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Advanced CNC Machining – Current Scenario and Emerging Trends
Advanced CNC machining will become a critical pillar of smart manufacturing, enabling flexibility, efficiency, and precision, says Milton D’Silva.
CNC simulation software helps manufacturers avoid errors. Image credit: Hexagon
Machine tools are used to shape, cut, or finish parts made of metal or other materials. They are essential for producing a wide range of components, from consumer goods to automobiles, aircraft and spacecraft and parts for other machines. Machine tools form the core part of the manufacturing process of the products in daily use.
Machine tools have evolved over several millennia with records suggesting use of bow drills to make holes in wood and stones by ancient Egyptians, Greeks and Romans in the BC era. These civilisations had also developed the early lathe, operated by two persons, where one person turned the wooden work pieces while the other worked on it with a sharp tool. Such lathes were used to make a variety of objects like containers and furniture parts. Later more advanced tools like water mills and hydraulic presses evolved. All these tools were mostly manually operated, though later horse drawn boring machines were used to fabricate canons. Rapid advances in machining operations were made during the Industrial Revolution that began in the late 18th century with the invention of the steam engine that led to other machines like the spinning jenny and milling machine. These tools, driven much faster by steam power boosted both power and efficiency, and thus began the era of mechanised machine tools.
The development of cast iron beds and slide rests further improved the accuracy and reliability of the machining process, making the lathe truly ‘the mother of all machine tools’. Steam power was later replaced by electric motors by the late 19th and early 20th century as the lathe continued to evolve, improving both speed and precision. From here to semi-automation and further full automation was a relatively short journey, and by mid-20 century, a numerical control (NC) system was introduced with punch cards to control machining operations. The NC system was soon coupled with computers which ushered in the CNC era, with full automation of the operation, raising accuracy to a new high and bringing in complex geometries in parts manufacturing.
Incidentally, this evolution of machine tools happened in tandem with the rapid advancements in the automotive, aerospace, white goods and medical equipment industries. The high precision requirements of these industry segments for intricate parts with complex geometries called for specialised machining capabilities. This in turn pushed the boundaries of innovation in the machine tool industry, spurring mutual advancements in technology, aiding the growth of both segments. To cite just one example, the increased fuel efficiency of modern automobile engines has been largely facilitated by CNC machines that enabled the production of lighter, more efficient, and better-performing components – engine blocks, cylinder heads and differential cases – and vehicle structures. This article explores the current state and future direction of advanced CNC machining.
A visitor checking a latest CNC machine model at TIMTOS exhibition, Taiwan. Image credit: TAITRA.
Current scenario of CNC machining
The contemporary scenario in CNC machining is far removed from the early days, with machines now increasingly automated, digitised, and integrated with smart manufacturing systems. Advanced CNC technologies like 5-axis machining, robotics, AI-driven process optimisation, and digital twins are becoming more common, especially in high-precision industries like aerospace, medical and automotive. However, adoption is uneven, with SMEs lagging due to cost, skill gaps, and integration challenges. The push toward Industry 4.0 and customization is accelerating demand, but widespread adoption still faces notable barriers.
The state of the industry
Necessity is the mother of invention. This well known proverb perhaps has more relevance to the machine tool sector than any other, as all important innovations like numerical control happened as a response to the demands of the industry. The 20th century is known for giant strides made in automobiles, aviation and aerospace, shipping and transport, nuclear energy, the white goods revolution and the medical equipment industry, each having its own set of demands for machining – the art of cutting metal to suit specific requirements. The machine tool industry on its part rose to these challenges admirably, literally providing the cutting edge. Compared to other industries, the digitalisation of the machine tool industry began quite early, in the 1940s with the NC system and progressed further with CNC machines. Further developments like integration of CAD/CAM, PC-based open architecture controllers, use of sophisticated software for advanced machining operations followed.
According to Fortune Business Insights, a leading market research agency that also provides end-to-end solutions beyond flagship research, the global CNC machine tool market size was valued at USD 95.29 billion in 2024. This is projected to grow from USD 101.22 billion in 2025 to USD 195.59 billion by 2032, exhibiting a CAGR of 9.9% during the forecast period. The remarkable market growth is propelled by the healthy demand for more automation and precision in the manufacturing industries. Key sectors driving demand today are automotive, electronics, aerospace & defense, power & energy, construction equipment, and medical devices. The massive infrastructure growth in developing countries as well as growing emphasis on decarbonisation of energy are the leading drivers.
Common CNC machine tools
Apart from the ubiquitous lathe that remains as popular as ever as the most basic machine for any workshop, common CNC machine tools are turning, milling and drilling machines, grinders, plasma and laser cutters, waterjet cutters, electric discharge machines (EDMs), etc. The EDM is not a traditional metal working machine, but a machining process that uses electrical sparks to remove material from a workpiece. Then there are various types of metal forming machines like CNC press brakes, hydraulic bending machines, punch presses and plate rolling machines, also in extensive use. For the record, machine tools today are broadly classified in two groups – metal cutting machines and metal forming machines. Cutting machine tools remove material from a workpiece by shearing or chipping, while forming machine tools reshape the material by bending or pressing, without cutting or removing any of it. Among the leading global manufacturers of advanced CNC machine are well known brands like DMG MORI (Germany & Japan); MAZAK (Japan); MIKRON (Switzerland); MAKINO (Japan); CHIRON (Germany); Okuma (Japan); Hermle (Germany); GROB (Germany); YASDA (Japan); Haas Automation (USA); EMAG (Germany); Doosan (Korea); Matsuura (Japan); Starrag (Switzerland); and Hurco (USA). Apart from these, there are hundreds of other manufacturers. Speaking of countries with large volumes of machine tool production, China, Taiwan, Italy, Spain, and India figure among the leading manufacturers.
Launch of the Mazak Integrex i-630V/6 AG multi-tasking machine at EMO 2023. Image credit: Rainer Jensen/VDW
Multi-axis machines
A significant aspect of modern machine tools is the development of multi-axis machines. Traditionally, CNC machines worked only in three axes – x, y and z – representing linear movements. Together, these movements – left to right (x), front to back (y), and up and down (z) – are enough for most machining applications. However, for parts with complex geometries required for aerospace and medical applications and also in modern automotive components, the 3-axis machines are inadequate and hence multi-axis machines were developed that offered additional rotational axes. Apart from the ability to produce complex shapes, multi-axis machines – 5-axis machines are today commonly used – also provide increased accuracy and faster production speeds with reduced setup times.
Another area where contemporary machine tools have achieved great success is improvement in high precision, high accuracy and repeatability, attributes that matter most in machining parts with sub micron tolerances for demanding applications in aerospace and other industries. This is also aided in no small measure by the integration of CAM software and simulation tools, as well as advanced measuring instruments like Coordinate Measuring Machines (CMMs), laser scanners, and digital micrometers.
Operational improvements
Unattended machining today is no longer a fantasy with robotic loaders, bar feeders, and tool changers allowing 24/7 machine operation. At the moment though there are human supervisors overseeing operations in such automated workshops, lights-out machining is a reality at many manufacturers, the most notable example being FANUC, the company operating its own factory on the lights-out model since 2001. Several other leading machine tool manufacturers are also known to operate their third shift – the most unpopular among human workers – as light-out shift.
The other improvements are IoT-enabled monitoring where sensors capture data like spindle loads, vibrations, and tool wear. Platforms like MTConnect and OPC-UA help standardise data for analytics. With automated inspection, on-machine probing and in-process metrology reduce scrap and ensure dimensional accuracy.
AI generated image of a CNC machine producing a component with intricate design. Image by Freepik
Emerging trends in advanced CNC machining
With advanced CNC machining the following trends are now emerging in the manufacturing space:
Integration of Smart Manufacturing & Industry 4.0
With the advent of Industry 4.0 and the concept of connected machines, CNC machine tools have now progressed into the advanced automation era. Connected machines or Cyber-Physical Machine Tools (CPMT). These machines, equipped with sensors, embedded computers, and network connectivity, integrate computation with physical processes, allowing monitoring, control, and even autonomous operation of CNC machines. Two or more machines now combine to form cells for specific purposes like production of alloy wheels for cars, the machines tended by robots and monitored by AI to oversee seamless integration with automated inspection equipment and image processing technologies. These machines now move effortlessly from mass manufacturing to mass customisation for a hypothetical production run of a single part, one of the basic attributes of the Industry 4.0 ecosystem of smart production.
Predictive Maintenance
One of the significant advantages connected CNC machines bring to the table is enabling predictive maintenance using machine learning by algorithms. The data gathered by sensors of various parameters – temperature, vibration and power consumption – can yield valuable insights on the actual running condition of machines. This is assisted in no small measure by the use of digital twins and simulation. These virtual replicas of physical assets allow real-time monitoring, data analysis, and simulation of various scenarios to predict potential failures and optimise maintenance strategies. This enables proactive maintenance, reduces downtime, and improves asset performance. By addressing issues early, the cost of repairs and component replacements is reduced. Predictive maintenance also ensures machines operate at peak performance for longer periods.
Hybrid Machining – Additive + Subtractive
Perhaps the most interesting trend now emerging in CNC machining is the combination of additive and subtractive technologies into hybrid manufacturing. While traditional machining is subtractive – removing metal from a solid block to get the desired shape, additive manufacturing actually deposits layers of substrates to form a component. The additive + subtractive hybrid machining (ASHM) is ideal to create parts with complex geometries and high precision used in aviation and medical industries. The process overcomes the limitations of each individual method by utilising the advantages of both. For example, a 3D printed part can be subsequently machined to improve surface finish, dimensional accuracy, or to create internal features that are not easily achievable through additive manufacturing alone. More importantly, ASHM can minimise material waste compared to traditional manufacturing techniques. In some cases, it can lead to faster production times by leveraging the rapid prototyping capabilities of additive manufacturing and the precision of subtractive processes.
DMG MORI and Siemens presented the first end-to-end digital twin for machine tool machining on Siemens Xcelerator. Image credit: Siemens
Artificial Intelligence and Machine Learning Applications
Among emerging technologies, Artificial Intelligence and Machine Learning (AI & ML) are the real game changers. Besides helping in predictive maintenance, AI & ML are instrumental in optimising automated toolpaths with real-time parameter adjustments. AI can analyse vast amounts of data to identify patterns and trends, providing data-driven insights for process optimisation. While AI helps automate post-cutting quality inspections to ensure dimensional accuracy and surface finish faster than what is humanly possible, ML algorithms can be trained on historical data to improve the accuracy of CNC machining processes. Besides, AI-powered CNC systems can adapt to new designs and materials with minimal human intervention, making them more flexible and adaptable to changing production needs. AI optimises workflows by analysing data and adjusting machine parameters in real-time, leading to faster production cycles and reduced errors. ML helps by analysing the datasets and then saving for future references, eliminating the need to repeat the process for every cycle, every time. Together, these technologies enhance CNC processes by learning from vast datasets, enabling more dynamic and adaptive workflows, and ultimately reducing waste, production time, and operational costs.
Advanced Materials and Tooling
It is not just technologies that are ushering in revolutionary changes in CNC machining. Advanced materials and tooling are also playing an important role in this revolution by facilitating the production of more complex and precise parts, while also improving efficiency and reducing costs. It is now possible to use high-strength steel and aluminium alloys, and hard-to-machine metals like titanium alloys thanks to a combination of high speed and high precision machining in combination with advanced cutting tools with high performance coatings. Tools made of carbide or ceramic, and coated with various materials like titanium nitride (TiN), titanium carbonitride (TiCN), aluminum titanium nitride (AlTiN), and diamond-like carbon (DLC), are ideal for high speed machining. These tools not only offer superior wear resistance and heat tolerance, but also extended tool life and improved machining efficiency. Besides, the development of new cutting tool geometries and materials allows for faster machining speeds and more complex part geometries. Further, emerging technologies like sensor-equipped tools enable real-time monitoring of tool performance, allowing for predictive maintenance and optimised machining parameters. All these innovations are driving precision, accuracy, and scalability in various industries, including aerospace, automotive, bio-medical and beyond. Also used now are various composites like carbon fibre reinforced polymers (CFRP) which are lightweight, with high strength and durability, making them ideal for aerospace and automotive applications.
Human-Machine Collaboration and Skills Evolution
Amidst the evolution of technology, there is the constant and all important human element for which there is no substitute. Technology is after all produced by human intelligence and efforts, a constant endeavour to make things better. The human-machine collaboration allows for a more integrated approach, where human expertise and machine capabilities are combined to optimise the machining process, ultimately leading to improved productivity and product quality. By leveraging human expertise and machine automation, the collaboration between humans and machines optimises the machining process, leading to increased productivity and higher output. The synergy between human creativity and machine capabilities fosters innovation and problem-solving in the machining process, leading to the development of new techniques and approaches. As humans and machines collaborate, the skills of machine operators evolve to include a deeper understanding of machine capabilities, data analysis, and programming, allowing them to work more effectively with the advanced technology.
Lights out manufacturing for high-mix, low-volume prototyping with robotic automation. Image credit: FANUC
Entry barriers and challenges
With all the advantages highlighted above, advanced CNC machining – technologies like 5-axis machining, multi-tasking machines, automation, and digital twins – ought to be widely adopted globally in quest of better quality and high efficiency of every product manufactured. However, in reality, this is easier said than done. Their widespread adoption faces several entry barriers and challenges despite the potential to revolutionise manufacturing. What exactly are these challenges is briefly examined point by point in the following paragraphs.
1. High Capital Investment – the very first obstacle faced in any new technology adoption globally is the cost, which obviously is high initially. Advanced CNC machines and associated automation (robots, sensors, AI software) are expensive and the return on investment is the first thing that presents itself as a barrier. While large corporations may not face this problem, many small- and medium-sized enterprises (SMEs) that are significant players contributing to manufacturing output, struggle to justify or secure funding for the initial investment.
2. Skills Shortage – A lack of qualified personnel who can program, operate, and maintain advanced CNC systems. This is more so given the penchant of young engineers today to prefer the services industry with better earnings than the manufacturing sector. As a result, the workforce often lacks training in areas like CAD/CAM integration, G-code customisation, 5-axis kinematics, and system diagnostics.
3. Complexity of Technology, Long Learning Curve – Integrating CNC machines with ERP systems, IoT platforms, and AI-driven analytics requires significant expertise and customisation, as well as new workflows and process re-engineering. The main challenges manufacturers face are difficulties with data standardisation, real-time connectivity, and cybersecurity. The inherent tendency of the workforce to resist change adds to the fear of obsolescence.
4. Limited Interoperability and Vendor Lock-In – A serious concern shared by many entrepreneurs is the complexities that arise from having machines from different manufacturers and their proprietary software and interfaces. This limits flexibility and increases long-term costs due to dependence on specific vendors for upgrades and maintenance. Add to that the supply chain and tooling dependencies, and the problem of spare parts that may not be locally available, adding to delays in implementation or increased OPEX.
5. Maintenance and Downtime Risks – Advanced machines have more components and sensors, increasing the risk of technical failures if not properly maintained. This again relates to the lack of adequate skills mentioned earlier. The challenge is the unplanned downtime can be costly and impact production schedules severely.
6. Data management and system integration complexities – CNC machining involves complex interactions between hardware, software, and data systems. Integrating machine data with MES, ERP, or PLM systems is difficult without standardised protocols. Inconsistent formats for toolpath data, machine logs, or maintenance reports create compatibility issues.
7. Regulatory and Compliance Issues – In sectors like aerospace or medical devices, any change in manufacturing technology must be validated and certified. The time and cost of re-certification can deter innovation apart from delaying project execution, adding to costs.
8. Cybersecurity Concerns – The elephant in the connected ecosystem room today is cybersecurity. CNC systems integrated with the cloud or IoT are vulnerable to cyberattacks. The challenge here is to be a step ahead of hackers and cybercriminals. Ensuring secure data transfer, remote monitoring, and protection against malware/ransomware is an ongoing concern.
Future Outlook
Given the rapid pace of evolution of breakthrough technologies, what is the future outlook for the machine tools industry in general, and advanced CNC machining in particular, in the world of manufacturing?
The future of advanced CNC machining not only looks promising, but with its role expanding significantly as part of the broader Industry 4.0 transformation, it is also going to play a significant role in the emerging sustainable manufacturing ecosystem. The following are the key trends shaping this outlook:
1. Cryogenic machining and minimum quantity lubrication (MQL) – Cryogenic machining uses extremely cold liquefied gases, like liquid nitrogen or carbon dioxide, as a coolant during machining to reduce heat and improve tool life. Minimum quantity lubrication (MQL) uses a small amount of lubricant, often atomised and delivered with compressed air, to reduce heat and improve lubrication in the cutting zone. Benefits include increased tool life, especially in hard materials, higher material removal rates. Also uses a minimal amount of lubricant, often delivered as an aerosol with compressed air, to lubricate the cutting tool and workpiece. This approach can improve lubrication and cooling capabilities, potentially leading to better machining performance, especially for difficult-to-cut materials.
2. Greater Automation and Autonomy – Already at the peak of advanced automation, CNC machines will become increasingly self-optimising and autonomous, integrating AI for real-time process adjustments, error correction, and adaptive toolpaths. The age of next generation AI-native, self-learning machines is not too distant now.
3. Full Digital Integration – In line with the emerging industrial metaverse, seamless integration with digital twins, IoT platforms, and smart factory systems will become the norm in the world of CNC machining. This will in turn further fine-tune the already prevailing trends of predictive maintenance, remote monitoring, and simulation-driven machining.
4. Customisation and Agile Manufacturing – CNC machines will play a central role in low-volume, high-mix production to meet the demand for personalised products and rapid design-to-part cycles. The future is in moving beyond mass production to the era of mass customisation.
5. Widespread Use of Advanced Materials – In the quest of energy efficiency and decarbonisation, CNC machines will increasingly handle composites, ceramics, and exotic alloys, driving innovation in aerospace, medical, and automotive sectors.
6. Democratisation via Cloud and AI – Cloud-based CAD/CAM software and AI-assisted programming will lower entry barriers for smaller manufacturers, making high-precision machining more accessible. This will also be supplemented by Machining as a Service (MaaS) – a cloud-based, on-demand manufacturing model where customers outsource their CNC machining needs to a network of service providers, rather than investing in their own machines or facilities.
7. Sustainability and Energy Efficiency – Future CNC systems will focus on energy-efficient operations, minimal waste, and circular economy principles, aligning with green manufacturing goals.
8. Collaborative Robotics (Cobots) – With the increasing role of cobots in machine tending and related applications, human-machine collaboration in CNC environments will increase, enhancing productivity and safety, particularly in hybrid manufacturing setups.
Conclusion
As seen in the preceding paragraphs, advanced CNC machining offers increased precision, speed, and automation in manufacturing, resulting in complex geometries and high-quality parts. Key benefits include faster production times, reduced labour costs, and consistent accuracy, making it suitable for high-volume and intricate applications. Advanced CNC machining will become a critical pillar of smart manufacturing, enabling flexibility, efficiency, and precision.
However, advanced CNC machining also demands specialised knowledge and skilled operators, and the cost of advanced equipment can be significant. Optimising designs for CNC machining can further reduce costs and lead times. Choosing appropriate materials for CNC machining is crucial for achieving desired results. While offering significant benefits, advanced CNC equipment can be expensive, and a thorough due diligence is called for before investing in these machines, especially on the RoI front. Above all, However, success depends on embracing digital transformation holistically.
Summing up, it is a matter of achieving the right balance depending on the level of precision required for the tasks undertaken. Aerospace, high end automobiles, medical equipment, semiconductor requirements call for ultra high precision and advanced machining. On the other hand there are other requirements where such high precision is not necessary to sustain quality in routine applications. Finally, it also boils down to making manufacturing processes more efficient, precise, and sustainable.
Machine tools are used to shape, cut, or finish parts made of metal or other materials. They are essential for producing a wide range of components, from consumer goods to automobiles, aircraft and spacecraft and parts for other machines. Machine tools form the core part of the manufacturing process of the products in daily use.
Machine tools have evolved over several millennia with records suggesting use of bow drills to make holes in wood and stones by ancient Egyptians, Greeks and Romans in the BC era. These civilisations had also developed the early lathe, operated by two persons, where one person turned the wooden work pieces while the other worked on it with a sharp tool. Such lathes were used to make a variety of objects like containers and furniture parts. Later more advanced tools like water mills and hydraulic presses evolved. All these tools were mostly manually operated, though later horse drawn boring machines were used to fabricate canons. Rapid advances in machining operations were made during the Industrial Revolution that began in the late 18th century with the invention of the steam engine that led to other machines like the spinning jenny and milling machine. These tools, driven much faster by steam power boosted both power and efficiency, and thus began the era of mechanised machine tools.
The development of cast iron beds and slide rests further improved the accuracy and reliability of the machining process, making the lathe truly ‘the mother of all machine tools’. Steam power was later replaced by electric motors by the late 19th and early 20th century as the lathe continued to evolve, improving both speed and precision. From here to semi-automation and further full automation was a relatively short journey, and by mid-20 century, a numerical control (NC) system was introduced with punch cards to control machining operations. The NC system was soon coupled with computers which ushered in the CNC era, with full automation of the operation, raising accuracy to a new high and bringing in complex geometries in parts manufacturing.
Incidentally, this evolution of machine tools happened in tandem with the rapid advancements in the automotive, aerospace, white goods and medical equipment industries. The high precision requirements of these industry segments for intricate parts with complex geometries called for specialised machining capabilities. This in turn pushed the boundaries of innovation in the machine tool industry, spurring mutual advancements in technology, aiding the growth of both segments. To cite just one example, the increased fuel efficiency of modern automobile engines has been largely facilitated by CNC machines that enabled the production of lighter, more efficient, and better-performing components – engine blocks, cylinder heads and differential cases – and vehicle structures. This article explores the current state and future direction of advanced CNC machining.
A visitor checking a latest CNC machine model at TIMTOS exhibition, Taiwan. Image credit: TAITRA.
Current scenario of CNC machining
The contemporary scenario in CNC machining is far removed from the early days, with machines now increasingly automated, digitised, and integrated with smart manufacturing systems. Advanced CNC technologies like 5-axis machining, robotics, AI-driven process optimisation, and digital twins are becoming more common, especially in high-precision industries like aerospace, medical and automotive. However, adoption is uneven, with SMEs lagging due to cost, skill gaps, and integration challenges. The push toward Industry 4.0 and customization is accelerating demand, but widespread adoption still faces notable barriers.
The state of the industry
Necessity is the mother of invention. This well known proverb perhaps has more relevance to the machine tool sector than any other, as all important innovations like numerical control happened as a response to the demands of the industry. The 20th century is known for giant strides made in automobiles, aviation and aerospace, shipping and transport, nuclear energy, the white goods revolution and the medical equipment industry, each having its own set of demands for machining – the art of cutting metal to suit specific requirements. The machine tool industry on its part rose to these challenges admirably, literally providing the cutting edge. Compared to other industries, the digitalisation of the machine tool industry began quite early, in the 1940s with the NC system and progressed further with CNC machines. Further developments like integration of CAD/CAM, PC-based open architecture controllers, use of sophisticated software for advanced machining operations followed.
According to Fortune Business Insights, a leading market research agency that also provides end-to-end solutions beyond flagship research, the global CNC machine tool market size was valued at USD 95.29 billion in 2024. This is projected to grow from USD 101.22 billion in 2025 to USD 195.59 billion by 2032, exhibiting a CAGR of 9.9% during the forecast period. The remarkable market growth is propelled by the healthy demand for more automation and precision in the manufacturing industries. Key sectors driving demand today are automotive, electronics, aerospace & defense, power & energy, construction equipment, and medical devices. The massive infrastructure growth in developing countries as well as growing emphasis on decarbonisation of energy are the leading drivers.
Common CNC machine tools
Apart from the ubiquitous lathe that remains as popular as ever as the most basic machine for any workshop, common CNC machine tools are turning, milling and drilling machines, grinders, plasma and laser cutters, waterjet cutters, electric discharge machines (EDMs), etc. The EDM is not a traditional metal working machine, but a machining process that uses electrical sparks to remove material from a workpiece. Then there are various types of metal forming machines like CNC press brakes, hydraulic bending machines, punch presses and plate rolling machines, also in extensive use. For the record, machine tools today are broadly classified in two groups – metal cutting machines and metal forming machines. Cutting machine tools remove material from a workpiece by shearing or chipping, while forming machine tools reshape the material by bending or pressing, without cutting or removing any of it. Among the leading global manufacturers of advanced CNC machine are well known brands like DMG MORI (Germany & Japan); MAZAK (Japan); MIKRON (Switzerland); MAKINO (Japan); CHIRON (Germany); Okuma (Japan); Hermle (Germany); GROB (Germany); YASDA (Japan); Haas Automation (USA); EMAG (Germany); Doosan (Korea); Matsuura (Japan); Starrag (Switzerland); and Hurco (USA). Apart from these, there are hundreds of other manufacturers. Speaking of countries with large volumes of machine tool production, China, Taiwan, Italy, Spain, and India figure among the leading manufacturers.
Launch of the Mazak Integrex i-630V/6 AG multi-tasking machine at EMO 2023. Image credit: Rainer Jensen/VDW
Multi-axis machines
A significant aspect of modern machine tools is the development of multi-axis machines. Traditionally, CNC machines worked only in three axes – x, y and z – representing linear movements. Together, these movements – left to right (x), front to back (y), and up and down (z) – are enough for most machining applications. However, for parts with complex geometries required for aerospace and medical applications and also in modern automotive components, the 3-axis machines are inadequate and hence multi-axis machines were developed that offered additional rotational axes. Apart from the ability to produce complex shapes, multi-axis machines – 5-axis machines are today commonly used – also provide increased accuracy and faster production speeds with reduced setup times.
Another area where contemporary machine tools have achieved great success is improvement in high precision, high accuracy and repeatability, attributes that matter most in machining parts with sub micron tolerances for demanding applications in aerospace and other industries. This is also aided in no small measure by the integration of CAM software and simulation tools, as well as advanced measuring instruments like Coordinate Measuring Machines (CMMs), laser scanners, and digital micrometers.
Operational improvements
Unattended machining today is no longer a fantasy with robotic loaders, bar feeders, and tool changers allowing 24/7 machine operation. At the moment though there are human supervisors overseeing operations in such automated workshops, lights-out machining is a reality at many manufacturers, the most notable example being FANUC, the company operating its own factory on the lights-out model since 2001. Several other leading machine tool manufacturers are also known to operate their third shift – the most unpopular among human workers – as light-out shift.
The other improvements are IoT-enabled monitoring where sensors capture data like spindle loads, vibrations, and tool wear. Platforms like MTConnect and OPC-UA help standardise data for analytics. With automated inspection, on-machine probing and in-process metrology reduce scrap and ensure dimensional accuracy.
AI generated image of a CNC machine producing a component with intricate design. Image by Freepik
Emerging trends in advanced CNC machining
With advanced CNC machining the following trends are now emerging in the manufacturing space:
Integration of Smart Manufacturing & Industry 4.0
With the advent of Industry 4.0 and the concept of connected machines, CNC machine tools have now progressed into the advanced automation era. Connected machines or Cyber-Physical Machine Tools (CPMT). These machines, equipped with sensors, embedded computers, and network connectivity, integrate computation with physical processes, allowing monitoring, control, and even autonomous operation of CNC machines. Two or more machines now combine to form cells for specific purposes like production of alloy wheels for cars, the machines tended by robots and monitored by AI to oversee seamless integration with automated inspection equipment and image processing technologies. These machines now move effortlessly from mass manufacturing to mass customisation for a hypothetical production run of a single part, one of the basic attributes of the Industry 4.0 ecosystem of smart production.
Predictive Maintenance
One of the significant advantages connected CNC machines bring to the table is enabling predictive maintenance using machine learning by algorithms. The data gathered by sensors of various parameters – temperature, vibration and power consumption – can yield valuable insights on the actual running condition of machines. This is assisted in no small measure by the use of digital twins and simulation. These virtual replicas of physical assets allow real-time monitoring, data analysis, and simulation of various scenarios to predict potential failures and optimise maintenance strategies. This enables proactive maintenance, reduces downtime, and improves asset performance. By addressing issues early, the cost of repairs and component replacements is reduced. Predictive maintenance also ensures machines operate at peak performance for longer periods.
Hybrid Machining – Additive + Subtractive
Perhaps the most interesting trend now emerging in CNC machining is the combination of additive and subtractive technologies into hybrid manufacturing. While traditional machining is subtractive – removing metal from a solid block to get the desired shape, additive manufacturing actually deposits layers of substrates to form a component. The additive + subtractive hybrid machining (ASHM) is ideal to create parts with complex geometries and high precision used in aviation and medical industries. The process overcomes the limitations of each individual method by utilising the advantages of both. For example, a 3D printed part can be subsequently machined to improve surface finish, dimensional accuracy, or to create internal features that are not easily achievable through additive manufacturing alone. More importantly, ASHM can minimise material waste compared to traditional manufacturing techniques. In some cases, it can lead to faster production times by leveraging the rapid prototyping capabilities of additive manufacturing and the precision of subtractive processes.
DMG MORI and Siemens presented the first end-to-end digital twin for machine tool machining on Siemens Xcelerator. Image credit: Siemens
Artificial Intelligence and Machine Learning Applications
Among emerging technologies, Artificial Intelligence and Machine Learning (AI & ML) are the real game changers. Besides helping in predictive maintenance, AI & ML are instrumental in optimising automated toolpaths with real-time parameter adjustments. AI can analyse vast amounts of data to identify patterns and trends, providing data-driven insights for process optimisation. While AI helps automate post-cutting quality inspections to ensure dimensional accuracy and surface finish faster than what is humanly possible, ML algorithms can be trained on historical data to improve the accuracy of CNC machining processes. Besides, AI-powered CNC systems can adapt to new designs and materials with minimal human intervention, making them more flexible and adaptable to changing production needs. AI optimises workflows by analysing data and adjusting machine parameters in real-time, leading to faster production cycles and reduced errors. ML helps by analysing the datasets and then saving for future references, eliminating the need to repeat the process for every cycle, every time. Together, these technologies enhance CNC processes by learning from vast datasets, enabling more dynamic and adaptive workflows, and ultimately reducing waste, production time, and operational costs.
Advanced Materials and Tooling
It is not just technologies that are ushering in revolutionary changes in CNC machining. Advanced materials and tooling are also playing an important role in this revolution by facilitating the production of more complex and precise parts, while also improving efficiency and reducing costs. It is now possible to use high-strength steel and aluminium alloys, and hard-to-machine metals like titanium alloys thanks to a combination of high speed and high precision machining in combination with advanced cutting tools with high performance coatings. Tools made of carbide or ceramic, and coated with various materials like titanium nitride (TiN), titanium carbonitride (TiCN), aluminum titanium nitride (AlTiN), and diamond-like carbon (DLC), are ideal for high speed machining. These tools not only offer superior wear resistance and heat tolerance, but also extended tool life and improved machining efficiency. Besides, the development of new cutting tool geometries and materials allows for faster machining speeds and more complex part geometries. Further, emerging technologies like sensor-equipped tools enable real-time monitoring of tool performance, allowing for predictive maintenance and optimised machining parameters. All these innovations are driving precision, accuracy, and scalability in various industries, including aerospace, automotive, bio-medical and beyond. Also used now are various composites like carbon fibre reinforced polymers (CFRP) which are lightweight, with high strength and durability, making them ideal for aerospace and automotive applications.
Human-Machine Collaboration and Skills Evolution
Amidst the evolution of technology, there is the constant and all important human element for which there is no substitute. Technology is after all produced by human intelligence and efforts, a constant endeavour to make things better. The human-machine collaboration allows for a more integrated approach, where human expertise and machine capabilities are combined to optimise the machining process, ultimately leading to improved productivity and product quality. By leveraging human expertise and machine automation, the collaboration between humans and machines optimises the machining process, leading to increased productivity and higher output. The synergy between human creativity and machine capabilities fosters innovation and problem-solving in the machining process, leading to the development of new techniques and approaches. As humans and machines collaborate, the skills of machine operators evolve to include a deeper understanding of machine capabilities, data analysis, and programming, allowing them to work more effectively with the advanced technology.
Lights out manufacturing for high-mix, low-volume prototyping with robotic automation. Image credit: FANUC
Entry barriers and challenges
With all the advantages highlighted above, advanced CNC machining – technologies like 5-axis machining, multi-tasking machines, automation, and digital twins – ought to be widely adopted globally in quest of better quality and high efficiency of every product manufactured. However, in reality, this is easier said than done. Their widespread adoption faces several entry barriers and challenges despite the potential to revolutionise manufacturing. What exactly are these challenges is briefly examined point by point in the following paragraphs.
1. High Capital Investment – the very first obstacle faced in any new technology adoption globally is the cost, which obviously is high initially. Advanced CNC machines and associated automation (robots, sensors, AI software) are expensive and the return on investment is the first thing that presents itself as a barrier. While large corporations may not face this problem, many small- and medium-sized enterprises (SMEs) that are significant players contributing to manufacturing output, struggle to justify or secure funding for the initial investment.
2. Skills Shortage – A lack of qualified personnel who can program, operate, and maintain advanced CNC systems. This is more so given the penchant of young engineers today to prefer the services industry with better earnings than the manufacturing sector. As a result, the workforce often lacks training in areas like CAD/CAM integration, G-code customisation, 5-axis kinematics, and system diagnostics.
3. Complexity of Technology, Long Learning Curve – Integrating CNC machines with ERP systems, IoT platforms, and AI-driven analytics requires significant expertise and customisation, as well as new workflows and process re-engineering. The main challenges manufacturers face are difficulties with data standardisation, real-time connectivity, and cybersecurity. The inherent tendency of the workforce to resist change adds to the fear of obsolescence.
4. Limited Interoperability and Vendor Lock-In – A serious concern shared by many entrepreneurs is the complexities that arise from having machines from different manufacturers and their proprietary software and interfaces. This limits flexibility and increases long-term costs due to dependence on specific vendors for upgrades and maintenance. Add to that the supply chain and tooling dependencies, and the problem of spare parts that may not be locally available, adding to delays in implementation or increased OPEX.
5. Maintenance and Downtime Risks – Advanced machines have more components and sensors, increasing the risk of technical failures if not properly maintained. This again relates to the lack of adequate skills mentioned earlier. The challenge is the unplanned downtime can be costly and impact production schedules severely.
6. Data management and system integration complexities – CNC machining involves complex interactions between hardware, software, and data systems. Integrating machine data with MES, ERP, or PLM systems is difficult without standardised protocols. Inconsistent formats for toolpath data, machine logs, or maintenance reports create compatibility issues.
7. Regulatory and Compliance Issues – In sectors like aerospace or medical devices, any change in manufacturing technology must be validated and certified. The time and cost of re-certification can deter innovation apart from delaying project execution, adding to costs.
8. Cybersecurity Concerns – The elephant in the connected ecosystem room today is cybersecurity. CNC systems integrated with the cloud or IoT are vulnerable to cyberattacks. The challenge here is to be a step ahead of hackers and cybercriminals. Ensuring secure data transfer, remote monitoring, and protection against malware/ransomware is an ongoing concern.
Future Outlook
Given the rapid pace of evolution of breakthrough technologies, what is the future outlook for the machine tools industry in general, and advanced CNC machining in particular, in the world of manufacturing?
The future of advanced CNC machining not only looks promising, but with its role expanding significantly as part of the broader Industry 4.0 transformation, it is also going to play a significant role in the emerging sustainable manufacturing ecosystem. The following are the key trends shaping this outlook:
1. Cryogenic machining and minimum quantity lubrication (MQL) – Cryogenic machining uses extremely cold liquefied gases, like liquid nitrogen or carbon dioxide, as a coolant during machining to reduce heat and improve tool life. Minimum quantity lubrication (MQL) uses a small amount of lubricant, often atomised and delivered with compressed air, to reduce heat and improve lubrication in the cutting zone. Benefits include increased tool life, especially in hard materials, higher material removal rates. Also uses a minimal amount of lubricant, often delivered as an aerosol with compressed air, to lubricate the cutting tool and workpiece. This approach can improve lubrication and cooling capabilities, potentially leading to better machining performance, especially for difficult-to-cut materials.
2. Greater Automation and Autonomy – Already at the peak of advanced automation, CNC machines will become increasingly self-optimising and autonomous, integrating AI for real-time process adjustments, error correction, and adaptive toolpaths. The age of next generation AI-native, self-learning machines is not too distant now.
3. Full Digital Integration – In line with the emerging industrial metaverse, seamless integration with digital twins, IoT platforms, and smart factory systems will become the norm in the world of CNC machining. This will in turn further fine-tune the already prevailing trends of predictive maintenance, remote monitoring, and simulation-driven machining.
4. Customisation and Agile Manufacturing – CNC machines will play a central role in low-volume, high-mix production to meet the demand for personalised products and rapid design-to-part cycles. The future is in moving beyond mass production to the era of mass customisation.
5. Widespread Use of Advanced Materials – In the quest of energy efficiency and decarbonisation, CNC machines will increasingly handle composites, ceramics, and exotic alloys, driving innovation in aerospace, medical, and automotive sectors.
6. Democratisation via Cloud and AI – Cloud-based CAD/CAM software and AI-assisted programming will lower entry barriers for smaller manufacturers, making high-precision machining more accessible. This will also be supplemented by Machining as a Service (MaaS) – a cloud-based, on-demand manufacturing model where customers outsource their CNC machining needs to a network of service providers, rather than investing in their own machines or facilities.
7. Sustainability and Energy Efficiency – Future CNC systems will focus on energy-efficient operations, minimal waste, and circular economy principles, aligning with green manufacturing goals.
8. Collaborative Robotics (Cobots) – With the increasing role of cobots in machine tending and related applications, human-machine collaboration in CNC environments will increase, enhancing productivity and safety, particularly in hybrid manufacturing setups.
Conclusion
As seen in the preceding paragraphs, advanced CNC machining offers increased precision, speed, and automation in manufacturing, resulting in complex geometries and high-quality parts. Key benefits include faster production times, reduced labour costs, and consistent accuracy, making it suitable for high-volume and intricate applications. Advanced CNC machining will become a critical pillar of smart manufacturing, enabling flexibility, efficiency, and precision.
However, advanced CNC machining also demands specialised knowledge and skilled operators, and the cost of advanced equipment can be significant. Optimising designs for CNC machining can further reduce costs and lead times. Choosing appropriate materials for CNC machining is crucial for achieving desired results. While offering significant benefits, advanced CNC equipment can be expensive, and a thorough due diligence is called for before investing in these machines, especially on the RoI front. Above all, However, success depends on embracing digital transformation holistically.
Summing up, it is a matter of achieving the right balance depending on the level of precision required for the tasks undertaken. Aerospace, high end automobiles, medical equipment, semiconductor requirements call for ultra high precision and advanced machining. On the other hand there are other requirements where such high precision is not necessary to sustain quality in routine applications. Finally, it also boils down to making manufacturing processes more efficient, precise, and sustainable.
