Mold-and-die shops thrive on the latest technology in tooling, software, and machines. Process success often depends on using best-in-class solutions from the past as well as from the latest advances of today. New ways of using older technologies often depend on advances in enabling technologies.
A case in point is the emergence of circle segment end mill technology for full five-axis profiling. Circle segment cutting tools now offered by any number of cutting tool suppliers had to wait until full five-axis machining technology and CAM programming from software providers like Mastercam and Open Mind Technologies were able to handle it.
“The circle segment end mill is an effective replacement for the typical ball nose end mill that is used for semi-finishing and finishing molds,” said Bryan Stusak, national product manager-milling, Iscar USA, Arlington, Texas. The circle segment end mill features a cutting edge that is a segment of a large diameter arc that reduces the number of stepovers and the cusp height of machining passes in the mold. The net result is a smoother surface finish and reduction of cycle times by as much as 50 to 90 percent, according to Stusak.
Designed for finish and semi-finish machining, Iscar’s version of the circle segment end mill, the NEO Barrel, is available in Multi-Master and solid-tool configurations in 5/16, 3/8 and ½" diameters (7.94, 9.53 and 12.7 mm) in two different grades. “In addition to mold cores and die cavities, applications include aerospace and power generation blisks, turbine blades, medical orthopedics, prosthetic devices, and implants,” he said.
For roughing in mold-and-die work, Iscar has extended its small-diameter, fast-feed milling platform, LOGIQ4FEED, with larger diameter tools. Introduced two years ago in ½ to 2" (12.7 to 50.8 mm) sizes, the LOGIQ4FEED family of small-diameter feed mills have been extended with the addition of 2 to 5" (50.8 to 127 mm) diameter tools.
LOGIQ4FEED tools feature a narrow, bone-shaped, double-sided insert with four cutting edges. The design is well suited for roughing deep mold and die cavities. “The narrow, rectangular-shaped inserts have a cutter body with more mass, allowing more inserts to be put around the periphery of the cutter body, boosting productivity,” said Stusak. In moldmaking, where productivity is key, getting more inserts around the perimeter allows higher feed rates per revolution, minimizing step marks in the Z axis and the amount of material that must be removed in finishing.
“The bone shape provides side clearance for evacuating chips and avoids pinching the chips between the flank of the insert and the wall cavity,” he continued. “It’s an aggressive cutter geometry, almost like a helical cutting edge that aggressively slices into the workpiece, making it very free cutting.”
LOGIQ4FEED is available in several cutting edge geometries. The T-Land insert is for general-purpose materials and a high positive geometry is for difficult-to-machine stainless steel and high-temperature alloys. The following geometries are available with reinforced corner radius in T-Land: HP (Hi Positive); T-Land RM; and HP RM (reinforced cutting edge) to relieve pressure from the smaller corner radius for smoother finish and more robust insert.
Component Complexity Demands New Solutions
The complexity of mold-and-die components is increasing across the board, according to Lars Faller, application engineer for Siemens Industry Inc., Elk Grove Village, Illinois. “Controls are becoming much more advanced, more reliable, and even faster and more rugged, which allows for increased efficiency in customer operations. In addition, more and more customers are looking for transparency in their operations in an effort to maximize their profits,” he said. “In-process workpiece probing, for example, allows them to validate the states of the various machining processes and tools adequately before the part comes off the machine.
“We know that when we design something in a digital environment, such as a CAD program on a computer, everything is flawless,” Faller continued. “Lines, angles, and arcs enjoy perfect geometric transitions, but we also know that once we get down to the average manufacturing floor, we rarely get to revel in a perfect world scenario. Machines tend to grow and shrink in size with varying temperatures, and tools get worn out and have to be replaced.”
Historically, three-axis VMCs (vertical machining centers) were primarily used for die/mold work, as this provided a stable platform and helped ensure accurate surface finish, though at the cost of speed. “With the recent introduction of the SINUMERIK ONE CNC platform, we have the ability to adjust high-speed and contour tolerance allowance settings right at the control, without producing unfavorable mechanical vibrations—which will inevitably show up in the surface finish of the workpiece,” said Faller. “Compared to the old way, this allows for faster machining times as well as truly homogeneous free-form surfaces without the need for the manufacturing engineer to repost the NC code.”
Moldmaking programs are noted for their extreme length and complexity, and it’s not feasible for this type of programming to be done manually and verified on the machine control without a way to access the program, he added. “Our built-in Moldmaker feature allows the operator to open the program to get a 3D representation of the toolpath’s wire frame. With this view, the control can help the operator quickly analyze the entire program to see if there are any irregularities to the point cloud distribution. Taking this verification process one step further, we can simulate the entire manufacturing process including 3D material removal without the need of a third-party verification software.”
During the pandemic, Siemens developed a way to support its customers using a tool that had initially been developed for training. The SINUTRAIN software tool allows a machine tool builder, dealer or customer to create a digital twin of the machine, analyze potential problems and troubleshoot or develop a solution before the first cut on the machine. Similarly, Siemens offers a Virtual Product Expert program to set up 60-minute time slots during which they can help customers with operation and programming-related questions or issues, as well as remote training on a new Siemens control.
Meeting Customer Challenges
Ingersoll Cutting Tool Co. (ICTC), Rockford, Illinois, a member of the IMC family of companies, is constantly searching for refinements to meet the challenge its customers face for greater productivity and superior quality in mold-and-die work, according to William Fiorenza, product manager-die mold. Advancements to extend cutting edge life through insert geometries, seating insert design, coatings, grades and edge preps are all aimed at longer tool life and higher material removal rates, he added.
Ingersoll offers a range of milling options for the die-and-mold industry, including indexable tooling options with indexable carbide inserts and solid round cutting tool technologies. “A new, more notable push by ICTC has been to provide customers with much smaller insert IC size offerings for roughing and finishing. New and select existing product lines have been expanded to include smaller insert sizes: 4- and 5-mm insert IC sizes allow indexable tooling design that can achieve cutter diameter sizes as small as 0.25" [6.35 mm],” Fiorenza said.
Benefits of the smaller indexable insert sizes include greater productivity via higher density cutters, reduced tooling costs, and performance enhancements due to reduced cutting forces, he said, adding that they also are cost effective compared to a solid-carbide end mill solution. “These smaller diameter tools, in many applications, deliver higher material removal rates and compare favorably with solid-carbide tools, costing as little as a third of a comparable solid-carbide tool when taking into account the cost of the smaller IC inserts with four indexes and cutter body versus a solid-carbide tool,” said Fiorenza.
The smaller IC insert tools are found in Ingersoll’s DiPosFeed, DiPosDuo, GoldSFeed and HiPosSFeedV families of milling cutters. Available in 4- and 5-mm insert sizes, the smaller IC cutters feature strong insert geometries and clamping, as well as high-feed design features to speed up the milling process and reduce cycle times.
“Today, high-feed tooling advancements leverage that lighter depth of cut to increase productivity even more than in the past,” said Fiorenza. “The new smaller IC sizes have a DOC range from 0.020 to 0.190" (0.5 to 4.8 mm). These smaller diameter tools are ideal for smaller high-speed machining centers, but run equally well on large machines. The smaller IC inserts and the precision machined seating pockets are made possible by Ingersoll’s advanced pressing technologies and precision machining.”
Fiorenza noted that post-pandemic, there is a greater willingness for shops to provide detailed information, when allowed, regarding cutting conditions of their specific applications. Based on his experience, because of the protocols in effect during the pandemic, customers are becoming more receptive to doing virtual meetings because of their experience with Zoom, Microsoft Team or other virtual communications, where various team members can talk one-to-one with other principal personnel in the same session.
“This type of communication and cutting tool technical support process is becoming more widely accepted by our customers, who need to convey and receive information with greater clarity. Being able to interact virtually (remotely) in real time, we can quickly digest and better understand the applications and recommend solutions. These virtual sessions will also help lay the groundwork for subsequent in-person meetings,” he said.
For example, ICTC is working with a larger manufacturer that has been outsourcing its die-and-mold work for many years. It is bringing the work back in-house for various reasons and has reached out to ICTC through its distributor, asking for technical support and training. Initial email communications established a time for a productive virtual meeting that allowed for a clear understanding of the types of product support and training required. As a result, valid tooling options are being provided along with a one-day virtual customer training program that is currently in development, according to Fiorenza.
Connecting Best-in-Class Products
Software is a key tool for building more advanced moldmaking processes, according to Al Whatmough, director of product management–digital manufacturing, for Autodesk Inc., San Francisco. “In terms of design, we’ve got simulation products, like Moldflow, and manufacturing products, like FeatureCAM, PowerMill and PowerInspect. I call these best-in-class point solutions. And then we’ve got some products that I call connective tissue products, like Vault and PLM, connecting the data and the process,” said Whatmough.
Autodesk has developed its Fusion 360 platform to pull technology from its point solutions together so that they can work in connective workflows. “Fusion 360 can be configured for seamless collaboration across an entire product ecosystem of capabilities,” said Whatmough. “That includes advanced milling from PowerMill, automated machining from FeatureCAM, mold simulations from Moldflow or inspection workflows from PowerInspect. It’s a platform for bringing the best of design, simulation and manufacturing together.”
He noted that there’s always a healthy tension between engineering and design. “You can’t really design something without thinking about how it’s going to be made. It is equally important to understand why a product was designed a certain way when manufacturing it,” said Whatmough. “A lot of what we do is trying to better facilitate collaboration between these disciplines to foster a closer working relationship.”
With CAM software for mold work, you can’t program without some element of geometry creation that happens with a subset of CAD, according to Whatmough. This could be surfaces for driving toolpaths or processes of modeling a digital twin of the manufacturing process to ensure safe and collision-free output. To support this work, manufacturing specialists should have access to a complete set of modeling tools, he said.
“For mold-and-die applications, our PowerMill customers want to be sure that the part is a good one before it’s taken off the machine. They want the capability of a tool like PowerInspect,” said Whatmough.
If a part has a defect, that defect must be found before geometry is locked in and the tool is ready to run. Upfront mold simulation provides the capability to see issues earlier in the process and design in manufacturability, so molded parts work right the first time, avoiding an expensive problem, according to Autodesk.
Molding simulation helps moldmakers and other molding professionals understand risks early in the design process. It helps address them before committing fully to the design, giving them accurate digital prototyping solutions and bringing better products to market faster. Moldflow simulation can be paired with other simulation tools, including mechanical stress, vibration, motion, computational fluid dynamics (CFD), and multiphysics.
According to Whatmough, putting an inspection device on the machine may not be a substitute for a final inspection process. However, that inspection device does help validate the part early in the process and saves time that would otherwise be wasted if errors weren’t caught until later.
While faster, better and longer-lasting machine tools represent an obvious improvement, “the more interesting trend is multi-tasking,” said Whatmough. “With moldmaking, we’re talking about a situation where buying a mill that does not include probing is becoming unusual. Equally important, today it seems almost crazy to buy a lathe without at least some live tooling, if not full B-axis milling.” Given that, “to buy a mill without probing seems equally crazy.”
Not too long ago, these would have been options that a shop might second guess, he said. “A lot of it has to do with combining technologies … and that’s becoming the norm. Not to mention that it seems as if every shop in the country has five-axis equipment.”
Looking further into the future, machines that combine additive and subtractive processes are becoming more prevalent. “These new and emerging processes enable generative design to create geometries for cooling molds and can only be made with additive processes,” said Whatmough.