nine conventional sinker EDM machines, which Martin described as “a bottleneck in flexibility that limited engineers’ design capabilities.” This sentiment was shared by the company’s toolmakers who expressed concerns that they had reached the machines’ limitations.

“The accuracy, quality and consistency were no longer meeting our expectations, making it difficult to produce new mold designs that required tolerances under 0.001 inches,” stated Brian Parker, mold maker at Summit. “Even the electrode process was more involved, requiring extra hours to design and build effective flush holes.”

In 2011, Summit acquired two Makino EDAF2 sinker EDM machines providing Summit with the capabilities needed to increase flexibility, efficiency and ultimately the bottom line by taking on new business opportunities. According to Martin, “These machines eliminated outsourcing of small-hole operations, decreased electrode consumption by approximately 40 percent, reduced cycle times by 30 to 50 percent, and we still have the capacity to take on additional work. Supplementing these sinker EDM machines with the creative problem-solving skills of our engineers has enabled us to bring new designs to life that customers previously had never thought possible.”

“With the EDAF2s, prior issues are no longer a concern; we’re burning flush-free and holding tolerances within plus or minus 0.0001 inches. The machines’ performance, reliability and 16-tool-capacity automatic tool changer have allowed us to focus more time and resources on optimizing our tooling and electrode designs for more efficient and effective solutions.”

Summit’s EDAF2s are part of Makino’s latest line of sinker EDM machines designed for precision metal cutting under uncontrolled temperature environments and long hours of unattended burning. The EDAF sinker EDM platform features a new mechanical design for increased rigidity and reduced thermal distortion as well as an improved servo control for quicker responses to the spark-gap monitoring system. The machine is equipped with Makino’s latest sinker EDM advancements, including SuperSpark and ArcFree technologies.

SuperSpark

SuperSpark is a combination of advanced sinker EDM technologies which can improve total machining times by up to 30 percent over conventional sinker EDM technologies. It is especially effective for deep rib and drafted cavities. SuperSpark technology can take advantage of cavity draft by employing high power settings at the top of the cavity and reducing the power settings as the electrode machines deeper to assure that cavity walls will clean up in the final orbiting. SuperSpark technology also incorporates adaptive jump functions ensuring faster burn times and improved quality.

ArcFree

To prevent destructive DC arcing, all EDAF sinker EDM machines are equipped with ArcFree technology which is designed for difficult and unstable cutting conditions. While most modern sinker EDM machines incorporate anti-arc, or arc-prevention circuits, Makino states that ArcFree technology can be relied upon to burn any application, unattended, with virtually no possibility of developing destructive DC arcs during the burn process. ArcFree is also capable of effectively dealing with large changes in electrode contact area. It dynamically senses and adjusts spark energy density. For manufacturers, this means no stoppages during the burn process, secondary cleaning operations, or scrapping of workpieces.

Small Hole Machining

After purchasing the EDAF2, the company discovered it could apply the machine’s optional fine-hole attachment to bring small hole machining back in house. For several years prior to this investment, the company relied on outsourcing for its small hole machining.

“Within the medical sector, we started working with nano molds featuring small holes of diameters ranging between 0.003 inches and 0.01 inches,” explained Martin. “The outsourcers we were working with had a lot of difficulty producing these holes on a consistent basis; in some cases, we were required to redesign our tools to accommodate for these limitations. The process took anywhere from two to three weeks and was still hit or miss at best.”

“After enduring daily headaches of inconsistent results, redesigning of tools and nail-biting lead-times, the EDAF2 has been a life saver. Its small hole machining capabilities have revolutionized the way we design and produce tools featuring fine hole details. Beginning with our first run of the machine, we’ve achieved precision accuracy and consistency in shape, straightness and location. The entire tool, including fine holes, can now be produced in less time than it previously took for outsourcing alone.”

The small hole machining accessory consists of a special head that includes a high speed rotating spindle; a W-Axis base casting including drive motor, linear guide and ball screw, a W-Axis Arm Unit which supports a Middle Guide stabilization apparatus; Die Guide, and Guide Plate. The small hole machining accessory also includes special small hole technology and allows both automatic electrode changing as well as automatic electrode guide changing.

The small hole machining accessory and its associated technology allows the EDAF2 to produce highly accurate very small holes (as small as eleven microns), large quantities of small holes (7,500 0.33mm holes in one plate with a positioning accuracy of +/- 2.5 microns), and precise small holes with high L to D ratios (.132mm holes with 100:1 L to D).

C-Axis Configuration

According to Summit, the EDAF2 provided a host of new capabilities that few other technologies are capable of achieving. For example, the EDAF2’s C-axis configuration and indexing capabilities have enabled Summit to build multiple features into a single electrode—a practice that has reduced overall electrode consumption and production time.

“With the ability to pulse and burn in any direction through simultaneous axis movement, we can make electrodes do almost anything a cutter can do,” said Martin. “It doesn’t matter what shape or location the design requires; with the proper electrode positioning control, we can accomplish nearly any desired feature.”

Summit recently took full advantage of this capability when EDM’ing a cashew gate. Designed to connect hot runners to mold cavities, cashew gates are rarely machined directly into mold cavities due to challenging feature access, poor flushing conditions and DC arcing.

Under conventional sinker EDM technologies, these features would be considered risky, if not impossible to produce. The EDAF2 overcomes these challenges with its combination of SuperSpark and ArcFree technologies, and its ability to introduce simultaneous, multiple axis machining required for these types of features. Together, these technologies enable appropriate positioning of the electrode while monitoring and adjusting burn conditions to ensure finishes and accuracies meet required specifications.

“Despite successes with all other complex features, we weren’t setting our expectations too high when testing the first cashew gate,” said Martin. “When the workpiece came out of the EDM clean and machined to spec, we realized that this investment would offer us the flexibility to take on new design challenges for years to come.”

Pushing the Envelope

Maintaining its commitment to innovative solutions through creative problem solving and enabling technologies, Summit has already begun preparing dynamic plans for its future. Martin describes his strategy for the future as a two-pronged approach that’s driven by technology and application.

“The market isn’t static. It’s constantly evolving, and customers are always looking for new and improved solutions,” says Martin. “In order to sharpen our skills and stay ahead of the competition, we need to make sure that we’re serving industries that encourage innovation and investing in technologies that give us flexibility in our design process and reliability in machining performance.”

“A manufacturer’s capital investments must demonstrate a commitment toward continuous improvement,” said Martin. “It has the ability to not only shape your products, but the future of your business.”