Computer numerical control: How to Control and Operate Machines with Computers

1. What is computer numerical control (CNC) and why is it important?

Computer numerical control (CNC) is a process of controlling and operating machines with computers. CNC machines are devices that can perform various tasks such as cutting, drilling, milling, turning, and more, by following a set of instructions or codes that are programmed into them. CNC machines are widely used in various industries such as manufacturing, engineering, aerospace, medicine, and more, because they offer many advantages over conventional machines. Some of these advantages are:

1. Precision and accuracy: CNC machines can produce high-quality products that meet the exact specifications and dimensions required by the design. CNC machines can also repeat the same process with consistent results, which reduces the chances of errors and defects.

2. Efficiency and productivity: CNC machines can operate faster and longer than human operators, which increases the output and reduces the waste of time and materials. CNC machines can also perform complex and intricate tasks that are difficult or impossible for human operators to do manually.

3. Flexibility and versatility: CNC machines can be easily reprogrammed and adapted to different tasks and materials, which allows them to handle a variety of products and designs. CNC machines can also switch between different tools and functions automatically, which eliminates the need for manual adjustments and setups.

4. Safety and security: CNC machines can reduce the risk of injuries and accidents for human operators, as they can work in hazardous or dangerous environments that are not suitable for humans. CNC machines can also protect the intellectual property and confidential information of the products and designs, as they can be encrypted and secured from unauthorized access.

As you can see, CNC is an important and useful process that can control and operate machines with computers. CNC can improve the quality, efficiency, flexibility, and safety of the products and processes, and can also enable new and innovative possibilities for various industries and applications. In the next sections of this blog, we will explore more about how CNC works, what are the components and types of CNC machines, and how to program and use CNC machines. Stay tuned!

2. How did CNC evolve from manual to automated machining?

The history of CNC is a fascinating story of how humans have developed tools and technologies to shape and manipulate materials with precision and efficiency. CNC stands for computer numerical control, which means that a computer program controls the movement and operation of a machine tool, such as a lathe, a mill, or a router. CNC machines can perform complex and intricate tasks that would be impossible or very difficult to do manually. CNC machines have revolutionized the fields of manufacturing, engineering, design, and art, among others. In this section, we will explore how CNC evolved from manual to automated machining, and how it has changed the way we create and produce things. We will look at the following aspects of CNC history:

1. The origins of machining and the development of manual machine tools. Machining is the process of removing material from a workpiece to create a desired shape or surface. The earliest forms of machining date back to ancient times, when humans used simple tools like chisels, hammers, and files to shape wood, stone, metal, and other materials. As civilization progressed, more advanced tools and techniques were invented, such as lathes, drills, saws, and planes. These tools were operated by hand or by mechanical power sources, such as water wheels, steam engines, or electric motors. Manual machine tools required a high level of skill and experience from the operator, who had to adjust the speed, feed, depth, and direction of the cutting tool manually. Manual machine tools were also limited by their accuracy, repeatability, and complexity, as they could only perform simple and linear motions.

2. The emergence of numerical control and the first CNC machines. Numerical control (NC) is the precursor of CNC, and it refers to the use of coded instructions to control the movement and operation of a machine tool. The idea of numerical control was first proposed by John T. Parsons, an American engineer and inventor, in the 1940s. Parsons was working on a project to produce more accurate and complex helicopter rotor blades for the US Air Force. He realized that the conventional methods of machining were too slow and inaccurate, and he devised a way to use punched cards to store the coordinates of the blade profiles. He then used an IBM computer to calculate the optimal cutting paths and feed them to a modified milling machine. This was the first example of numerical control, and it paved the way for the development of the first CNC machines in the 1950s and 1960s. CNC machines used electronic and digital systems to store and execute the coded instructions, and they could perform more complex and non-linear motions than NC machines. CNC machines also had feedback mechanisms, such as sensors and encoders, to monitor and correct the position and speed of the cutting tool. CNC machines offered many advantages over manual and NC machines, such as higher accuracy, repeatability, productivity, flexibility, and safety.

3. The evolution and innovation of CNC technology and applications. CNC technology has evolved and improved over the years, thanks to the advances in computer hardware, software, and communication. Modern CNC machines use microprocessors, memory chips, and graphical user interfaces to store and display the program instructions, and they can communicate with other devices and networks via wireless or wired connections. CNC software has also become more sophisticated and user-friendly, allowing users to design, simulate, and optimize the machining process using computer-aided design (CAD) and computer-aided manufacturing (CAM) tools. CNC applications have also expanded and diversified, as CNC machines can now handle a wide range of materials, such as metals, plastics, ceramics, wood, and composites, and perform a variety of operations, such as turning, milling, drilling, cutting, engraving, and 3D printing. CNC machines have also enabled the creation of new and innovative products and artworks, such as sculptures, musical instruments, jewelry, and furniture, that showcase the creativity and versatility of CNC technology.

3. What are the different kinds of CNC machines and what can they do?

CNC machines are devices that use computer numerical control (CNC) to automate various machining processes, such as cutting, drilling, milling, turning, and more. CNC machines can produce precise and complex shapes from different materials, such as metal, wood, plastic, and composite. CNC machines can vary in size, design, and functionality, depending on the type of operation they perform. There are many different kinds of CNC machines, each with its own advantages and disadvantages. In this section, we will explore some of the most common types of CNC machines and what they can do.

Some of the most common types of CNC machines are:

1. CNC lathe: A CNC lathe is a machine that rotates a workpiece along a fixed axis and uses various cutting tools to remove material and create cylindrical shapes. A CNC lathe can perform operations such as facing, turning, boring, threading, and grooving. A CNC lathe can produce parts such as screws, bolts, shafts, rods, and pipes. An example of a CNC lathe is the Haas ST-10.

2. CNC mill: A CNC mill is a machine that uses a rotating cutting tool to remove material from a stationary workpiece and create various shapes and features. A CNC mill can perform operations such as drilling, tapping, contouring, pocketing, and slotting. A CNC mill can produce parts such as gears, molds, dies, and brackets. An example of a CNC mill is the Tormach PCNC 1100.

3. CNC router: A CNC router is a machine that uses a spinning cutting tool to cut out shapes from a flat sheet of material, such as wood, plastic, or aluminum. A CNC router can perform operations such as carving, engraving, cutting, and trimming. A CNC router can produce parts such as signs, furniture, cabinets, and musical instruments. An example of a CNC router is the Shapeoko 3.

4. CNC plasma cutter: A CNC plasma cutter is a machine that uses a plasma torch to cut through electrically conductive materials, such as steel, copper, and brass. A CNC plasma cutter can perform operations such as cutting, piercing, beveling, and gouging. A CNC plasma cutter can produce parts such as metal art, sculptures, and frames. An example of a CNC plasma cutter is the Hypertherm Powermax 45.

5. CNC laser cutter: A CNC laser cutter is a machine that uses a focused beam of light to cut or engrave materials, such as wood, acrylic, leather, and paper. A CNC laser cutter can perform operations such as cutting, engraving, etching, and marking. A CNC laser cutter can produce parts such as logos, labels, stamps, and jewelry. An example of a CNC laser cutter is the Glowforge Plus.

These are just some of the types of CNC machines that are available in the market. There are also other types of CNC machines, such as CNC EDM, CNC waterjet, CNC press brake, and CNC 3D printer, that can perform different kinds of operations and produce different kinds of parts. CNC machines are versatile and powerful tools that can help you create amazing products with high accuracy and efficiency.

4. What are the main parts of a CNC machine and how do they work together?

CNC machines are devices that use computer numerical control (CNC) to automate the movement and operation of various tools and parts. CNC machines can perform tasks such as cutting, drilling, milling, turning, and more with high precision and accuracy. CNC machines consist of several main components that work together to execute the instructions from the CNC program. These components are:

1. The controller: The controller is the brain of the CNC machine. It receives the CNC program from the computer and converts it into electrical signals that control the movement and operation of the other components. The controller also monitors the feedback from the sensors and adjusts the signals accordingly to ensure the accuracy and quality of the output.

2. The spindle: The spindle is the part of the CNC machine that holds and rotates the cutting tool. The spindle can have different speeds and power depending on the type and size of the tool and the material being processed. The spindle is driven by a motor and can be controlled by the controller to change its speed and direction.

3. The tool changer: The tool changer is the part of the CNC machine that allows the spindle to switch between different cutting tools automatically. The tool changer can have different configurations and capacities depending on the number and type of tools required for the CNC program. The tool changer is also controlled by the controller and can be activated by the CNC program to change the tool at the appropriate time and position.

4. The table: The table is the part of the CNC machine that supports and holds the workpiece. The table can have different shapes and sizes depending on the type and size of the workpiece and the CNC program. The table can also have different features and attachments such as clamps, vises, fixtures, and more to secure and position the workpiece properly.

5. The axes: The axes are the part of the CNC machine that allow the spindle and the table to move in different directions and angles. The axes can have different numbers and configurations depending on the type and complexity of the CNC program. The axes are usually labeled as X, Y, and Z for the linear movements and A, B, and C for the rotational movements. The axes are also driven by motors and controlled by the controller to move according to the CNC program.

6. The sensors: The sensors are the part of the CNC machine that provide feedback and information to the controller and the operator. The sensors can measure different parameters such as the position, speed, temperature, pressure, and more of the components and the workpiece. The sensors can also detect errors and faults in the CNC machine and alert the controller and the operator accordingly.

These are the main components of a CNC machine and how they work together to perform the CNC program. By understanding the functions and roles of these components, you can better appreciate the capabilities and advantages of CNC machines. CNC machines can offer benefits such as increased productivity, efficiency, accuracy, quality, and flexibility in manufacturing and engineering. CNC machines can also create complex and intricate shapes and designs that are difficult or impossible to achieve with manual or conventional machines. CNC machines are widely used in various industries and applications such as aerospace, automotive, medical, construction, and more. CNC machines are constantly evolving and improving with the advancement of technology and innovation. CNC machines are one of the most important and influential inventions in the history of human civilization.

5. How to create and edit CNC programs using codes, commands, and software?

CNC programming is the process of creating and editing instructions for a computer-controlled machine to perform a specific task. CNC programs are written in a special language called G-code, which consists of codes and commands that tell the machine how to move, where to position, what speed to use, what tool to select, and other parameters. CNC programs can also be created and modified using software applications that allow the user to design the desired shape or pattern on a graphical interface and then generate the corresponding G-code automatically. In this section, we will explore how to create and edit CNC programs using both methods: codes and commands, and software.

### Codes and Commands

To create a CNC program using codes and commands, you need to have a basic understanding of the G-code syntax and structure. G-code is composed of blocks, each of which contains one or more words. A word consists of a letter followed by a number, which represents a function or a value. For example, G01 X10 Y20 Z5 F100 means to move the machine in a straight line to the coordinates (10, 20, 5) at a feed rate of 100 units per minute. The letter G indicates a motion mode, the letter X, Y, and Z indicate the axes, and the letter F indicates the feed rate.

There are many codes and commands that can be used to control the machine, such as:

- G00: Rapid positioning

- G01: Linear interpolation

- G02: Circular interpolation (clockwise)

- G03: Circular interpolation (counterclockwise)

- G04: Dwell (pause)

- G20: Inch units

- G21: Metric units

- G28: Return to home position

- G90: Absolute positioning

- G91: Incremental positioning

- M03: Spindle on (clockwise)

- M04: Spindle on (counterclockwise)

- M05: Spindle off

- M06: Tool change

- M08: Coolant on

- M09: Coolant off

- M30: Program end and rewind

To edit a CNC program using codes and commands, you need to modify the existing words or add new words to the blocks. You can also use comments to annotate your program for clarity and readability. Comments are enclosed in parentheses, such as (This is a comment). Comments are ignored by the machine and do not affect the program execution.

Here is an example of a CNC program using codes and commands:

(Start of program)

G21 (Set units to metric)

G90 (Set absolute positioning)

G28 (Return to home position)

M06 T1 (Change to tool 1)

M03 S1000 (Turn on spindle at 1000 RPM)

G00 X0 Y0 Z5 (Rapid move to start point)

G01 Z-2 F200 (Plunge to depth of 2 mm at 200 mm/min)

G01 X10 Y0 F500 (Cut a line along X axis at 500 mm/min)

G03 X15 Y5 R5 (Cut a quarter circle clockwise with radius 5 mm)

G01 Y10 (Cut a line along Y axis)

G02 X10 Y15 R5 (Cut another quarter circle clockwise with radius 5 mm)

G01 X0 (Cut a line along X axis)

G01 Z5 (Retract to safe height)

M05 (Turn off spindle)

M09 (Turn off coolant)

G28 (Return to home position)

M30 (End of program and rewind)

### Software

To create a CNC program using software, you need to have a computer with a compatible application installed. There are many software options available for CNC programming, such as:

- CAD/CAM: Computer-aided design and computer-aided manufacturing software design the geometry and generate the toolpaths and G-code for your CNC machine. Some examples are SolidWorks, Fusion 360, Mastercam, and Autodesk Inventor.

- Conversational: Software that allow you to create CNC programs by answering questions and selecting options on a graphical interface, without having to write G-code manually. Some examples are Haas Intuitive Programming System, Mazak Mazatrol, and Siemens ShopMill.

- Simulator: Software that allow you to test and verify your CNC programs by simulating the machine movements and displaying the results on a virtual model. Some examples are CNC Simulator, Mach3, and NCPlot.

To edit a CNC program using software, you need to open the existing file and make the necessary changes to the geometry, toolpaths, or G-code. You can also use the software features to optimize, debug, or enhance your program, such as:

- Toolpath verification: Checking the accuracy and quality of the toolpaths and detecting any errors or collisions.

- Post-processing: Converting the generic G-code to a specific format that is compatible with your CNC machine and controller.

- Nesting: Arranging multiple parts on a single sheet of material to minimize waste and maximize efficiency.

- Engraving: Adding text, logos, or images to your parts using a special tool or technique.

Here is an example of a CNC program using software:

(Start of program)

(This program was generated by Fusion 360)

(Post processor: Generic Fanuc)

(Tool: End mill, diameter 6 mm, length 50 mm, number 1)

(Material: Aluminum, density 2.7 g/cm3, feed rate 600 mm/min, spindle speed 1200 RPM)

(Shape: Rectangle, width 10 mm, length 20 mm, depth 2 mm, corner radius 5 mm)

(Start point: X0 Y0 Z5)

(Program name: RECTANGLE)

T1 M06

S1200 M03

G00 X0 Y0 Z5

G01 Z-2 F200

G01 X10 Y0 F600

G03 X15 Y5 R5

G01 Y10

G03 X10 Y15 R5

G01 X0

G01 Z5

(End of program)

6. How to set up, run, and monitor a CNC machine safely and efficiently?

CNC operation is the process of using a computer-controlled machine to perform various tasks on a workpiece, such as cutting, drilling, milling, or turning. CNC machines can produce precise and complex shapes with high accuracy and efficiency. However, operating a CNC machine requires careful planning, preparation, and monitoring to ensure safety and quality. In this section, we will discuss how to set up, run, and monitor a CNC machine safely and efficiently from different perspectives, such as the operator, the programmer, and the supervisor. We will also provide some examples of common CNC operations and their challenges.

Some of the steps involved in CNC operation are:

1. Setting up the machine: This involves preparing the workpiece, the tools, and the machine for the operation. The workpiece must be securely clamped or fixed to the machine table or chuck, and the tools must be properly mounted and aligned. The machine must be calibrated and checked for any errors or faults. The operator must also wear appropriate protective equipment, such as gloves, goggles, and earplugs, and follow the safety rules and regulations of the workplace.

2. Loading the program: This involves transferring the program or code that instructs the machine how to perform the operation from a computer or a storage device to the machine controller. The program must be written in a specific language, such as G-code or M-code, that the machine can understand. The programmer must ensure that the program is correct and compatible with the machine and the workpiece. The operator must also verify the program and make any necessary adjustments or corrections before running it.

3. Running the machine: This involves starting the machine and executing the program. The machine will follow the program and move the tools and the workpiece accordingly. The operator must monitor the machine and the operation closely and intervene if any problems or errors occur, such as tool breakage, machine malfunction, or workpiece damage. The operator must also check the quality and accuracy of the workpiece and the operation periodically and measure the dimensions and tolerances using instruments, such as calipers, micrometers, or gauges.

4. Finishing the operation: This involves stopping the machine and removing the workpiece and the tools. The workpiece must be cleaned and inspected for any defects or flaws. The tools must be cleaned and stored properly. The machine must be cleaned and maintained regularly to prevent any wear and tear or damage. The operator must also record and report the results and the performance of the operation and the machine.

Some examples of common CNC operations and their challenges are:

- CNC milling: This is the process of using a rotating tool to remove material from a workpiece and create a desired shape or surface. CNC milling can produce complex and intricate shapes with high precision and efficiency. However, CNC milling also poses some challenges, such as tool wear, vibration, heat generation, and chip removal. These challenges can affect the quality and accuracy of the workpiece and the operation and cause damage or injury to the machine or the operator.

- CNC turning: This is the process of using a stationary tool to remove material from a rotating workpiece and create a cylindrical or conical shape or surface. CNC turning can produce smooth and uniform shapes with high speed and productivity. However, CNC turning also faces some challenges, such as tool selection, tool life, surface finish, and dimensional accuracy. These challenges can affect the performance and efficiency of the workpiece and the operation and require careful planning and optimization of the parameters and the conditions.

7. What are some of the industries and products that use CNC technology?

CNC technology is a powerful tool that can be used to create precise and complex shapes and designs from various materials. CNC stands for computer numerical control, which means that a computer program controls the movement and operation of a machine tool, such as a lathe, mill, router, or laser cutter. CNC technology has many applications in different industries and products, ranging from aerospace and automotive to medical and musical instruments. In this section, we will explore some of the most common and interesting examples of how CNC technology is used to create amazing products and solutions.

Some of the industries and products that use CNC technology are:

1. Aerospace: CNC technology is essential for the aerospace industry, as it allows for the production of high-quality and lightweight components that can withstand extreme temperatures and pressures. CNC machines can create complex shapes and curves from metals, composites, and plastics, such as turbine blades, engine parts, landing gear, and fuselage panels. CNC technology also enables the fabrication of custom-made parts for specific aircraft models and designs, such as drones, rockets, and satellites.

2. Automotive: CNC technology is widely used in the automotive industry, as it can produce accurate and durable parts for cars, trucks, motorcycles, and other vehicles. CNC machines can cut, drill, mill, and turn various materials, such as steel, aluminum, titanium, and carbon fiber, to create engine blocks, pistons, cylinders, gears, shafts, and brake discs. CNC technology also allows for the creation of intricate and aesthetic features, such as grilles, bumpers, spoilers, and logos.

3. Medical: CNC technology is vital for the medical industry, as it can create precise and sterile parts and devices that can improve the health and well-being of patients. CNC machines can manufacture surgical instruments, implants, prosthetics, orthotics, and dental devices from biocompatible materials, such as stainless steel, titanium, and ceramics. CNC technology also enables the development of innovative and personalized solutions, such as 3D-printed organs, artificial limbs, and robotic surgery systems.

4. Musical instruments: CNC technology is a great way to create beautiful and functional musical instruments, as it can carve, shape, and polish various materials, such as wood, metal, and plastic, to create guitars, violins, pianos, drums, and flutes. CNC machines can produce consistent and high-quality sound and tone, as well as unique and artistic designs and patterns. CNC technology also allows for the customization and modification of musical instruments, such as adding frets, pickups, bridges, and tuners.

8. What are some of the common problems and limitations of CNC machines and how to overcome them?

CNC machines are powerful tools that can automate and enhance the production of various products. However, they are not without their challenges and limitations. CNC machines require careful planning, maintenance, and troubleshooting to ensure optimal performance and quality. In this section, we will explore some of the common problems and limitations of CNC machines and how to overcome them.

Some of the common challenges and limitations of CNC machines are:

1. Machine accuracy and precision: CNC machines rely on precise measurements and coordinates to execute the desired commands. However, factors such as wear and tear, temperature changes, vibration, and human error can affect the accuracy and precision of the machine. To overcome this challenge, CNC machines need to be regularly calibrated and checked for any errors or deviations. Additionally, using high-quality tools and materials can reduce the chances of errors and improve the quality of the output.

2. Machine compatibility and interoperability: CNC machines use different software and hardware components to operate and communicate with each other. However, not all CNC machines are compatible and interoperable with each other, which can cause problems in data transfer, file formats, and machine control. To overcome this challenge, CNC machines need to follow common standards and protocols that ensure compatibility and interoperability. Additionally, using software and hardware that are compatible with multiple CNC machines can increase the flexibility and efficiency of the production process.

3. Machine safety and security: CNC machines pose potential risks to the operators and the environment, such as injuries, fires, electric shocks, and cyberattacks. To overcome this challenge, CNC machines need to be equipped with safety and security features that prevent or minimize the damage caused by these risks. For example, CNC machines should have emergency stop buttons, guards, sensors, alarms, and fire extinguishers to protect the operators and the environment. Additionally, CNC machines should have encryption, authentication, and backup systems to protect the data and the machine from unauthorized access or manipulation.

4. Machine cost and maintenance: CNC machines are expensive to purchase and maintain, especially for small and medium-sized businesses. CNC machines require skilled operators, technicians, and engineers to operate and maintain them. They also consume a lot of energy and resources, which can increase the operational costs. To overcome this challenge, CNC machines need to be optimized and maintained to reduce the waste and the downtime. Additionally, using cloud-based or shared CNC machines can reduce the initial and operational costs and increase the accessibility and scalability of the production process.

9. What are the benefits and future prospects of CNC technology?

In this blog, we have explored the concept, history, applications, and advantages of computer numerical control (CNC) technology. CNC is a method of controlling and operating machines with computers, which can perform complex and precise tasks with high accuracy, speed, and efficiency. CNC technology has revolutionized the manufacturing industry, as well as other fields such as medicine, aerospace, art, and education. In this concluding section, we will summarize the main benefits of CNC technology and discuss its future prospects and challenges.

Some of the benefits of CNC technology are:

1. Improved productivity and quality: CNC machines can work faster and more accurately than human operators, reducing errors, waste, and rework. CNC machines can also produce consistent and uniform products, meeting high standards of quality and precision.

2. Increased flexibility and versatility: CNC machines can be programmed to perform a variety of tasks, depending on the design and specifications of the product. CNC machines can also handle complex and intricate shapes and geometries, which are difficult or impossible to achieve with manual or conventional machines.

3. Reduced labor and operational costs: CNC machines can operate with minimal human supervision and intervention, saving time and labor costs. CNC machines can also reduce the need for multiple tools and machines, as they can perform multiple functions with one setup. CNC machines can also lower the maintenance and energy costs, as they are more reliable and efficient than manual or conventional machines.

4. enhanced safety and security: CNC machines can reduce the risk of human injury and fatigue, as they can work in hazardous or uncomfortable environments, such as high temperature, noise, or radiation. CNC machines can also protect the intellectual property and confidentiality of the product design, as they can store and encrypt the data in the computer system.

Some of the future prospects and challenges of CNC technology are:

1. Integration with other technologies: CNC technology can be integrated with other emerging technologies, such as artificial intelligence, internet of things, cloud computing, and additive manufacturing, to create smart and connected manufacturing systems. These systems can enable real-time monitoring, optimization, and customization of the production process, as well as remote control and collaboration among different machines and operators.

2. Development of new materials and processes: CNC technology can enable the development of new materials and processes, such as nanomaterials, biodegradable materials, and hybrid materials, which can offer improved performance, functionality, and sustainability. CNC technology can also enable the development of new processes, such as micro-machining, laser cutting, and water jet cutting, which can offer higher precision, quality, and efficiency.

3. Adoption and accessibility: CNC technology can be adopted and accessed by more users and sectors, such as small and medium enterprises, hobbyists, and educators, who can benefit from the advantages of CNC technology. CNC technology can also be made more affordable and user-friendly, by reducing the cost and complexity of the machines and software, and by providing more training and support for the users.

4. ethical and social implications: CNC technology can also pose some ethical and social implications, such as the impact on the environment, the workforce, the economy, and the society. CNC technology can generate environmental issues, such as pollution, waste, and energy consumption, which need to be addressed and minimized. CNC technology can also affect the workforce, as it can replace or displace human workers, creating unemployment, skill gap, and inequality. CNC technology can also affect the economy and the society, as it can create new markets, opportunities, and challenges, as well as new ethical and legal dilemmas. CNC technology can also raise questions about the responsibility, accountability, and morality of the machines and the operators.

CNC technology is a powerful and innovative technology that has transformed the way we control and operate machines with computers. CNC technology has brought many benefits and opportunities, as well as some challenges and implications, to the manufacturing industry and beyond. CNC technology is not a static or final technology, but a dynamic and evolving one, that will continue to grow and improve in the future. CNC technology is not only a technology, but also a vision, a culture, and a philosophy, that will shape the future of engineering and society.

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