Over the last two decades, the use of automated machining and CNC robotics has grown incredibly. For industrial automation, the manufacturers are recognizing both Robotics and CNC machining as top-notch solutions. There is an overlap between CNC machining and Robotic machining and the lines between them are often diminishing. Robotic CNC machining is a cost-effective process that will minimize the use of a larger workforce. The only requirement for robotic CNC machining is effective servicing at regular intervals. CNC machining plays a vital role in producing robotic parts and it will also benefit from the implementation of robotics.
CNC robotic arm
What is CNC Robotics?
An industrial robot generally consists of a single manipulator arm, which is attached to the base. Majority of the industrial robots have 3 to 6 axes, which will determine the range and motion of the robot. The end-effector is the device, which is used to interact with the workpiece and it is attached to the end of the robot arm. Generally, articulated robots are programmed by using a teach pendant or computer software. These robots are widely used in most manufacturing processes such as robotic assembly, welding, material handling, material removal, robotic machining, and robot palletizing.
CNC robotics is referred to as the additional process, which will assist the Computer Numerical Control (CNC) machining. The CNC robot is an industrial robot, which is designed and developed exclusively for machining applications. It will handle different processes on its own by following the programmed engagements and it does not require any input from an operator. CNC robotics will enhance the advantages of automation in manufacturing processes by ensuring mass production with high accuracy, precision, and tight tolerances in the medical, automotive, and robotic sectors. The implementation of robotics will not only benefit CNC machines but the robotic parts can also be manufactured through CNC machining.
Applications of CNC machining in Robotics
1. Robot Arm
The majority of the robot arm designs are similar to the human arm. For the same, some of the robot arm parts are named after the human parts such as shoulder, elbow, and wrist joints. Initially, the robot arm is used for the automated die-casting process, and later on, it is used for different applications such as CNC machines, material handling, and lift and drop objects. In order to lift heavy weights and apply force, the robot arm should be strong and stiff with high-strength materials such as Steel, aluminum and plastics. CNC machining would be the ideal process, as it can produce parts with different materials as per the requirements. Besides that, without degrading the part’s structural integrity, CNC machining can produce plastic components with a subtractive nature.
2. End Effectors
The end effector is a necessary device that is attached to the end of the robotic arm. This device will help the robot to interact with multiple objects and to perform various tasks. It has various designs and functions such as grippers, grabbers, suction pumps, and vacuums . Depending on the functional requirements, the end effectors should have different roughness values. The manufacturers are choosing CNC machining to produce the end effectors with different designs and roughness values.
3. Modular Tooling
The modular tooling is assembled with a set of common building blocks, adapting to a common machined connection on the end of the robotic arm. With this, the robotic arm can quickly and easily change the tooling from a gripper to a suction pump and vacuum. The modular tooling is similar to the CNC machines with the tool changers employ. CNC machining is the optimal choice with the highest quality and precision to fabricate the indigenously designed modular tooling.
4. Custom Jigs and Fixtures
The majority of the robotic operations are accomplished by using customized jigs and fixtures. While the robots work on products, they will assist the robots by holding the workpiece in place. As these jigs and fixtures are customized according to the requirements, to fabricate them, the manufacturers are selecting CNC machining as it is a cost-effective machining process.
5. Sensors and Controllers
Printed Circuit boards
The majority of automation devices and robots have sensors and controllers with Printed Circuit boards (PCBs) as their essential components. Earlier PCBs are manufactured by using a chemical process known as chemical etching. This chemical etching process uses a harmful substance known as ferritic chloride, which causes skin irritation to humans and it requires an extensive waste disposal process. The manufacturers are using CNC machining as an alternative to chemical itching, which will fabricate the PCBs with high accuracy and precision.
The robots can not move their arms and joints without using any motors. The motors will consist of both electrical and mechanical devices. These motors must have a machined enclosure and bracket to attach to the robot arm’s power source according to the design requirements. Any mistake during the manufacturing of this enclosure and bracket will lead to the interruption of the robot’s arm movement during the operation. The manufacturers are preferring CNC machining to produce these enclosures and brackets with high accuracy and tight tolerances.
Advantages of CNC machining in Robotics
1. Increased Speed
CNC machining requires very short lead times to produce the robotic components and it is a rapid process compared to other manufacturing processes. With this, the manufacturers can produce customized robotic parts with various iterations for different applications. CNC machining can produce robotic parts within days as per their complexity and size.
2. Dimensional Accuracy
For high-performance robots, high precision and dimensional accuracy are the primary requirements. CNC machining can produce numerous robotic parts with high precision, dimensional accuracy and tight tolerances of ± 0.001̋.
3. Material Compatibility
The main objectives of a robotic arm are to move steadily and lift and transfer objects. For this, it requires different materials of metals and plastics with a good strength-to-weight ratio. CNC machining is the ideal process to produce parts with a wide range of materials from metals and plastics. With this, the manufacturers are completely dependent on CNC machining to produce robotic parts.
4. Surface Finish
The robotic end parts which are interacting during the manufacturing process must have low friction. The CNC machining can produce parts with a surface roughness of Ra 0.8 µm or lower. In order to improve their functionality, these parts can also go through additional surface finishing operations.
Will Robots replace CNC Machines?
CNC machines and Robots
The core functions of the CNC machines and Robots are slightly different. For both, the input is given in the form of a programmed code, but the fundamental differences are based on the complexity and variation of that particular task. In order to manufacture a specific type of product with a good surface finish, the CNC machine is extremely used. On the other hand, robots are flexible and easily adapted to perform different operations.
Although the robots are highly approved, they will never fully replace the CNC machines due to its less robust. Robotic machining can be seen as a viable alternative depending on the complexity of the final product and the surface finish required. Majorly, the robots are utilized to perform pick and drop operations, moving parts from one machine to another machine without any human intervention and being able to use as additional 5th and 6th axes for CNC machines.
Common Robots used in CNC Machining
1. Articulated Robots
In general, the majority of industries are using articulated robots. They have rotary joints commonly known as axes and these axes will offer an additional degree of freedom to ensure independent motions. The simple articulated robots will have two-axis structures and complex structures will have more than 10 axes. The articulated robots are ideal for handling various workpieces in different sizes due to their enhanced range of motion and flexibility. The typical applications of these robots include Arc welding, Material handling, packaging, Assembly and Machine loading operations.
2. SCARA Robots
Selective Compliance Articulated Robot Arm (SCARA) is a four-axis robot designed to handle high-speed and repetitive operations . These robots can also handle low payloads with high speed and precision. By ensuring the safety of the workforce, these robots’ swiftness and effectiveness can achieve higher productivity rates along with cost-efficiency. The typical applications of these robots include Assembly operations, Machining, Packing, Inspection, and pick and drop operations.
3. Delta Robots
These robots are used for high-speed applications in the manufacturing industries and are commonly known as parallel-type industrial robots. As the name suggests, the delta robot consists of an upside-down triangular shoe and these are generally mounted on top work areas, which are usually conveyors that move the parts down to the production line. With this unique design and configuration, these robots will have notable advantages compared to others. The typical applications of these robots include Assembly, Disassembly, Packing, Sorting, Pick and drop operations.
4. Cartesian or Gantry Robots
The name indicates that these linear industrial robots work on three axes using the X, Y and Z cartesian coordinate system. Due to their higher flexibility, these robots are widely used. The robot’s precision, size, speed and stroke length can also be easily adjustable. These robots are suitable for working with high-range and payload workpieces. The typical applications of these robots include Assembly, Loading and unloading, Material handling, Pick and drop, Fastening and Screw driving, and Packing and Cutting (Laser and Waterjet) operations.
There are a huge growth in the use of automated machining and CNC robotics over the last two decades, CNC machining plays a significant role in this field. Are you looking to machine your project? Prolean is one of the quality manufacturing companies in China, we commit to pro-service and lean manufacturing. Check our CNC machining service and get your quote today.
1. What are the Materials used for robotic parts?
Firstly, the parts for robotic applications have the requirement to be strong, tough and lightweight. Depending upon the application different classes of materials can be used.
Metals: Steel, Aluminium, copper, brass, bronze and Titanium.
Plastics: Polystyrene, Plexiglass, Rigid PVC, ABS Plastic, PETE and Nylon
Composites: Fiberglass and Carbon fiber.
2. How robots can aid CNC machining?
Generally speaking, the programmed code can help to ensure that the industrial robot will operate efficiently, and safely and can also aid in completing automated operations. For example, hand-finishing tasks can be completed by CNC robotic systems. The polishing operations can be efficiently performed by using industrial robots with variants of 5-axis milling capabilities. Other than this, the robots can now complete tasks such as loading raw material into the machine, controlling the process, unloading the finished products and controlling product quality with automated quality inspection.