Introduction to CNC

M.E 407 Lab LecturesPrepared by Mr. Hassan Iqbal & Dr. Anwar Khalil Sheikh

Computerized Numerical Control Machining (CNC)

Introduction to CNC Machining


Objectives

To familiarize the students with Detail CNC machines terminologies CNC Machine types CNC Machine Parts Tool and Job Holding Machining setup

Lecture will be coupled with Lecture Slides, Videos, Instructors instructions and practical demonstration.

The knowledge will be review with online quiz


Topics Discussed

Introduction to CNC Brief History Safety CNC System and its Components CNC Machines (Milling and Turning in detail) Machining tools (Milling and Turning) Machining Setup


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DEFINITION

A machine tool that uses programs to automatically execute a series of machining operations. (http://www.toolingu.com/definition-900130-12155-cnc-machine.html)

The CNC term refers to a large group of these machines that utilize computer logic to control movements and perform the metalworking. (http://www.cncinformation.com/CNC-info-CNC-information-CNC-general-info/CNC-machine-tool)

CNC machines offer increased productivity and flexibility


HistoryYears HistoryLate 1940s and early 1950s The modern CNC machine design grew out of the work of John T.

Parsons. After World War II, Parsons was involved in the manufacture of helicopter rotor blades

1949 and 1952 US Air Force commissioned MIT to develop the first "numerically controlled" machine in 1949. It was demonstrated in 1952.

1956 The first NC in the Japanese private sector was developed successfully

By the 1960s The price and complexity of (NC) automated machines had been reduced to the point where they found applications in other industries.

1968 HEIDENHAIN Germany developed bidirectional counter for one axis1970-1972 First Computer Numeric Control machines were developed.1972 FUJITSU FANUC LTD was founded and became independent from

FUJITSU LIMITED. CNC was introduced. NC drill was developed2011 HEIDENHAIN Germany developed TNC 640 contouring control for

combined milling and turning operations


1959 CNC Machine: Milwaukee-Matic-II was first machine with a tool changerhttp://www.cnccookbook.com/CCCNCMachine.htm


Safety

CNC machines are fully automated systems so follow the safety

Check program on CAM software before running on machine

Wear Safety Personal Protective Equipment (PPE) Always run program first time in Single step mode Use recommended feed speed of the tool related to

material



CNC Control System

Controller- Interface- CPU- Motion control

system

Spindle motor Drive

Servo motor Drive

Servo motorSpindle motor



CNC System

Source : http://www.cncroutersource.com/breakout-boards.html


CNC System

Source : http://www.centroidcnc.com/fanuc_retrofit.html


M.E 407 Lab LecturesPrepared by Mr. Hassan Iqbal & Dr. Anwar Khalil SheikhSource : http://www.burger-web.com/ProductDescription/AKKON_USB_CONTROLLER_BOARD/Images/AKKON_CNC_CONTROLLER_Concept.png



Drives and Motors



Controller

Heidenhain Controllerhttp://www.heidenhain.us/Images/pr_images/TNC620_frontal_en.jpg

Mitsubishi Controllerhttp://wwwf8.mitsubishielectric.co.jp/cnc/english/product/cnc_m700/image04_05.html

Fanuc Controller :http://news.thomasnet.com/fullstory/CNC-Controls-aid-high-precision-nano-machining-833666



Structure of Servo Motor



Structure of Stepper Motor


Hand Wheel MPG



Ball Screw

Lead Screw vs. Ball Screw Technology



Most Commonly used CNC Machines

CNC Milling M/C

CNC Turning M/CCNC Wire EDM

CNC Die Sink EDM



CNC Vertical Milling Machine

http://www.glacern.com/index.php?page=video_index&video=1&video_name=crash_course_mill_01

Computer Numerical Control (CNC) Milling is the most common form of CNC. CNC mills can perform the functions of drilling and often turning. CNC Mills are classified according to the number of axes that they possess. Axes are labeled as x and y for horizontal movement, and z for vertical movement



Structure


Types of CNC VMC

Knee Type Bed Type


CNC Horizontal Milling Machine


Auto Tool Changer


Types of Milling ATC

Carousal ATCwww.tormach.com

Arm Type ATChttp://www.cdsindexers.com/cnc-machine-tool-products/cu-series.html#!prettyPhoto[mixed]/0/


ATC


Lathe ATC

http://www.helmancnc.com/cnc-lathe-tool-turret-introduction-for-beginners-level-cnc-machinists/


Tool Holder

Spindle Taper Types (20-30-40-50-60)


R-8 NT-40 CAT-40 BT-40

Pull Studs


High Speed Tool Holders

A type of toolholder with a short, hollow taper thatcontacts the spindle on two surfaces. HSK toolholdersprovide improved rigidity during HSM operations

HSK toolholders


Job Clamping on VMC



Milling Tools

Selection of End Milling tools

Flat End Mill CuttersFor Roughing, Semi

Roughing and finishingHigh and Low depth of cut

Ball Nose End MillFor Finishing

Low depth of cut

Bull Nose End MillFor Semi Roughing and

finishing. Low depth of cut

Face Mill

No radius on corner

Round Corners

Radius on Corners


CNC Milling Operations

Basic CNC milling Operations Drilling Tapping and Boring High Speed Milling Internal and External Threading Multi Axis Machining


High Speed Machining

(HSM) means using cutting speeds that are significantly higher than those used in conventional machining operations

Spindle RPM range 20000 ~ 40000 RPM High speed: 600-1,800 m/min, Very high speed: 1,800-18,000 m/min, Ultra high speed: >18,000 m/min.


CNC Turning Operations

Turning Operation Production operations (Tuning and milling

Simultaneously)


Turning Tools

Chip Breaker

Tool HolderCutting Insert

Turning Insert Nomenclature


Starting up CNC Machine

Homing (Milling, Turning) Job Setting on Machine

Mechanical, electronic and 3D Edge finder

Z-Height Tool Setter


Start Quiz

Introduction to CNC

Documents

Transcript of Introduction to CNC