Robotics Redefined

July 17, 2017 12:56 pm

How collaborative robots can help in CNC machine tending.

With the global issue of a qualified workforce becoming harder to find, a robot can be used to execute repetitive tasks and let the worker do value added tasks instead. Unlike traditional industrial robots, which are big, expensive, and work inside safety enclosures, this new generation of collaborative robots is designed to be highly flexible, easily programmable, high quality yet low-cost and safe to operate near people. Machine tending can be repetitive and uneventful.

A collaborative robot can be used to tend machines and relieve employees of repetitive work – freeing their time to be used to add value to your business which in further helps to improve speed and process quality while reducing the risk of injury associated with working in close proximity to machinery. Here’s a look at how collaborative robots help in CNC machine tending:

Cobots can be integrated with semi-automatic machines
According to Kishan Daas GT, Manager-Sales & Applications, DiFACTO Robotics & Automation Pvt Ltd, collaborative robots can be easily integrated with semi-automatic machines, like CNC turning, milling, grinding, drill and tap machines, without the need of much up gradation on the machine. To integrate a robot with these machines, the machines have to be upgraded to an auto door system, addition of safety elements like light curtains, safety fences, pallet systems, etc. and in some cases addition of a PLC for Machine – Robot Communication.

Daas further says, “In the production process there is also a need to do inspection activities like passing the component through a ‘GO – NO GO’ gauge, checking of run-out, dimensional inspection, balancing, etc. and then based on these readings the operator might have to feed in tool compensation data to keep the output within the tolerance. Currently, in many cases, all these are now semi-automatic and operator does this job. All these operations can be automated but the economics would not justify. Considering a standard industrial robot for this application one would have to move the inspection process away from the cell (in many cases this is not feasible) or invest in higher levels of automation to automate these process also.”

Daas informs, “By using a collaborative robot, the operator can perform his tasks along with a robot. The robot could open the machine door by just using one of the gripper fingers and unload and load the job. The operator can continue with the inspection job and carry out the periodic tool offset data entry activities. This way the robot and machine could work together with exchange of a few signals, and this logic can be incorporated in the robot and the Machine CNC and keep the entire system simple and provide good value for money.”

A new concept in automation industry
Pradeep David, Country Head, India & Sri Lanka, Universal Robots says, “Robotic machine tending is a new concept in the automation industry which undertakes loading and/or unloading with parts of material. Machine tending is a dull, potentially dangerous job that requires accuracy and consistency. The person in charge of machine tending must oversee the process. The mundane and repetitive nature of the job makes it an ideal candidate for the application of robotic machine tending for loading, deburring and gauging. A collaborative robot thus, can be used to tend machines and relieve employees of repetitive work – freeing their time to be used to add value to production.”

“CNC machine tending increases efficiency of tasks as varied as sand casting, injection moulding, cutting, machining, and small parts assembly. It can also provide manipulation and transport capabilities that are more complex than basic material handling processes. These robots are used to secure the product from a supply position, transport it to a machine, interact with it and then remove finished parts from the machine. Managing this process by robot minimises incorrect possibility of human error and increases speed and efficiency of production,” claims David.

The basic applications undertaken by machine tending robots are:
• Loading and unloading products for grinding.
• Loading products into CNC milling and turning machines.
• Stamping, punching, trimming, EDM, and forging press loading and unloading.
• Compression mold component materials loading.
• Holding a product for welding operation.
The main advantages of CNC machine tending are as follows:
• Repeatable accuracy and improved quality of production (increases more than 25 per cent).
• Minimises human error and improves ergonomic conditions.
• Short ROI and lower overhead cost compared to manual machine tending.
• Robots can be mounted between two machines or overhead to save valuable floor space.
• Increased machine and system utilisation and capable of 24/7 machine tending.

However, David observes that Machine tending is one of the most monotonous jobs of production process thus making cobots ideal for the same. Their ability to integrate with CNC machines make them a great solution for coordinating with the varied cycle times, supporting finishing operations, and other machine interaction which increases quantity and quality of production along with higher productivity and value added to the company.

Cobots – Safe, reduces complexity and increases productivity
Speaking about how collaborative robots help in CNC machine tending, Sanjay Kulkarni, Managing Director, Pilz India Pvt. Ltd says, “Cobots can help to human operators relieve of repetitive work freeing their time to add value to the business. It also helps in replacing human operators in dirty and dangerous machines avoiding accidental injuries.”

However, he observes, there are many parameters and specifications of robots, gripper and required workspace that we need to decide before one can choose a robot that can accomplish the job and reaches a level of performance comparable to a human worker. He adds, “Some of the specifications to consider for the collaborative robots are payload i.e. the total weight of the part it’s going to carry, repeatability i.e. the robot should put the product at the very same spot every time it operates, and reach.”

Other than this gripper specifications like stroke and payload are to be considered. “The use of collaborative robots will definitely going to increase in near future as it is safe, reduces the complexity and increases productivity,” says Kulkarni.

Programming a robot is easy, doesn’t require special training
According to Anurag Vishwakarma, Proprietor, Modern Automation & Robotic Systems (MARS), “With the changing technology, the man machine interface has narrowed down drastically. The increased use of CNC machines in high volume quality components, collaborative robots can ease out the manufacturing complexities. Machine can completely replace the man required to run the machine. In a highly advanced machine shop where the manufacturing is done on CNC machines, robots can be installed to work in collaboration with the machines. When the robot density is high in either CNC machine operation or in assembly lines, a central control system can monitor all the robots working in work cell.”
He adds, “The robots are now easy to program and it does not require any special training. The smart robots can be programmed by teaching the movement path simply moving the robot arm manually in teach mode. The operations can be either opening the machine door, loading the part or placing the part in correct location. The movement path is retained in the memory and can be called as the part changed. Complex movements can be executed with the new generation robots.”

Vishwakarma also feels that Indian industry is still lagging behind in using automation and robotic systems in their workplace. The reason being the cost and the lack of skill level. Most of the work is still done manually by hand. Processes like polishing and buffing generated dust and dirt and involve complex movements, highly skilled operators are needed to execute this operation. Robots can be used to eliminate the skill and unhealthy work environment. The work can be done in a closed compartment keeping the shopfloor clean.

“The next generation has entered in the industry and implementing new thoughts and robots to ease out the process. The advanced technology will change the way the machine shop works in very short time and robots will take over the operators very soon,” explains Vishwakarma.

Adaptability: The new competitive advantage
Nitin Wakode, Associate Vice President PSG, Onward Technologies Ltd says, “Machine tending is not a new trend but we need to understand the adaptability to Indian conditions. We all know machine tending is one of the most tedious boring task being repetitive in nature. India is country with ample availability of low cost manpower. The factor which a European or American usually put to justify use of robot is to reduce manpower cost is not valid in India and low cost countries like China, Taiwan, Philippines, Brazil and few other Asian countries. But Indian industry has realised the importance of robotic implementation and adaptability challenges. Indian industry is looking for right mix of automation and human resource. It is obvious we can’t ask human to compete with such high performing CNC machines. In order to balance the line or to match the speed of part cycle time and turnaround time of machine we must consider automation. Robot tending is one of the parts of the system but it will have to be complemented with automated conveyors, automated storage and retrieval systems.”

According to Wakode, there are many other reasons which are making us to think and act on it which include:
• Due to the latest machine tool technology cycle times are too short hence human can reach fatigue level easily in very short time.
• When the fatigue levels are high you tend to find effect on productivity and quality as well.
• Operational hazard, due to high speed machining most of the times chips are red hot with sparks.
• Small batches with automated process flow can be effectively achieved using robotic arm.
• Too small parts or too heavy parts calls for robotic arm tending.

Wakode informs, “Factories are in mode to adopt new technology in order to remain with the global market trend. Industry 4.0 revolution is considered to be on priority agenda for all the industries. Here, we expect every equipment to provide real-time data to make sure the plans are met and if there is any contingency the plan 2 is executed based on the logic incorporated. Machine tending will ensure very close and predictable production schedules. Ideally, Industry 4.0 needs complete automation of the process.”

However, he adds, “We know that many of our links are still manual. With the implementation of Industry 4.0 we can see great scope for machine tending and automation. Some of the modern Indian factory shopfloors are almost man-less where many of the machines are integrated with robotic automation, some robots are also integrated with other robot to work in collaboration and synchronisation. It is for sure with time machine tending going to be integral part of new generation machines.”

Helps to execute repetitive tasks
Commenting on how collaborative robots help in CNC machine tending, Vikas Taneja, Vice President – Marketing, Jyoti CNC Automation Ltd says, “With the global issue of a qualified workforce becoming harder to find, a robot can be used to execute repetitive tasks and let the worker do value added tasks instead. Unlike traditional industrial robots, which are big, expensive, and work inside safety enclosures, this new generation of collaborative robots is designed to be highly flexible, easily programmable, high quality yet low-cost and safe to operate near people. Machine tending can be repetitive and uneventful.”

He adds, “A collaborative robot can be used to tend machines and relieve employees of repetitive work – freeing their time to be used to add value to your business. These robots improve speed and process quality while reducing the risk of injury associated with working in close proximity to machinery.”

‘Humans’ and ‘robots’ together on the factory floor
According to P.G. Jadeja, President, IMTMA, Collaborative robots (Cobots) is human-robot collaboration which drives the industry and has major benefits including:
• Humans and robots working together as a team can be around 85 per cent more productive than teams made of either human beings or machines alone.
• Single phase power supply like a hand tool with a maximum power consumption of 350 W.
• Easy to program and fast set up in less than an hour.
• Operates in confined spaces; (±) 360-degree rotation on all axes.
• Flexible redeployment.
• Cobots are advanced tools used by production staff to enable them do their tasks better.
• Manufacturing system is being redesigned to ensure that human – robot collaboration is possible to ensure that productivity, quality and safety are maximised.
• Many call it the 5th industrial revolution as companies are using this technology to cater to low volume customised runs and re-shore their lost jobs while moving manufacturing nearer to where the consumer is.