CAD/CAM and Computer Use in Manufacturing

• CAD/CAM means computer-aided design and computer-aided manufacturing.
• CAD/CAM technology applies digital computers to design and manufacturing functions.
• CAD/CAM aims for greater integration of design and manufacturing, leading to fully automated factories.

Role of Computers in Industrial Manufacturing

• Products have characteristics that meet customer requirements or expectations (e.g., power loss, breaking strength).
• Product quality relates to the societal impact during its lifecycle.
• High-quality products minimize the loss to society throughout their lifecycle.
• There is a need to optimize product design, reduce costs, improve production, meet delivery times, and increase flexibility in manufacturing systems.
• The roles of computers in manufacturing is pre-processing support, monitoring & control, and post-processing support.
• Pre-processing support includes computer-aided design/drafting and finite element analysis.
• Pre-processing support includes computer-aided part programming, process planning, scheduling, tool design, and material requirement planning.
• Computers indirectly support manufacturing through part programming, process planning, time standards, and production scheduling.
• The computer is directly interfaced with manufacturing for process monitoring or control.
• Monitoring involves direct computer interface for observing and collecting data from the manufacturing process.
• Controlling involves monitoring and controlling the process based on observations, issuing command signals based on control algorithms.
• Post-processing consists of functions that enable delivering quality products to customers.
• Post-processing includes computer-aided assembly, inspection/quality control, cost analysis, packing/labeling, market feedback analysis and billing.
• The use of computers represents a methodological approach for product development and manufacture, supported by enabling technologies.

CAD

• CAD is a design process using computer graphics and software for analytical, costing, and ergonomic aspects.
• After a conceptual design emerges, the geometric model can be started.
• The choice of a geometric model depends on the type of analysis required
• CAD systems use a definition translator to convert designer input into the proper database format.
• Interface algorithms extract required data from the model database for engineering analysis.
• Finite element analysis uses specific algorithms for system modeling.
• Design testing and evaluation may lead to geometric model changes before finalization.
• The final design leads to drafting/detailing, documentation, and production of final drawings.

CAM

• CAM involves computer systems to plan, manage, and control manufacturing plant operations through direct or indirect computer interface.
• CAM can be acheived through either direct or indirect computer interface with the production resources of the plant
• The geometric model from CAD is the basis for CAM.
• Interface algorithms extract information from CAD for CAM activities.
• NC programs, ordering tools/fixtures result from process planning.
• Parts undergo computer-aided quality control.
• Real part image is compared to a master image in the model database.
• The parts are assembled by robots after passing inspection.

Product Lifecycle

• Product lifecycle starts with a concept driven by customer and market demands.
• The product is evolved through the design engineering process.
• Traditional lifecycle involves releasing part prints after design for production.
• Production engineering assesses feasibility and process planning aims for lowest cost.
• There is a need for implementation such as tool making, equipment acquisition, raw material procurement, and operational instructions.
• The computer-aided manufacturing (CAM) environment also includes design and manufacturing processes.
• The product lifecycle in a computer-aided environment begins with identifying a need.
• Synthesis determines a product's philosophy, functionality, and uniqueness.
• Synthesis information is primarily qualitative
• Conceptual design is the end goal of synthesis
• Analysis uses engineering principles to evaluate product performance.
• Quality of analysis is based on the quality of the design model.

Manufacturing Industries

• Manufacturing industries differ in how the product cycle is implemented.
• Industries are classified based on quantity of product, physical facility arrangement, and manufacturing automation.

Types of Production

• The four types of production are job shop, batch, mass, and continuous flow.
• Job shop production involves low volumes and high variety, requiring flexible equipment.
• Batch production involves medium lots produced once or at regular intervals.
• Mass production involves very high volumes with dedicated equipment.
• Continuous flow involves continuous dedicated bulk manufacturing.

Types of Plant Layout

• Plant layout involves arrangement of physical facilities.
• Fixed position layout: the product remains in one location due to its size and weight.
• Process layout: production machines are grouped by manufacturing process.
• Product flow layout: plant facilities arranged for one product or product class in large volumes.

Types of Automation

• Automation uses mechanical, electrical, electronic, and computer-based systems to operate and control production.
• Automation types include fixed, programmable, and flexible automation.
• Fixed automation: sequence of operations is fixed by equipment configuration.
• It is the integration and configuration of many operations into one piece of equipment
• Programmable automation: machinery can change operation sequence for different products.
• The operation sequence is controlled by a program.
• Flexible automation: capable of manufacturing a variety of products or parts.
• It is continuous production of variable mixtures of products or parts

Applications of CAD/CAM

• CAD/CAM enables modeling of complex products, editing existing geometry, drafting, and documentation.
• Analysis includes stress-strain, heat transfer, dynamic analysis, and optimization, often using finite element analysis.
• Evaluation includes automatic dimensioning routines, inference checking, and kinetic routines to test mechanical linkages.
• CAD/CAM aids in product design, creating a database for manufacturing.
• Computer-aided process planning (CAPP) aims to production planning.
• Interactive graphics NC part programming is also possible with CAD/CAM
• Computerized systems have been developed production planning
• Material requirements planning determines when materials/components should be ordered.
• Shop floor control connects the computer directly to the manufacturing process for monitoring.
• Computer-aided inspection ensures the product quality.