 Computer-aided design (CAD) is the use of computer systems to assist in the creation, modification, analysis, or optimization of a design.  Computer-aided manufacturing (CAM) is the use of computer systems to plan, manage, and control the operations of a manufacturing plant through direct or indirect computer interface with plant’s resources.

To increase productivity of the designer To improve quality of the design To improve communications To create a manufacturing database To create and test tool paths and optimize them To help in production scheduling and MRP models To have effective shop floor control

Delineation of geometric model Definition translator Geometric model Design and Analysis algorithms Drafting and detailing Documentation To CAM Process Interface algorithms Design changes

Design phaseRequired CAD tools Design conceptualizationGeometric modeling techniques; Graphics aids; manipulations; and visualization Design modeling and simulationSame as above; animation; assemblies; special modeling packages. Design analysisAnalysis packages; customized programs and packages. Design optimizationCustomized applications; structural optimization. Design evaluationDimensioning; tolerances; BOM; NC. Design communication and documentation Drafting and detailing…

Geometric model Interface algorithms Process planning Inspection Assembly Packaging To shipping and marketing NC programs

Manufacturing phaseRequired CAM tools Process planningCAPP techniques; cost analysis; material and tooling specification. Part programmingNC programming InspectionCAQ; and Inspection software AssemblyRobotics simulation and programming CAM Tools Required to Support the Design Process

Computer graphics concepts Design tools Geometric modeling CAD tools

Design tools + Computer Hardware (control unit; display terminals; I/O devices Software (graphics; modeling; applications programs = CAD tools

Networking concepts Mfg tools CAD CAM tools

Definition of CAM Tools Based on Their Implementation in a Manufacturing Environment Mfg tools + Computer Hardware (control unit; display terminals; I/O devices Software (CAD; NC; MRP; CAPP…) = CAM tools Networking

Definitions of CAD/CAM Tools Based on Their Constituents Mfg tools Networking Design tools Geometric modeling Computer graphics concepts CAD/CAM tools

Definition of CAD/CAM Tools Based on Their Implementation in an Engineering Environment Design and Mfg tools Hardware Software = CAD/CAM tools Networking + Computer

Geometric modeling of conceptual design Is design evaluation Possible with available Standard software? Design testing And evaluation Is final design Applicable? Drafting Documentation Process planning Are there manufacturing discrepancies in CAD databases? NC programming Machining Inspection Assembly Develop customized programs and packages No Yes Geometric modeling and graphics package Design package Programming package No CAPP package NC package Inspection And Robotics package Typical Utilization of CAD/CAM Systems in an Industrial Environment

The Manufacturing Process The Design Process Synthesis Analysis The CAD Process The CAM Process Design needs Design definitions, specifications, and requirements Collecting relevant design information and feasibility study Design conceptualization Design modeling and simulation Design analysis Design optimization Design evaluatio n Design documentation and communication Process planning Order materials Design and procurement of new tools Production planning NC, CNC, DNC programming Production Quality control Packaging Marketing Shipping Typical Product Life Cycle

System hardware OVERVIEW OF PENTIUM PC The hardware of a Pentium computer consists of the following: i. Mother board ii. Hard disc/floppy disc controller card iii. Graphics adapter card iv. Input/Output card v. Switch mode power supply vi. Floppy disc drive vii. Hard disc drive viii. CD-ROM drive

GRAPHICS SYSTEM Graphics system consists of four subsystems: a. Geometry engine subsystem b. Scan conversion subsystem c. Raster subsystem d. Display subsystem

RASTER SUBSYSTEM The raster subsystem will have usually 24 bit planes. This will provide eight bit planes for each primary color (RGB) so that (28) shades of a single color can thus obtain. Since the different colors are obtained by the three primary colors a total of (28)3colors are available on the screen. In a typical raster engine five 256K X 4D RAM provide 4 bits of Z-depth. The raster information is stored in the frame buffer. Twenty 64 K X 4 video RAM provide 4 bits for each pixel of 1280 X 1024 resolution. Entry level systems will have 12 bit planes and high end systems will have 32 bit planes for the frame buffer. These provide the color and depth for the images.

INTERACTIVE DISPLAY DEVICES The display devices be can classified into two groups: i. Display devices based on CRT principle ii. Flat screens Most interactive CAD systems use CRT based graphic monitors. CRT is a glass enclosed tube in which a finely focused electron beam is deflected to a phosphor coated screen. The screen then glows to produce a visible trace when excited by impinging electrons

DISPLAY DEVICES BASED ON CRT The position of the visible trace on the CRT screen is controlled by a focusing system and a set of horizontal and vertical deflection plates as shown in Fig CAD/CAM/CIM In a color CRT, there are three electron guns, one each for red, green and blue. The phosphor dots for red, green and blue are arranged in a triangular pattern. The individual beams intersect at a shadow mask which directs a red beam to a red phosphor dot and so on.

RASTER SCAN TECHNIQUE A raster CRT graphics device can be considered a matrix of discrete cells each of which can be made bright. Thus it is basically a point plotting device. If a line is to be drawn, it can be approximated by a series of dots close to the path of the line. Figure 4.13 illustrates this concept.

Since the raster CRT is an analog device, it requires an electrical voltage and the digital data of the frame buffer has to be converted to an analog voltage through a digital to analog converter (DAC). This is schematically shown in Fig

The color graphics monitors are usually referred to as RGB monitors since the different colors are obtained by mixing three primary colors, Red (R), Green (G), and Blue (B). A simple color frame buffer can be implemented with three bit planes, one for each primary color.

Each bit plane drives as individual color given for each of the three primary colors. This arrangement can lead to eight colors as given in the Table

INPUT DEVICES KEYBOARDA TOUCH SCREENS JOYSTICKS TRACK BALLS MOUSE DIGITIZER OUTPUT DEVICES (also known as hardcopy devices) PLOTTERS PRINTERS

Here are some different storage devices: Pen Drive CD DVD Blu-Ray disk Hard disk Floppy disk USB Devices Memory Card Multimedia Card RAM ROM Tape Drive Cloud storage Flash memory

TRANSFORMATION IN GRAPHICS  Geometric transformations provide a means by which an image can be enlarged in size, or reduced, rotated, or moved.  These changes are brought about by changing the co-ordinates of the picture to a new set of values depending upon the requirements.

2-D TRANSFORMATIONS  In computer graphics, drawings are created by a series of primitives which are represented by the co-ordinates of their end points.  Certain changes in these drawings can be made by performing some mathematical operations on these co-ordinates.  The basic transformations are 1.Scaling 2.translation 3.rotation. 1. SCALING Changing the dimensions of window and view port, it is possible to alter the size of drawings. In general, this can be done by multiplying the co-ordinates of the drawing by an enlargement or reduction factor called scaling factor, and the operation is called scaling.