While casting generally guarantees on-time delivery, rare delays do occur. R&DManco, a machining subcontractor located in Phoenix, Arizona, serves numerous well-known clients in the aerospace industry. Its machined parts are certified to relevant standards, including high-precision components used in aircraft fuel and control systems. Machining parts from casting blanks typically has a 32-week lead time. However, if R&DManco can directly machine the precise shape of parts from solid blanks, completely bypassing the casting process, it can typically reduce overall lead times expected by more than 60%, and machining costs generally decrease by 20%. Therefore, R&DManco has set a long-term goal—and has relentlessly pursued it for over a decade—to transition as many parts as possible from casting to pure machining.
Their efforts have also garnered support and encouragement from their clients. One major client frequently includes a clause in some of their machining contracts stating that, if the factory has the capability, they can choose to produce parts using either casting or pure machining methods. Another client of similar size even has a dedicated machining processes team responsible for analyzing the feasibility of converting casting to pure machining. However, not all parts are suitable for machining. For example, a part with a one-year lead time, due to its deep recessed shape, cannot currently be machined and therefore may not be suitable for pure machining. But over time, R&DManco has been able to convert half of the common parts that previously required casting to pure machining.
By bypassing the casting process, customers' supply chains can be further integrated, and factories can take on more business from the supply chain.
John Bloom, president of R&DManco, and Kevin Beach, general manager, both stated that the most important technology for achieving these process transitions is five-axis machining. Bypassing the casting process, complex shapes must be realized using precision form milling.
However, as the trend towards pure machining becomes increasingly apparent, this method is also influenced by more factors, particularly the growing emphasis factories place on related machining operations. When deciding to adopt pure machining methods, factories are not simply adding milling operations; by bypassing casting processes, the customer's supply chain is further integrated, and the factory can take on more business within the supply chain. The factory plays an increasingly important role in determining final costs and parts delivery times. It must bear the full pressure of further cost reduction and shorter delivery cycles. In short, factories adopting pure machining methods are destined to put in more effort.
Therefore, in addition to the machining capabilities of its machine tools, at least two other factors in R&DManco's production approach are also crucial to its continued success in pure cutting processes: the operators and the process technology. For pure cutting processes, the factory is committed to cultivating a corresponding corporate culture and capabilities to achieve the fundamental goal of continuously improving metal cutting rates.
In the past, such parts were machined starting from blank castings. If R&DManco can successfully transform the production process to directly machine parts from solid blank blocks, it will certainly reduce costs and shorten delivery cycles for customers. However, to do this, they are destined to face greater pressure and must put in more effort.
For R&DManco, the most basic capability required for pure mechanical cutting is five-axis machining technology. R&DManco owns six five-axis machining centers manufactured by Haas Automation.
One of the essential secrets to their success in pure mechanical cutting is encouraging experienced mechanical engineers to continuously improve and optimize processes—this has become part of the company culture.
competitive culture
R&DManco owns two adjacent factories, totaling 30,000 square feet, and employs over 70 people. The unusual name comes from the initial merger of the Manco and R&DSpecialty factories. These two factories merged long ago, but the combined name has remained, likely because many employees still remember the process.
“We’ve hired some extremely experienced mechanical engineers,” Mr. Bloom said. Experience is crucial for the factory to successfully leverage the advantages of five-axis machining. The continuous transition from casting to pure cutting means the factory needs to regularly set new process procedures to push beyond original designs and manufacture parts with complex, organic shapes through milling. In developing such machining processes, there is almost always an intersection between theoretical design and practical experience and skills. For example, a five-axis milling cycle that seems feasible in simulations may be plagued by noise or out-of-tolerance precision in actual operation due to inaccurate workpiece positioning, preventing the tool from following specific contours, and so on. In such cases, listening to experienced machining team members can usually help find the most effective way to improve the process and solve the problem in the best possible way.
One of the most important reasons for switching to pure cutting machining is that it can continuously improve machining efficiency.
Company management explicitly emphasized to production staff the invaluable nature of this experience-based judgment. Indeed, continuous process improvements of this kind are significant. After all, one of the most important reasons for switching to pure cutting for a part is its ability to continuously improve machining efficiency. To further leverage practical production experience in continuously improving processes (i.e., increasing the speed and efficiency of metal cutting), the factory intentionally fostered a competitive culture among its employees. In fact, the most obvious manifestation of this culture's impact might not be in five-axis machining, but rather in the factory's 50mm tapered spindle machining center. In this area, the factory deployed large, heavy-duty machining centers to maximize metal removal rates in aluminum and titanium machining. As in other areas, the factory encouraged mechanical engineers and programmers in this field to collaborate on exploring more cutting paths and tooling options to continuously improve the process. The difference with the 50mm tapered spindle machining center is that the machine's machining efficiency can sometimes be significantly improved, especially when machining aluminum. For example, an aluminum part nicknamed "Three Balls" by engineers (named for its shape) could have almost 90% of its initial material removed in the first machining cycle after incorporating several improvement suggestions from employees regarding feed rate and depth of cut. The time required was also reduced from more than eight hours to two hours and forty-three minutes. The driving force behind these improvements was the desire to surpass one's own past achievements, or even (in a positive sense) surpass others.
"When someone breaks free from constraints and successfully innovates, I hope others will also dare to follow suit and break through." — Mr. Bloom (R&DManco)
Of course, many factories are eager to recruit experienced mechanical engineers. However, these highly experienced talents are becoming increasingly scarce. R&DManco faces the same challenge. To bolster its talent pool and anticipate future contributions from its growing experience, the factory has developed an apprenticeship program based on the training courses of the American Die & Mold Association. Three employees are currently enrolled in the program, with more expected to join in the future. A highlight of the program is the starting area for employee training. "At our factory, every employee starts with workpiece inspection," says Mr. Bloom. "That's right, our goal is to continuously reduce processing cycle time and delivery time. To this end, we have also created a competitive corporate culture to encourage employees to strive towards this goal. However, to achieve this goal, it is even more important to first fully understand it. That is, every employee at R&DManco must first understand the standards for qualified parts."
Utilizing machine tool monitoring to control process capabilities
Machine tool monitoring is another crucial factor in R&DManco's success. Collecting basic machine tool status data and analyzing it to diagnose and correct cutting interruptions is one of the most important means for a factory to improve machining capabilities. The connection between workpiece cutting and machine tool monitoring may not be immediately apparent, but in fact, there is a direct link between them. This connection boils down to this: whenever R&DManco bypasses the casting process in the machining of a part, it means breaking through a major bottleneck that once hindered part manufacturing efficiency. The factory can then turn its attention to other new bottlenecks that arise in the pure cutting process.
The first step in implementing machine tool monitoring is to face the reality of machine tool utilization—a figure that was once disappointingly low.
Many of R&DManco's machine tools are purchased from Okuma. The company points out that these machine tools are valuable for implementing machine tool monitoring; using the manufacturer's Windows-based controllers, the system can easily collect real-time status information from the machine tools. For older machine tools or those for which the manufacturer does not provide this open interface, the company has modified the machine tool controllers using MTConnect adapters from ShopFloorAutomations to integrate these machine tools into the factory-wide machine tool monitoring system. Predator's software can integrate this machine tool data, process it, and output it as graphs and reports for subsequent factory analysis.
The first step in implementing machine tool monitoring is to face machine utilization—a figure that has been disappointingly low, according to company managers. Almost every factory makes the same mistake regarding effective cutting time: their subjective estimates are longer than the actual cutting time. However, understanding actual machine utilization is extremely helpful, even if the figure may be disappointing, Mr. Beach says. First, this metric allows factories to understand their actual processing capacity. Enterprise Resource Planning (ERP) software used for production planning may not know this, which is why parts are still delayed even when production plans are in place in the ERP system. Understanding actual capacity allows factories to know when to outsource operations to compensate for insufficient processing capacity. Second, understanding actual utilization allows factories to see potential for improvement and then work to tap into that potential.
This work wasn't necessarily simple, but we didn't intentionally complicate it. "When we first started implementing machine tool monitoring," Mr. Beach said, "all sorts of identification codes popped up, indicating why the machines were stopping." The computer screen became a colorful palette, displaying the various reasons identified (or perceived by the software) for machine tool stoppages. "The reasons were dazzling, but not very valuable," he said. The analysis data on machine tool non-cutting time he obtained didn't explain what was actually happening on the machines well. Instead, he realized that, in reality, "non-cutting time is just non-cutting time, nothing more." In any case, if a situation occurs too frequently, the cause should be identified and addressed. Today, the factory's machine tool monitoring system can describe all activities of all machines using three states instead of two (cutting and non-cutting). One cause of production delays proved to be quite significant and worth recording and monitoring.
Practice has shown that the waiting time for first-piece inspection is the most important reason for factory production interruptions.
The reason is first-piece inspection. Experience has shown that the waiting time for first-piece inspection is the most significant cause of production interruptions in the factory. This discovery may be one of the earliest major achievements of implementing machine tool monitoring. After understanding the problem, the factory took various measures to solve it. The quality control department added a coordinate measuring machine and a technician specifically responsible for first-piece inspection. Furthermore, R&DManco is exploring the possibility of performing first-piece inspection without the workpiece leaving the machine tool. Using Renishaw's "Productivity+" software, the machine tool itself can measure the workpiece using a probe and compare the measured values with the original CAD file data. Some workpiece types have been successfully converted to this method of first-piece inspection, eliminating the need to send the first finished part to the quality control department for inspection, thus completely avoiding production delays.
Chris Dupre, the CNC milling manager, described the initial problems affecting the stability of the workpiece positioning during mechanical cutting.
General Manager Kevin Beach showcased a part nicknamed "Three Balls" by engineers (due to its shape). Weighing approximately 4 pounds, it was machined directly from an 80-pound block of aluminum blank. A 50-inch tapered spindle machine, operating at high speed (typically with a spindle load of 110%), can reduce the milling cycle of the part from over eight hours to less than three hours.
Other achievements of machine tool monitoring
Mr. Bloom and Mr. Beach pointed out various other findings regarding improved processing efficiency obtained through machine tool monitoring at the factory. These findings wouldn't have been grasped so quickly by factory management had the monitoring data not made them clearer. R&DManco summarized their experience as follows:
1. Horizontal machining is not only suitable for certain workpiece types but also ideal for some machining processes. The factory installed a horizontal machining center with six exchangeable tables in 2017, but its initial utilization rate was not ideal. Mr. Bloom believes the problem was that the factory primarily considered the machine's machining capacity. The factory assigned machining jobs to this horizontal machining center because it could effectively utilize four axes. While this approach was good at the time, focusing solely on machining capacity overlooked the fact that the machine's productivity actually depends on the number of machining jobs the operator can set each day. For horizontal machining centers, the most suitable machining jobs are those that retain their initial settings due to the repetitive nature of the machining. Therefore, while the factory initially considered machining capacity when assigning jobs to the machine, it now comprehensively considers factors such as machining capacity, order quantity, and whether the job is a critical part of ensuring consistent contract execution to rationally allocate machining tasks.
2. The challenge of handling large workpieces is a major factor limiting production efficiency. For example, in a dual-machine machining unit, if the workpiece being turned is too large to be handled manually, digital analysis of the machining performance reveals that purchasing a low-tech hardware device can significantly improve overall machining performance. When the factory discovered that moving a workpiece from one machine tool to the other in the machining unit took longer than expected, they installed a gantry rail system on a crane specifically designed to serve both machines, thus solving this efficiency problem.
3. Regarding the utilization rate of the seven-axis turning machining unit, one statement is correct. To perform the most complex turning operations, the factory established a turning machining unit consisting of three seven-axis turning centers. Given the high degree of automation of these machines—completing the machining of an entire workpiece in a single milling cycle—most people believe that one operator is sufficient to manage the production operations of all these machines. However, some disagree; dissenting voices within the factory management argue that two operators are actually more reasonable for the machining unit. This debate may continue indefinitely until the machine tool monitoring data provides a definitive conclusion. The practice of assigning two operators to this position is correct. The machine tool utilization rate of this machining unit is the lowest of all equipment in the factory (its utilization rate should ideally be the highest), and increasing manpower significantly improves the unit's machining efficiency.
R&DManco now has an employee dedicated to summarizing more production experiences of this kind, and its manufacturing engineer, Luis Hernandez, has been appointed as the head of the company's continuous improvement team. The conclusions drawn from the aforementioned investigation and analysis have significantly improved the utilization rate of factory equipment, and the resulting potential returns undoubtedly justify the formation of this team. The company states that a role like Luis Hernandez is essential because the root cause of a production interruption at any given moment is not always obvious and may be the result of multiple factors working together. In fact, Mr. Hernandez is not working alone. Part of his job is to listen to the ideas and opinions of others and to discuss machine tool processing interruptions in depth with team members in order to identify possible causes and solutions. He said, "In the past, I mainly communicated with the engineering department; now I communicate more with the shop floor foremen. Next, I will discuss the data with the mechanical engineers themselves, hoping to identify the processing delays that are hindering their work."
Mr. Bloom concluded by pointing out that this approach of analyzing data and improving efficiency is equally applicable outside the production line. He said it also applies to office work, such as reporting production plans to clients. Even before implementing machine tool monitoring, the company recognized the importance of regularly analyzing and summarizing completed work from the perspective of "comparing our pre-reported data with our actual performance." He emphasized this point. One recent lesson he learned was that the company was too aggressive in reporting steel production plans. In reality, the actual processing speed of steel parts could not meet the factory's pre-set production schedule. The process in this area may need improvement, but currently, by lowering the expected cutting rate when formulating production plans, the accuracy of steel production reporting has improved.
When a customer inquires about the status of an incomplete production order, the company often finds that by the time all the information needed to answer the question has been collected, the answer may already be outdated.
In fact, the process of simply obtaining this necessary information is inefficient and time-consuming. He said Mr. Bloom realized this about seven years ago. When customers inquire about the status of an incomplete production order, the company often finds that by the time all the information needed to answer the question is fully gathered, the answer may already be outdated. The information is too scattered and covers too broad a range.
At the time, he collaborated with a software developer to create a software he called "GrandView," which could quickly provide enough information to answer customer inquiries. Some of the data needed by the software could be found in the factory's ERP system, while others could be found in local spreadsheets. In other words, this custom utility integrated data from multiple different systems. He said that after using it for a while, he began to realize how useful this unified view tool was, not only for answering customer questions but also for helping him better understand the various reasons that caused production disruptions and for assisting in monitoring the factory's increasingly complex processes—especially with increasingly stringent delivery deadlines.
In the past, machining operations, primarily involving the cutting of castings, rarely required the extensive process control seen today. Regardless of a factory's production capacity, the waiting time for castings to complete resulted in lengthy finished product delivery times; the factory could only begin machining after receiving the castings. Today, the situation is different. Now, in many cases, R&DManco has complete control over production operations from start to finish, and the company is fully accountable for its commitments to shorter lead times and on-time delivery. This increased responsibility necessitates more comprehensive production monitoring, so Mr. Bloom improved his GrandView utility to meet this need. By querying the ERP system's database to extract the machining cycle time of a workpiece, the custom utility now automatically calculates and reports to management the latest time when machining of the workpiece must begin to ensure promised delivery times are met. By querying the factory's digital inventory records, the utility can now also indicate whether inventory is sufficient or needs replenishment.
These are all important pieces of information that are easily overlooked. For factories that integrate more links in their customers' supply chains into their own operations, one requirement is that they must have an increasingly sophisticated system that keeps information clear and easy to access, so that the progress of work is still clear at a glance, even when the factory is busy.
