Introduction To CAD/CAM

Contents• CAD / CAM• Historical Background• Conventional Product Cycle• Integration of Design and Manufacturing through CAD/CAM• Introduction to NC/CNC • CNC Machining and Turning Centers• Basics of Tooling• CAD/CAM Softwares• Delcam• PowerShape• PowerMill

Computer Aided Design (CAD)• Computer-aided design (CAD) can be a

defined as the way of creation, modification and optimization of a design by using computer system.

• By using a CAD software, we can generate– 2D draft/drawing files– 3D wireframe models– 3D surface models– 3D solid models.

Computer Aided Design (CAD)The design-related tasks performed by CAD

system are: Geometric modeling. Engineering analysis. Design review and evaluation. Automated drafting. Parts classification and coding.

Computer Aided Design (CAD)

Computer Aided Manufacturing (CAM)• Computer-aided manufacturing (CAM) is the

use of computer software to control machine tools and related machinery in the manufacturing of workpieces.

• CAM is a subsequent computer-aided process after CAD and sometimes CAE.

• The model generated in CAD and verified in CAE can be imported into CAM software, which then controls the machine tool.

Computer Aided Manufacturing (CAM)

Historical Background

WW-II: The need for more complex, accurate and precise machining was originated for then military

aerospace industry.1950s: Development of NC machines.1960s: Development of SKETCHPAD by MIT, 1st

GUI.1970s: As digital computers were invented, 2D

drafting CAD softwares were developed.

Historical Background1970s: Efforts were made to develop CAM

software, for quick NC program input. 1980s: As digital computers became more

advance and economical, solid modeling 3D CAD softwares were developed.

Late 1980s: CAD softwares became more advance, by the addition of analysis tool, e.g. Pro/ENGINEER.

Conventional Product Cycle

Integration of Design and Manufacturing through CAD/CAM

CAD CAM METHODOLOGY

Why CAD/CAM?Following are the advantages of CAD/CAM

methodology over conventional product development cycle, Shorter Lead Times. Design for manufacturing and Assembly (DFMA)

becomes very easy. Ease of use. Automation of machining operations (DNC etc..). Documentation and record. Implementation of CIM becomes easy.

Basics of NC/CNC • NC stands for “Numerically Controlled”• Numerical Control is a form of programmable

automation in which the mechanical actions of an equipment are controlled by alphanumeric data instructions.

• The set of data instructions, which is required to produce a part is called as a part program.

• The program is translated into appropriate electrical signals for input to motors that run the machine.

Why NC Machines were Developed To achieve

Flexibility to manufacture complex or impossible jobs at lesser cost

Improvement in the accuracy and quality of manufactured parts

Automation and repeatability Reduction of non-cutting time in the machining cycle

Prototype of NC Milling Machine Developed By MIT

Controller

Machine Tool

Basic Components of NC System An NC system consists of three basic components,

a) Program of Instructionsb) Machine Control Unit (MCU)c) Processing Equipment

ProgramMachine Control Unit

Processing Equipment

Layout of Punched Cards NC MachinePart Drawing

Equipment for part programming

Punch Tape MCU, that converts part programming into

electric signalsMachine Tool

CNC Part Programming• CNC part programming contains geometric

data about the part and movement commands of the cutting tool with respect to the work piece.

• Preparatory functions (G-Codes) are associated with tool movements.

• Miscellaneous functions (M-Codes) are associated with other auxiliary machine functions, such as coolant on/off function, fixture clamping, etc.

Methods of CNC Part Programming• Following are the various methods of CNC part

Programming.– Manual Part Programming (MDI)– Computer-Assisted Part Programming– CAD/CAM-Assisted Part Programming

Machining Center & Turning Center• A machining center is highly automated

machine tool capable of performing multiple machining operation under CNC control.

• It is an advanced form of CNC Milling machine, having ATC and APC.

• A turning center is capable of performing various turning operations under CNC control.

• It is an advanced form of CNC Lathe machine, having ATC, workpiece gaging, and tool monitoring

CNC Machining Center

CNC Turning Center

Basics of Tooling

CAD/CAM Softwares• Solid Edge• SolidWorks• Catia• Pro/ENGINEER• AutoCAD• Unigraphics NX• Delcam• Mastercam

Applications of CAD/CAM• Engineering & Machining– Automated machining– Tool making– High Speed machining, etc..

• Transport Industry• Plastics & Packaging• Footwear & Consumer products• Dental and Orthotics• Reverse Engineering and rapid prototyping

Delcam• Delcam is one of the world's leading suppliers

of advanced CAD/CAM software product development solutions for the manufacturing industry.

• PowerShape is a Delcam CAD Package• PowerMill is a Delcam CAM Package

PowerShape Environment

PowerMill Environment

Capabilities of CAM Software• Manufacturing Processes Development• Generation and verification of tool path• Prototype development• CNC Programming• Tool path optimization• Effective machining strategies to reduce cost

and time• Integration of CAD/CAM data for efficient data

management

Output of CAM Software

• NC Coding• Animation