The document discusses computer numerical control (CNC) and its application in automation. It begins by defining CNC machining as a process that uses computers to control machine tools like lathes, mills, routers and grinders. It then explains that CNC provides precise and reliable manufacturing through programmed instructions generated by CAD/CAM software that govern the motions of CNC machines along multiple axes. The document goes on to describe different types of CNC machines, focusing on CNC milling machines and CNC lathes/turning centers. It explains the basic components and functions of these machines.

1. Assignment no.2
ROOH UL AMIN
REG NO: A1EWT-216005
SUBJECT: “PRODUCTION AUTOMATION”
PROGRAMM: B.TECH (Mech) 4 YEAR (WEEKEND)
SEMESTER: SUMMER 2016
PIMSAT KARACHI
Application of CNC in
automation industry
“Two discussions”

2. What is the CNC?
CNC Machining is a process used in the manufacturingsector that
involvesthe useof computersto controlmachine tools.
Tools that can be controlled in this manner includelathes, mills, routers
and grinders. The CNC in CNC Machining standsfor Computer Numerical
Control.
Industrialautomation and the control of its tools are provided
by Computer Numerical Controls(CNC). CNC providesfast, precise and
reliable manufacturingmethods – a requirementthat has grown
proportionately withthe rising complexity of modern industrialfabrication.
Even common consumer gadgetssuch as smartphonesand home computers
requirea level of sophistication to manufacturenotseen a few decades ago.
CNC Control Mechanism
CNC machines requireprogrammed instructionsin order for them to
function. These highly –automated instructionsfor the manufacturingprocess
are madeusing Computer-AidedDesign (CAD) and Computer-Aided
Manufacturing(CAM) software. Theinstructions are then loaded into the CNC
machine and govern its control.
The motionsof a CNC machine are moved alongat least two axes,
vertically (Y) and horizontally(X). A tool spindleprovidesdepthof movement
called the Z-axis. Movementis provided by Stepper motorsor servo motors.
Stepper motors function through powerfulelectromagnets. When a Direct-
Current(DC)charge is pulsed the motor’s electromagnets turn on the magnets
pullon the gears, movingit. CNC-controlled machinesare very preciseand
reliable. They are used in a widevariety of industrialautomation solutions
includingwelding, laser cutting, friction stir welding, ultrasonicwelding, flame
and plasmacutting, spinning, bending, gluing, fabric cutting, tape and
fiber placement, routing, picking and placing, sawing, hole-punching, pinning,
sewing and pickingand placing.

3. Types of CNC Machines
 CNC Millingmachine
 CNC Lathes
 CNC PlasmaCutters
 Electrical Discharge Machining (EDM)
 Water Jet Cutter etc.
CNC milling machine
CNC milling is a specific form of computer numericalcontrolled (CNC)
machining. Milling itself is a machining processsimilar to both drilling and
cutting, and able to achieve many of the operationsperformed by cuttingand
drillingmachines. Like drilling, milling usesa rotating cylindricalcutting tool.
However, the cutter in a milling machine is able to movealong multipleaxes,
and can create a variety of shapes, slots and holes. In addition, the work-piece
is often moved acrossthe milling tool in differentdirections, unlikethe single
axis motion of a drill.
CNC milling devicesare the most widely used typeof CNC machine.
Typically, they are grouped by the number of axes on which they operate,
which are labeled with variousletters.
1. X and Y Group
2. Z Group
3. W Group

4. 1. X and Y Group
X and Y designate horizontalmovementof the work-piece.
(Forward-and-back and side-to-sideon a flat plane).
2. Z Group
Z representsvertical, or up-and-down, movement.
3. W Group
W representsdiagonal movementacross a vertical plane.
Most machines offer from 3 to 5 axes, providingperformancealongat least
the X, Y and Z axes. Advanced machines, suchas 5-axis millingcenters, require
CAM programmingfor optimalperformancedueto the incredibly complex
geometries involved in the machining process. These devicesare extremely
usefulbecause they are able to produceshapesthat would benearly
impossible usingmanualtooling methods. Most CNC milling machines also
integrate a devicefor pumpingcuttingfluid to the cutting tool during
machining.
Virtually every typeof material that can be drilled or cut can be machined
by a CNC mill, although most of the work performed isdonein metal. As with
drillingand cutting, the proper machine tools mustbe selected for each
material in order to avert potential problems. The hardnessof the work-piece
material, as well as the rotation of the cutting tool must all be factored before
beginning the machining process.
CNC milling machine

5. CNC lathe / CNC turning center
What Is Lathe?
A lathe machine is a mechanical devicein which the work piece is
rotated against a suitable cutting tool for producingcylindricalformsin the
metal, wood or any other machinable material.
Or
Lathe is a machine that helps in shaping several material pieces in the
desired shapes. A lathe is a machine that rotates the piece on the axis in
order to perform various operations like cutting, facing, knurling,
deformation and more. Metal spinning, thermal spraying, woodturning and
metalworking are the common operations performed with a lathe machine.
Computer numerical controlled(CNC) lathes arerapidly replacing
the older production lathes (multispindle, etc.) dueto their ease of setting,
operation, repeatability and accuracy. They are designed to use
modern carbidetooling and fully use modern processes. The part may be
designed and the tool paths programmed by the CAD/CAM processor
manually by the programmer and the resultingfile uploaded to the machine,
and once set and trailed the machine will continueto turn outparts under the
occasional supervision of an operator.
The machine is controlled electronically via a computer menu style interface;
the program may be modified and displayed atthe machine, along with a
simulated view of the process.
The setter/operator needsa high level of skill to perform the process,
however the knowledgebase is broader compared to the older production
machines where intimate knowledgeof each machine was considered
essential. These machines are often set and operated by the same person,
where the operator will supervisea smallnumber of machines.
The design of a CNC lathe varies with differentmanufacturers, butthey
all have some common elements.
1. The turret
2. The spindle

6. 1. The turret
The turretholds the tool holders and indexesthem as needed,
2. The spindle
The spindleholdsthe workpieceand there are slides that let the turret
movein multiple axes simultaneously.
The machines are often totally enclosed, duein large part
to occupational health and safety (OH&S) issues.
With rapid growth in this industry, differentCNC lathemanufacturers
use differentuser interfaces which sometimes make it difficultfor operators
as they have to be acquainted with them. With the adventof cheap computers,
free operatingsystems such as Linux, and open source CNC software, the
entry price of CNC machineshas plummeted.
CNC lathe / CNC turning center