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CNC Machining with Robotics

CNC Machining with robotics Advances in the intelligence of robotics have us thinking of futuristic Sci-Fi movies but robots have been used in CNC machining and manufacturing since the late 1960s. Automotive manufacturers, for example, have used robots on their assembly lines handling heavy materials and speeding up onerous tasks such as welding and fastening bolts in difficult spaces. The addition of artificial intelligence now allows robots to function in harsh environments where vision or other sensing is needed, like sorting recycling. Robots performing repetitive tasks with precision and speed are perfectly suited for CNC machining.

Basic Robotics

Robots generally replicate the movement of an arm; some more complicated and fluid and some more static with a single linear movement. Each will have a motor, electronic controllers and sensors to receive programming and monitor movement, as well as the mechanics of the arm and base. Robotic arms fall into three main categories:

Articulated Arm – A single arm that moves on multiple planes at multiple joints, seemingly even more complex than the human arm. A more simplified version is the SCARA Arm (Selective Compliance Articulated Robot Arm) which moves on two parallel planes only.

Delta Robots – Typically with joints only at the base, this type of robot can move at a very high speed due to the simplicity of the single linear movement.

Gantry Robots – Gantry systems have been used in CNC machining from the introduction. This robotic system moves in linear planes, typically the X, Y, and Z axes, making a cube shape in its movements. The term gantry table in machining reflects this concept.

Advantages

Productivity – As good as an employee may be, they still require breaks and vacation, they are susceptible to illness or injury, and they tire of repetitive tasks sometimes resulting in error. Robotics makes continuous manufacturing possible. They handle changeover easily and sensors regulate quality during processing. Since each piece of robotics is designed and calibrated to work on particular tasks, they seamlessly add to the functionality of the CNC machine.

Accuracy – Just as CNC machining reduces the human error component of machining, robotics increases that capability even more with loading, holding, and, even, packaging parts. The importance of people in the manufacturing process is moved to design, machine supervision, and maintenance, utilizing their skills more appropriately than for repetitive or dangerous tasks.

Flexibility – The End Effector of a robotic arm is like the Swiss army knife of the assembly. A robotic arm in CNC machining can have different “hands” connected to suit the programming. The function can range from grasping with a pincer or suction-cup action to blowing compressed air. One robot can serve multiple machines and applications by reprogramming and adding a new device at the wrist of the arm.

Ease – A new program will work on the first try as opposed to the human learning curve where it may take longer or produce errors until it is understood. In addition, a robotic arm may load multiple machines under one program to further improve productivity with one robot.

Safety – Robotics can eliminate accuracy and training times for machine shop personnel but act just as effectively to protect people from high temperatures, chemicals, or injury from improper machine use. CNC machines work with high force and high speeds that present constant danger for machine-shop staff.

Cost

With all these advantages you may wonder why every machine shop doesn’t employ robotic attachments to all their CNC machines. Capital investment can be perceived as high but, on closer look, the flexibility and cost savings on labour are well-worth the investment. Initial setup is best guided by experts and maintenance improves robot performance and lifespan.

Turning the Tables

Using CNC machining to build robots provides the same benefits as utilizing them in CNC machining. Due to their manufacturing environment, robotics are often made with parts from strong materials like steel, aluminum, and some plastics, all perfect candidates to be made from a CNC machining process.

Consider a robotic arm, bending and flexing like a human arm. Parts must align exactly like the relationship of cartilage and bone making dimensional accuracy and smooth parts finish compulsory. Moving that arm over hundreds and thousands of repetitions in its lifetime, quality components reduce friction and wear.

Producing multiple robots for assembly work or individual applications both lend themselves to the speed and accuracy of part creation through the repeated or custom processing available with CNC machining.

This brings CNC machining with robotics full circle. We can produce the parts that make the robots to, then, further improve part manufacturing. Large assembly-line production is no longer the main application for robots. Smaller manufacturers use robots coupled with artificial intelligence to truly remove man from the dangerous and repetitive tasks of CNC machining. As AI and other technologies continue to improve, the applications of robotics will continue to expand.

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