Abrasive waterjet machining technologies promise fast, clean cutting with high-pressure waterjets approaching 100,000 psi (689 MPa.) Abrasive waterjets give manufacturers a cold-cutting process that cuts thick sheet metal, granite, and many other hard materials with no heat-affected zone (HAZ) to compromise the workpiece material integrity.
Some of the latest abrasive waterjets on the market add new software intelligence that helps users easily monitor and calibrate machining performance with new, more reliable machines that offer better uptime. Faster cutting processes on the new systems also enable builders to dramatically cut cycle times and costs, thereby improving overall productivity.
Today’s abrasive waterjets typically boast high-pressure pumps that can easily reach 90,000 psi (621 MPa) or higher for speeding up the cutting process and improving job shops’ part cycle times.
Abrasive waterjets are used to quickly and accurately cut a wide range of parts, from large aerospace and automotive metal components to stone and granite, as well as smaller parts with tiny feature sizes needed in tools, implants, and medical devices. Waterjet technology choices include machines cutting with water only, which are used for cutting soft materials like rubber, foam, plastics and composites, and those that cut with grit added, such as from garnet or other abrasive elements. Added abrasives enable the water stream to slice through the hardest of metals and other materials. Waterjets can cut workpieces up to 20" (508 mm) thick with high precision, holding tolerances of +/-0.001 to 0.005" (0.025–0.127 mm). With no HAZ, they leave no recast layer on heat-sensitive components.
The issues facing waterjets are similar to those affecting other types of machine tools. “The trends that drive developments at OMAX are understanding the difficulties in hiring qualified employees, the challenging economic environments across the globe, and the evolution in digital manufacturing,” said Mike Ruppenthal, general manager for Kent, Wash.-based waterjet builder OMAX Corp.
Ruppenthal pointed to his company’s GlobalMAX line as an example of a waterjet machining system that is more accessible to a wider range of manufacturers looking to incorporate waterjet machining technologies into their shops.
“The GlobalMAX line offers all the benefits of cutting with waterjet at a price point that is more favorable to fabricators who are new to waterjet or who would like expanded capabilities without larger capital investment,” he said. “Waterjet operators are usually looking for three things: predictability, reliability, and ease of use.”
There is a growing need in manufacturing for more advanced applications, noted Kurt Mueller, director of global product management, for waterjet builder Flow International Corp., Kent, Wash. “Waterjet technology’s versatility is a key reason why it’s becoming a large part of the advanced applications industry,” Mueller stated. “Waterjets provide capabilities to cut materials like composite and advanced aerospace alloys, expanding the type of materials a manufacturing shop can process.” The industry seems to be turning to technology with 3D cutting capabilities to broaden the range of potential applications.
“Manufacturers are looking to invest in technology that provides business flexibility, and this is where waterjet shines,” Mueller added. “Waterjets are advancing to be faster, more accurate, and less expensive to operate.” For most shops, faster cutting results in higher throughput; better accuracy means they can tackle more applications with tighter accuracy requirements; and equipment that is less expensive to operate means a better return on investment.
The industry is also shifting from away from the break-fix mentality, he noted. “Manufacturers want to increase uptime and rely on more predictable maintenance for their waterjet systems,” Mueller said. “The constant focus on efficiency allows a smoother running operation, less downtime, and more time to focus on business.”
Efficiency and intelligence are key trends driving waterjet technology today, said Jim Fields, national sales manager, Techni Waterjets, Charlotte, N.C. “It’s about quick diagnosis of problems, how to fix [them] and taking the subjectivity of the operator out of the maintenance equation. Uptime is key to productivity. So the more we minimize downtime and maximize reliability, the more productive and profitable our customers become.”
Waterjet users have several key priorities to improve and optimize waterjet technology, said Arion Vandergon, marketing manager for Hanover, N.H.-based Hypertherm Inc. “In rough order of priority, these include improving cutting speed, abrasive and water utilization and management, predictability and length of maintenance intervals and downtime, reducing total cost of ownership, improving serviceability, reducing capital cost, improving ease of use and ease of setup, and increasing energy efficiency,” Vandergon said.
As with most of the manufacturing industry, software plays a vital role connecting factory-floor machines in the age of Industry 4.0, and more emphasis is being placed by all waterjet makers on building connected systems that can improve all aspects of waterjet machining. Flow sees a significant part of the industry’s growth in software and connectivity, Mueller said.
“Connected machines will supply data ranging from predictive maintenance intervals to optimized machine operation for specific jobs or classes of jobs to a continually improving cutting process,” he stated. “Linking the data generated from running the machine will improve the efficiency, accuracy, and reliability of waterjet systems.” The impact of this efficiency enables customers to increase production and produce better quality parts while simultaneously improving the reliability of their manufacturing process.
Flow introduced five-axis technology with the design of its Pivot+ Waterjet. It also made advancements to true 3D cutting capabilities with its Dynamic XD. “To optimize the cutting experience, we developed tools for height sensing and contour following for Flow cutting heads,” siad Mueller. It is also known in the industry that taper is inherent in all waterjet cutting. Through software and hardware, Flow offers proprietary technology for taper elimination. Flow’s lineup spans the range of systems in the industry, Meuller noted, offering a selection of end-to-end waterjet cutting solutions, from standard and 3D cutting systems, to integrated and engineered-to-order solutions.
OMAX’s software controller, IntelliMAX, facilitates machining in a way that provides high accuracies and rapid cutting times, according to Ruppenthal. “IntelliMAX is a user-friendly software that allows many first-time users to become proficient very quickly,” he said.
Part of the IntelliMAX software suite is the IntelliVISOR program. “With the IntelliVISOR System Monitoring Package, you can increase efficiency and reduce downtime by connecting operation controls with machine maintenance and upkeep,” he said. “While our machines support MTConnect, IntelliVISOR goes much further by integrating real-time cutting data from different devices across the OMAX or MAXIEM JetMachining Center through its streamlined software interface and robust machine sensor network.”
The software element is critical with the advent of newer applications, such as smaller parts, even micro-sized parts that customers are tackling with the latest waterjets. “We’re always amazed at what our customers are doing,” said Ruppenthal. “In more than one instance, our ProtoMAX customers are cutting intricate custom pieces for the auto industry, while others are using the personal abrasive waterjet to build their Etsy (web-based) business. It’s very exciting.”
Another application for OMAX waterjets is in composites manufacturing. Since a waterjet doesn’t impart HAZ or further material distortion, new and experimental composites are often machined via waterjet, he noted.
Flow’s waterjet software offers features such as taper control, cornering models, part accuracy, and defined finish, noted Mueller. “Our software showcases a large library of characterized materials. The software allows users to automatically adjust the cutting model to optimize for a variety of material types,” he said. The company’s software solutions include operation, programming, 3D cutting, capabilities to import file formats, and a CAD interface. “We also offer true 3D CAD capabilities with our FlowXpert software,” he said.
An important aspect of waterjet evolution is software-based, he added. “By employing modern software design principles, Flow is developing a new, more intuitive user experience allowing a faster user ramp-up, less need for waterjet-specific expertise, and significantly more flexibility for automation of the workflow.” One intent is to integrate waterjet technology into multi-process production environments, bringing waterjet processing to new markets.
Flow’s entire line of waterjet cutting systems, with the right combination, can cut applications from smaller, micromachining prototypes to larger format, multi-head productions, according to Mueller. “Our customers are cutting unique applications from composite and hard-to-machine materials in aerospace, to a variety of metal types and thicknesses in job shops. We also have customers that utilize robotic waterjet applications in cutting, cleaning, processing, and automation.”
Hypertherm has incorporated several software routines in its Predictive PLC to simplify the operation of the company’s waterjet pumps, according to Vandergon. “These routines include an optimized startup routine, post-maintenance startup routine, and a fully automated proportional pressure control calibration routine,” Vandergon said. “Users no longer need to remember steps when starting or stopping the pump. The user simply needs to press the start button and the pump will automatically start and build pressure using the optimized routine.” This routine provides consistent performance and protects key components in the system to maximize consumable life.
In addition, Hypertherm recently launched a waterjet cutting calculator (downloadable on its web site) that Vandergon said provides users with a simple tool to view cutting speeds and pierce times for a variety of materials. Users can select their pump model, edit operating costs, edit or add material, and adjust cutting parameters (orifice/nozzle combination, abrasive flow rate, cutting and piercing pressures). The calculator results provide the cost per inch, cost per hour, pierce time (both static and dynamic pierces) and the cutting speed for the parameters selected. The calculator, also available as a mobile app on both iOS and Android platforms, helps remove the guesswork associated with setting up a new job or cutting a new material, according to Vandergon.
Techni’s Fields said the company’s software is bundled in one module that makes it quick and easy for users to make changes on the fly. “This avoids the confusion of going in and out of multiple modules where something can be missed along the way. An example would be if I make a change in my object (DXF) file, the change migrates out through the nest instantly,” said Fields. The conventional way involves several steps: making a change to be made in the CAD package, then re-processing parameters in the CAM package, and then sending it back out to the nesting package. “[Our process] avoids a lot of steps and opportunities for human error,” he said.
Software improvements partly enable waterjets to tackle newer applications. “There are definitely new applications. I always say ‘the imagination is the biggest limitation with waterjet,’” said Fields. The technology can handle applications both small and large. “The micro-type apps continue to grow as we control process parameters more closely, but the larger, thicker-type applications are also growing as cutting pressures go up and efficiencies get engineered into the overall system,” he said.
Improving productivity requires deploying smart, efficient waterjet machines with innate intelligence built into the system that help remove the operator from the equation, noted Fields. Techni is a leader in lights-out (un-manned) waterjet operation, having released its Tech-Sense technology back in 2002, he stated. “This allows real-time feedback and machine feed holds when a cutting parameter is outside a preset bandwidth, so it does need not an operator to tell you when something is worn or garnet has stopped flowing. The machine does it for you.”
In 2016 the company released the first version of its ADK (Advanced Diagnostics), which he claims closes the loop on un-manned operations. “With ADK, operators can reliably leave the machine to run on its own,” said Fields. “This feature monitors everything pump-related. We continue to expand its capabilities through the on-board intelligence built into our pumps.”
Waterjet machinists rank machine reliability and ease of use very high on their lists, he added. “Reliability comes to mind first and foremost, then ease of maintenance. You want a machine working for you, not a machine you have to work on.” The company’s pump design, Electric Servo Pump (ESP), allows for a seal change in less than 15 minutes, according to Fields.
Operators are looking to simplify the waterjet cutting process, according to Vandergon. “While waterjet is gaining in popularity in the cutting industry due to its wide capabilities, it has earned a reputation as being maintenance-intensive and costly to operate,” he said. He believes machine owners are looking for more automation and predictability out of their equipment to streamline operations and plan for preventative maintenance.
“Hypertherm and our channel partners work with customers to optimize their setups and improve productivity. The seal life predictability provided by Seal Maintenance Technology results in the ability to plan preventative maintenance activities when the workload allows, rather than losing precious cutting time waiting for parts to arrive or service to be carried out.”