CAD/CAM

• CAD


  Computer Aided Design - Covers all functions involved in designing a product for fabrication
• CAM


  Computer Aided Manufacture - All functions involved in producing a product
• CIM


  Computer Integrated Manufacture - Integration of the total manufacturing enterprise through the use of computer integrated systems and data communications coupled with new managerial philosophies that improve organizational and personnel efficiency
• CAD/CAM/CIM Acronyms


  • CAD
  • CAM
  • CIM
• Automation Timeline


  • Manual drafting
  • Group technology (1920)
  • 2-D CAD
  • Computer-aided process planning (CAPP)
  • Computer-aided engineering (CAE)
  • Programmable logic controllers
  • Flexible manufacturing systems
  • RISC computers
  • IBM PC-based CAD & CAM
  • Fully integrated system software
• The Design Process


  1. Collecting design definitions, relevant design information and feasibility study

  2. Analysis

  3. Synthesis
• The CAD Process


  1. Design conceptualization

  2. Design modeling and simulation

  3. Design analysis

  4. Design optimization

  5. Design communication and documentation
• The Manufacturing Process


  1. Process planning

  2. Production planning

  3. Production control

  4. Quality

  5. Packaging

  6. Shipping
• The CAM Process


  1. Design and procurement of new tools

  2. NC, CNC, DNC programming

  3. Order material

  4. Marketing
• Design Process


  • Collecting design definitions, relevant design information and feasibility study
  • Analysis
  • Synthesis
• CAD Process


  • Design conceptualization
  • Design modeling and simulation
  • Design analysis
  • Design optimization
  • Design communication and documentation
• Manufacturing Process


  • Process planning
  • Production planning
  • Production control
  • Quality
  • Packaging
  • Shipping
• CAM Process


  • Design and procurement of new tools
  • NC, CNC, DNC programming
  • Order material
  • Marketing
• The design process and the role of CAD
• Model transformations in design
• Representations in design evaluation
• The use of models in design
• CAD system architecture


  Hardware, software, data, human knowledge and activities
• Elements/functions of a CAD system

  • Model definition
  • Model manipulation
  • Picture generation
  • User interaction
  • Database management
  • Applications
  • Utilities
• Common databases as linkage to various computerised applications
• Some important applications of CAD

  • 2-D design
  • Geometric models
  • Analysis
  • Documentation
  • Manufacturing
  • Management
• Classification of geometric models
• The various types of surfaces used in geometric modelling
• Ruled surface generation
• Coons surface generation
• Bezier curve and associated control polygon
• Modification of Bezier curve by tweaking the control points
• The spline curve
• Feature model and geometric model
• Ruled Surface


  A surface generated by moving a curve along another curve
• Coons Surface


  • Defined by 4 curves
  • Generates a smooth surface
• Bezier Curve


  A parametric curve defined by a control polygon
• Bezier Curves


  • Depend on the associated control polygons
• Modifying Bezier Curves


  By tweaking the control points
• Spline Curve


  A piecewise polynomial curve
• Feature Model


  Describes the shape, dimensions, geometric constraints and entities
• Geometric Model


  Associated with the feature model, contains the geometric and topological entities
• Parametric/Variational Design Process


  1. Create basic part model

  2. Specify dimensions as variables

  3. Specify geometric constraints

  4. Evaluate model

  5. Create variants by manipulating variables
• Wire-frame models are ambiguous while solid models are not
• Parametric design and variational design allow creating variants of a model by manipulating parameters