History and Definition of CNC 202

“History and Definition of CNC” provides a fundamental overview of the development of machine control, from numerical control (NC) to computer numerical control (CNC). NC machines emerged in Industry 2.0 thanks to the invention of the ballscrew and advancements in servomotors and digital tape. Technological developments in Industry 3.0 allowed machines to directly interface with computers, resulting in the first CNC machines. Continuing advancements in digital automation and data exchange are creating new applications for CNC in Industry 4.0.

CNC machines are crucial to modern manufacturing and their importance is growing as technology advances. After taking this class, users will be familiar with the origins and defining characteristics of CNC systems. This knowledge will prepare users to learn more about, and ultimately work with, CNC machines.

Class Details

Class Name:
History and Definition of CNC 202
Version:
2.0
Difficulty:
Beginner
Number of Lessons:
15
Related 1.0 Class:
History and Definition of CNC 100

Class Outline

  • Computer Numerical Control
  • Machine Control in Industry 2.0
  • Numerical Control Machines
  • Machine Control and Program Codes
  • CNC History Review
  • Transition from NC to CNC Systems
  • CNC in Industry 3.0
  • CNC Applications
  • CNC Machines
  • NC and CNC Systems Review
  • CNC Machining Capabilities
  • CNC Advantages
  • CNC Drawbacks
  • CNC in Industry 4.0
  • Final Review

Objectives

  • Describe computer numerical control.
  • Describe the development of machine control in Industry 2.0.
  • Describe numerical control machines.
  • Describe machine control programming languages.
  • Distinguish between NC and CNC systems.
  • Describe CNC in Industry 3.0.
  • Describe CNC applications.
  • Distinguish between types of CNC machines.
  • .
  • Describe CNC machining capabilities.
  • Describe CNC advantages.
  • Describe CNC drawbacks.
  • Describe CNC in Industry 4.0.

Job Roles

Certifications

Glossary

Vocabulary Term Definition
3D Three-dimensional. Having a length, depth, and width. 3D parts are created by additive manufacturing methods.
additive manufacturing The process of joining or solidifying materials to make an object based on a three-dimensional computer model. Additive manufacturing methods typically build up layers of material to create an object.
automatic tool changer ATC. A CNC machine component that holds and changes tools during operation. Automatic tool changers reduce cycle times by automatically changing tools between functions.
Automatically Programmed Tool APT. An early programming language used in numerical control machining. Automatically Programmed Tool code is used to calculate the tool path of a specific machine task.
automation The automatic control of equipment, a process, or a system. Automation is an efficient means of performing manufacturing processes.
Axes An imaginary straight line that is used to describe the location or movement of an object in three-dimensional space. Axes in the Cartesian coordinate system include the X, Y, and Z.
ballscrew A long, threaded device that rotates to move the worktable or cutting tool of a CNC machine. Ballscrews are powered by a servomotor.
boring The process of enlarging an existing hole with a single-point tool. Boring is performed to improve the surface finish and concentricity of a hole.
CAD Computer-aided design. The use of computer software to create the design and drawing of a part, product, process, or building. CAD drawings are automated and precise.
CAM Computer-aided manufacturing. The use of computer software that facilitates the development of part programs. CAM software creates an image of the workpiece and develops the program code from information input by the programmer.
cell An arrangement of machines, tooling, materials, and operators structured around the design of similar products. CNC cells encourage smooth product flows and use space efficiently.
changeover The process of switching a machine setup from producing one part to another. Changeover takes very little time with CNC machines.
CNC Computer numerical control. A programmable system of software and hardware that controls the operation of a machine. Computer numerical control uses mathematical data to execute program instructions and direct the movement of a machine and its components.
CNC Swiss-type lathe A sophisticated machine with a sliding headstock and fixed bushing. CNC Swiss-type lathes create small, complex, cylindrical parts in one cycle.
computer numerical control CNC. A programmable system of software and hardware that controls the operation of a machine. Computer numerical control uses mathematical data to execute program instructions and direct the movement of a machine and its components.
computer-aided design CAD. The use of computer software to create the design and drawing of a part, product, process, or building. Computer-aided design drawings are automated and precise.
computer-aided manufacturing CAM. The use of computer software that facilitates the development of part programs. Computer-aided manufacturing software creates an image of the workpiece and develops the program code from information input by the programmer.
control panel The group of controls on a CNC machine that run, store, and edit the commands of a part program and other coordinate information. The control panel on a CNC machine usually consists of a keypad and display screen.
data Any information or knowledge which can be stored. Data is often kept electronically in computer databases.
depth of cut The distance that the cutting tool penetrates the surface of the workpiece. Depth of cut determines the amount of material removed with each cutting pass.
downtime An unproductive period when machine production ceases. Downtime is often due to mechanical failure, part changeover, or maintenance needs.
drive system The collection of parts that make a CNC machine move. Drive systems are made up of servomotors and ballscrews.
eight-axis machining Machine control that can execute movement in eight general directions concurrently. Eight axis machining is generally associated with CNC Swiss-type machines.
electrical logic circuitry A controlled path that contains electrical current. Electrical logic circuity transmits electricity throughout machines.
encoder A device that translates mechanical motion into a digital signal. Encoders send motion locations to a numerical display panel on a machine.
end milling A milling operation that uses a narrow cutter to machine surfaces both parallel and perpendicular to the spindle axis. End milling may cut with both the bottom and sides of the cutting tool.
face milling A milling operation in which the surface of the workpiece is perpendicular to the spindle axis. Face milling primarily cuts with the bottom edge of the cutting tool.
feed rate The rate at which a cutting tool and/or workpiece move in relation to one another during a machining operation. Feed rates can be adjusted during operation using override keys.
feedback system A method of monitoring the position of a machine tool and sending informational signals to the CNC machine control unit. Feedback systems provide information that allows the MCU to make any corrections during the cutting process.
finishing A final machining process that achieves the desired surface finish and tolerance for a part or component. Finishing is often performed on grinders.
five-axis machining Machine control that can execute movement in five general directions concurrently. Five-axis machining can be performed by cutting-edge CNC machines.
G code A programming language that pairs address letters with numerical values to form commands. G code is used to direct the operations performed by a machine.
geometric The linear and curved shapes that characterize a part. Geometric complexity is one of the key advantages of additive manufacturing.
grinder A machine that uses an abrasive to remove material from the surface of a workpiece. Grinders include surface grinders, centerless grinders, and cylindrical grinders.
hard-wired Having wires that are physically connected to other devices or wires so as to consistently function the same way. Hard-wired circuits perform the same tasks over and over again.
Industrial Internet of Things IIoT. The network of manufacturing machines that contain computer systems that send and receive data through cyberspace. The Industrial Internet of Things allows controls, sensors, and other instruments to exchange data without any human intervention.
Industry 1.0 The first major phase of manufacturing development, which lasted roughly from the 1760s to the mid-1800s. Industry 1.0 revolutionized early machine manufacturing by replacing human power with water and steam power.
Industry 2.0 The second major phase of manufacturing development that began in the late 1800s. Industry 2.0 revolutionized machine manufacturing by introducing electrical power and popularizing mass production.
Industry 3.0 The third major phase of manufacturing development that began in the late 1970s. Industry 3.0 revolutionized machine manufacturing by introducing microcomputers and developing advanced software applications.
Industry 4.0 The fourth major phase of manufacturing development that is defined by the use of machines interconnected via the Internet. Industry 4.0 revolutionizes machine manufacturing by advancing digital data exchange and automation capabilities.
lathe A machine used to create parts, often cylindrical, by removing material from a workpiece. CNC lathes are much more precise than their manual counterparts.
machine control unit MCU. A small, powerful computer that controls and operates a CNC machine. The machine control unit interprets the numerical data in the part program to guide machine movement.
machine tool A power-driven machine that uses a cutting tool to remove metal from a workpiece. Machine tools can hold a variety of cutting tools.
machining center A sophisticated CNC mill that can perform multiple machining operations in the same setup. Machining centers can hold a wide variety of cutting tools, including mills and holemaking tools.
magnetic tape A thin ribbon of material, such as metal or plastic, coated with magnetized material that can store information. Magnetic tape gradually replaced punched tape as a medium for recording and inputting data into NC machines.
mass production The time- and cost-saving process of rapidly producing a large volume of parts. Mass production is made possible through traditional manufacturing operations.
MCU machine control unit. A small, powerful computer that controls and operates a CNC machine. The MCU interprets the numerical data in the part program to guide machine movement.
mill A machine that uses a rotating multi-point tool to remove metal from the surface of a workpiece. Mills may be operated either manually or by computer numerical control (CNC).
milling A cutting operation that feeds a rotating multi-point tool along a part's surface to remove material. Milling operations are very versatile and generally produce flat surfaces.
mylar A strong, thin type of polyester film invented in the mid-1950s. Mylar is used to reinforce punched tape and magnetic tape associated with NC machines.
NC Numerical control. A system that guides machine tool components and manufactures parts using electrical logic circuitry to execute program instructions coded into tape. Numerical control was the precursor to computer numerical control.
numerical control NC. A system that guides machine tool components and manufactures parts using electrical logic circuitry to execute program instructions coded into tape. Numerical control was the precursor to computer numerical control.
operator A person trained to run a computer numerical control machine on a daily basis. Operators monitor and adjust machining operations.
part program A series of alphanumerical instructions used by a CNC machine to perform the necessary sequence of operations to machine a specific workpiece. Multiple part programs can be stored in a CNC system at one time.
part run A series of identically shaped finished products. Part runs create batches of uniform parts.
plasma cutting A method of cutting metal that uses plasma, which is a jet of gas that has been ionized by an electric arc. Plasma cutting is a quick process that creates high quality cuts.
programming language A set of symbols and rules used to present information to a processor. Programming languages are used to create programs for a CNC.
prototype A preliminary model of a part or a machine used to evaluate the look and performance of a design. Prototypes are used to determine the specifications for the final part.
punch press A machine with a stationary base and an upper arm that moves along a vertical axis to shear, bend, or form sheet metal. Punch presses are often used to perform punching and stamping.
punched tape A strip of material that uses holes that represent computer language to store data. Punched tape is an obsolete medium of data storage used to input computer commands directly into NC machines.
punching A shearing operation that creates an open hole in sheet metal by separating an interior section. Punching can be performed using a punch press.
real time The near-instantaneous interval of time that computers require to process data. Real time is virtually the same as actual time because computers process data nearly immediately.
repeatable Capable of machining parts consistently to continually deliver accurate and precise results. A repeatable process is crucial for the efficient, quality production of identical parts.
servomotor A motor in a CNC machine that powers movement of the machine tool. Servomotors rotate the ballscrew on a CNC machine, causing the table of a mill or the slides of a lathe to move.
setup All the necessary preparation of tooling and fixturing that occurs on the machine before a part program can be executed. Every part setup requires the calculation of new offsets.
software The instructions, formulas, and operations that structure the actions of a computer. Software often consists of a computer program or application.
specifications A description of the essential physical and technical properties of a part. Specifications are established either in a blueprint or directly in CAD/CAM software.
speed The rate at which the machine spindle rotates. The spindle speed affects how fast the cutting tool or workpiece moves at the point of contact.
stamping A metalworking operation that uses dies and punches to form or separate sheet metal into parts. Stamping can be performed using a punch press.
stock Raw material that is used to make manufactured parts. Stock is available in standard shapes, such as long bars, plates, or sheets.
subtractive manufacturing Any manufacturing process in which a piece of raw material is machined into a desired final shape through a controlled material removal process. Subtractive manufacturing methods are fast but create a large amount of waste.
tapping The process of cutting internal threads in a hole with a rotating multi-point tool. Tapping can be performed on a mill or machining center.
three-axis curvature data Three axis. Information that describes the motion and position of an object in three-dimensional space. Three-axis curvature data provides instructions for machine movement along three axes.
three-dimensional 3D. Three-dimensional. Having a length, depth, and width. Three-dimensional space is represented by three linear axes.
tolerances An unwanted but acceptable deviation between an actual part dimension and its intended design. Tolerances are assessed during the inspection stage of manufacturing.
toolpaths A series of program blocks that describes the movement of a single cutting tool. Complex toolpaths are typically generated using computer-aided manufacturing.
turning A cutting operation that rotates a cylindrical workpiece while gradually passing the cutting tool along the surface of the rotating part. Turning is performed on a lathe and is commonly used to create cylindrical parts.
two-dimensional 2D. Having length and width. 2D drafting is often used with CAD systems for partmaking.
vertical mill A mill with a spindle that is perpendicular to the worktable. Vertical mill worktables are parallel to the ground.
water jet cutting A cutting method that uses a powerful, high velocity stream of water to cut through materials. An abrasive can be added to the water to facilitate the water jet cutting process.
welder The power source that provides the electricity needed to perform a weld. Welders join two pieces of metal together through the application of heat.
welding A joining process that uses heat, pressure, friction, or a combination of methods to fuse two materials together permanently. Welding is used in a variety of industries from auto manufacturing to aerospace engineering.