Making the Cut

Machine Tools/CNC

No more are cnc machines just plain vanilla. makers are offering and customising for clients based on their needs.

By Team MT

In the last few years, affordable CNC machines have entered almost every machine shop, and have dramatically increased the quality, and lowered the cost of parts. Today, CNC machines have become an integral part of manufacturing. Rising prices of capital goods is compelling manufacturers to machine more and more components, that cannot be outsourced, in-house. CNC machine manufacturers, on their part, too are launching high-end machines to meet the demands of customers.

Last month, Galaxy TajMac India, a joint venture between Galaxy Machinery India and Czech-based TajMac-ZPS, launched the first ‘Made in India’ CNC machines. The CNC sliding headstock lathes in 6–12 axes will be made at the company’s facility at Udyambag, in Belgaum, Karnataka. It has its own component processing facility for in-house manufacturing of all critical sub-assemblies and precision components. Elango S, director, Galaxy-TajMac India, said that this will give the company an edge in terms of pricing and enable them to price the machines 20% less than those available in the market.

With increasing demand for new types of work these machines are being paired with automation systems and simulation software to increase production. Arun Nene, manager, channel support, Jyoti CNC Automation, says, “With the increase in demand of production efficiency, the CNC machine market is set to grow. Interestingly, with the pairing of automation, it offers reduced human dependency. Advance programming increases productivity. Automation leads to simplification of production and reduces intensity of labour. Lately, companies have begun integrating robots with CNC machines.”

Come to see, across large manufacturing shopfloors, it is a common sight to see robotic arms, gantry, auto loaders and material handling systems incorporated with CNC machines for improvement in productivity. Necessarily in the production of prototype parts, it is automated cuts that improve speed and accuracy. “Programmed parameters are set to inspect wearing of cutting tools. The convergence between the machine tool control and the Internet of Things (IoT) is at the forefront,” adds Nene.

The latest buzz in modern manufacturing fraternity is Industry 4.0. In terms of CNC machines, the advancements in production make machine manufacturers offer great flexibility and enables users to make faster decisions. Amit Jain, DGM, production, Barco Electronic Systems, says, “CNC machines are benefitting from automation. Considering that we make display machines, accuracy is most important. The machines we use are high on computing power and proportionally increase the productivity or quality of machined parts.”

Shankar Muguru Srikantiah, sr VP, technology & innovation, Anand Automotive, says, “There are new kinds of software that enables one to run several machines. Benefits include support for most machine controllers (the basic substance of a CNC system that reads coded instructions, decodes them and implements circular, helical and linear interpolations to create axis motion commands) and the ability to write custom scripts to help skip steps (depending on the job, machine shop, etc.) and create advanced nesting features (nesting is the process of laying out cutting patterns to minimise subtracted material waste).”

Although there are several benefits of CNC and automation, there are still barriers to overcome. The primary assumption of many is that CNC machines can be left unattended once they have been automated; running all night and weekend in the dark. This is untrue. CNC machines can be set up to run finishing cuts and operations at night by only if done properly by the operator. They must inspect the cutting tool is not worn out and that the programmed parameters are set. The CNC machine will not detect wear on a tool bit. The thermal expansion of the machine is another parameter that must be carefully monitored. While thermal expansion algorithms can help predict when a tool is out of tolerance, operators still need to adjust warning indicators and perform measurements on the tool after machining processes are complete; changing the tool if necessary. Nene says, “To leave operations unattended and to run finishing cuts, the CNC machine must be equipped with raw stock input, high pressure coolant, part gauging techniques, redundant and full time tool monitoring. To meet the demands of Industry 4.0, we have developed TMC (Total Machine Competency) software called 7th Sense. This TMC software would take care for productivity as well as efficiency of the machine.”

The global CNC market is poised to grow at a CAGR of around 7.2% over the next decade to reach approximately $5.42 billion by 2025. Some of the prominent trends that the market is witnessing include efficient and effective motion control system solutions, high maintenance and implementation costs, high speed and accuracy, growing infrastructural developments and technological innovations in the market and increase in foreign investments in the market growth.

There’s also a general trend among manufacturers to ‘condition monitor’ their CNC machines. Mostly, this involves putting sensors in their machines. The growth of sensors is not in isolation. While the sensors are getting cheaper and more powerful, they would be useless if there was not a way to use that data in a coherent manner. Sensors and condition monitoring is not new, of course. Operators of machinery have been keenly aware that a few fundamental measurements can help them keep critical assets running smoothly. Ravindra Dayal, executive director (Gujarat project), Maruti Suzuki India, says, “Though it takes us over 8 hours to make one car, but considering the number of cars we make per month, we can safely say that it takes us 12 seconds to make a car. In such a scenario, it is important that we machine certain critical components within the plant. So cylinder heads and blocks, transmission case, valves are made within the plant.”

Speaking about machining awithin the plant, Ganesh Mani, sr. VP, production, Hyundai Motor India, says, “We use 5-axis CNC milling machines to create a life-size model of cars which is then completed under the expertise of modellers. Moreover, we also make several components in-house so that we can offer customers benefits of pricing.”

Customer benefits are a prime concern for CNC machine makers. The thermal expansion of the machine is another important parameter that must be carefully monitored for achieving better accuracy of job. While thermal expansion algorithms can help predict the impact and need to compensate, with tool monitoring system, the geometry of tools is studied and relative compensation helps enhance tool life and job accuracy. These will help maintain the production performance. Today, the productivity needed to be globally competitive requires ever increasing metal-removal rates during operations such as roughing and high-speed slotting. Process reliability is paramount, especially when working with difficult-to-machine materials. Conventional toolholders typically do not cope well with the high axial forces generated by aggressive machining, and cutter pullout can occur.

In fact, clients are opening up to investing in high-technology, and are conscious about total cost of ownership, which was unheard of earlier. “When we invest in a high-end machine, we would like to know the end-to-end value for money, the kind of change over time, the kind of tools needed, and speed of the spindle. So, there is a shift in mindset when buying high-end machines,” says Mani.

For many years, machining was a largely manual process with relatively slow speeds and shallow cutting depths. Under these comparatively benign machining conditions, cutting tool slippage or pullout was not a serious issue. Today, the productivity needed to be globally competitive requires ever increasing metal-removal rates during operations such as roughing and high-speed slotting. Process reliability is paramount, especially when working with difficult-to-machine materials. Conventional toolholders typically do not cope well with the high axial forces generated by aggressive machining, and cutter pullout can occur. Manufacturers have responded with a variety of rigid, highly secure systems offering anti-pullout protection. These include shrink-fit, hydraulic expansion and locking toolholders. Each features high gripping torque (clamping force) for a tight friction fit on the tool shank.

Farrokh Cooper, CMD, Cooper Corporation, says that this is seeing a positive change. “We have noticed a significant change among vendors who are putting in a conscious effort to work closely with the manufacturing companies. There’s also an initiative to understand our needs and offer customised solutions. Many vendors are offering flexibility in terms of modifying their machines, according to the change in product specifications and providing comprehensive solutions,” he adds.
On the whole, this high-technology industry is poised to see a growth if more manufacturing companies.


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May 2019
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