Practical # 01

Practical No. 01 Objective: - Study the basics of CAD/CAM.

CAD (computer added drawing/ design):A cad system is a combination of hardware and software that enables engineers and architects to design everything from furniture to airplanes. In edition to the software, CAD system requires; •

A high-quality graphics monitor.

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A mouse, light pen or digitizing tablet.

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And a special printer or plotter for printing specification.

CAM (computer added manufacturing):CAM describes how networking system put data on the network media, how low-level errors are dealt with, and how the network polices itself. Polling, contention and token passing are three examples of CAM. Acronym for computer added manufacturing, a type of computer application that helps automate a factor. For example, the following are types of cam system, •

Real-time control

•

Robots

•

Materials requirements

The basics of CAD/CAM:-

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In product development, computer added design (cad) automates the design process while computer-aided manufacturing (cam) automates the manufacturing of cad-generated product design.

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Both system are now widely used and have transformed much of our country's manufacturing processes. Before their advent, parts were described with

technical part prints and then manufactured using traditional machine tool and machining processes.

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The use of cad then led to the use of cam, which utilizes data from cad generated prints to manufacturing a part.

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Because of this difference, these systems have divergent focuses. For example, workflow and time are not important factors in cad. But cam concerned with workflow.

Elements of CAD:Initially, CAD systems were simply electronic drawing boards and were more commonly called computer-aided drafting system because they only automated the drafting stage of a products design. Nowadays, cad is capable of automating most of, if not entire, design process and this can truncate design times, which will translate to lower costs, better quality and bolstered product performance. There are two main categories of CAD -2D cad and 3D cad systems. Twodimensional cad systems are usually little more then electronic drawing boards, providing different views of the product in various 2D planes. In comparison, 3D CDA depicts product design in three dimensions, providing a virtual prototype. 3D CAD software uses one of three molding methods 1. Wire frame molding. 2. Surface molding. 3. Soiled molding. Wire frame molding shows the part shape using interconnected line elements. Surfaces molding meanwhile, depicts the outside part geometry and in so doing. Soiled molding which is the most sophisticated form of 3D molding.

Elements of CAM:A CAM system uses CAD-generated data to create the code needed to operate a CNC machine. CAM software facilitates the programming of machine tools. It lets users define part geometry and set machining strategies, create and

confirm tool paths, and share programming data with other shop floor machines. The two basics types of CAM systems are

i.)

i.

Process-oriented

ii.

Geometry-oriented.

Process-oriented CAM systems are geared towards the process part of manufacturing engineering, which includes the effective use of tooling and machine operations, advantageous tool changes and management of complex process. Process oriented CAM system can deal with exceedingly complex processes, but they have a relatively simple concept of geometry.

ii.)

Geometry-oriented CAM systems lean toward the geometric aspects of manufacturing engineering include complex part geometries, sizeable CAD models and running process details through geometric conditions. Geometry-oriented CAM system can take on very complex geometries, but they generally have rather simple process abilities.

What is CAD/CAM? CAD/CAM is a term, which means computer-aided design and computeraided manufacturing. It is the technology concerned with the use of computer to perform certain function in design and production. This technology is moving in the direction of greater integration of design and manufacturing.

The application of computers for design:The design–related tasks performed by CAD system are: ™ ™ ™ ™ ™

Geometric molding. Engineering analysis. Design review and evaluation. Automatic drafting. Parts classification and coding.

Fundamental reasons for implementing cad system:¾ To increase the productivity of the designer. ¾ Improve communication and a data base for manufacturing.

The Application of CAM falls into two board categories: 1) Computer monitoring and control. These are the direct application in which the computer is connected directly to the manufacturing process for the purpose of monitoring or controlling the process. 2) Manufacturing support applications: These are the indirect applications in which the computer is used in support of production operations in the plant, but is no direct interface between the computer and the manufacturing process.

Standards for CAD A critical concern of CAD/CAM is the communication of design and manufacturing data within an engineering organization and between those organizations involved in the manufacture of product. The early development of technology led, however, to a number of software system and hardware types that were essentially incompatible with each other. Each system vendor used a unique data structure for the storage of the computer models. Each computer manufacturer used a different operating system and, often there were different rules or products for the communication of data between computers, and from computers to terminals and peripheral devices.

Examples of CAM For manufacturing support: 1) Numerical control part programming: control programs are prepared for automated machine tools. 2) Computer-automated process planning: the computer prepares a listing of the operation sequence required to process a particular product or component. 3) Computer-generated work standards: the computer determines the time standard for a particular production operation. 4) Production Scheduling: the computer determines an appropriate schedule for meeting production requirements. 5) Material requirement planning: the computer is use to determine when to order raw materials and purchased components and how many should be ordered to achieve the production schedule.