MIT OpenCourseWare http://ocw.mit.edu 4.510 Digital Design Fabrication Fall 2008 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms.Lecture 2 Background on Design and Digital Manufacturing Prof. Larry Sass Department of Architecture Computer modeling = Description – Geometry – Application of Geometry to a Design problemTerminology • CAD Computer Aided Design • CAM Computer Aided Manufacturing • CAE Computer Aided Engineering • CNC (NC) Computer Numerically Controlled MachinesOrigins of CAD/CAM 1952 • Numerical Control machines are widely used to operate a toolpositioning through computercommands. MIT’s Servo Mechanisms Laboratory demonstrated anumerically controlled 3 axis milling machine. 1959 • Control digital computer. The first application of a control using a digitalcomputer occurred at a Texaco refinery located in Port Author Texas where a catalytic cracking unit wasoptimized using a linear programmingalgorithmOrigins of CAD/CAM 1960 Robotic Implementation – The precursor to widespread use of robots in manufacturing processes 1970 Computer Numerical Control – The advent of the mini computer where tools could have there own memory. 1980 Flexible Manufacturing System – The idea of sets of machines to make a relatively wide variety of products with automatic movement of products through any sequence of machines this lead to Computer integrated Manufacturing 2000 Variety of Machine Sizes and TypesCBA Fab Labs cba.fab.mit.edu India South Africa Ghana NorwayBasic Components of an NC Machine [1] [2] [3] Program Machine Control Processing EquipmentUnit1952 – MIT Servo Lab – Numerically Controlled Machines – Began with the US Air Force – The work Started at the Parsons Lab in the 1940s – Developed the idea of Positional Data on Punch Cards – 1949 MIT Servomechanism Laboratory to develop a prototype – The first NC machines was presented in 1952 – 3 Axis milling machine – Work led to the development of the APT (Automatically Programmed Tooling)Basic Components of an NC Machine [1] [2] [3] Program Machine Control Processing EquipmentUnit[PROGRAM] Origins of CAD 1963 MIT1963 – Sketch Pad A Man Made Graphical Communication System Parametric Modeler for Engineers - Small changes to existing drawings - Great for the creation of small scientific operations that can only be understood graphically - For highly repetitive drawingsDesign Descriptions Lines Surface Solid NURB Parametric Models Modeling Surface Modeling ModelingDesign Description Discovery 1960s 1970s 1980s 1960s-80s 80sDescriptions for Fabrication Principles of Making 1 - Measure 2 - Cut or Build 3 - AssemblyDescriptions for FabricationDesign Description 1960s 1970s 1980s 1960s-80s 1980 2000AnalogueDigitalProduction Systems Symbolic System 1973 Carnegie Mellon •A production system is a •Symbolic Production System – Artificial schema for specifying an Intelligence – Text based outcomes (the information processing system. web) – Q. Do you know which restaurant you want to go to? – A. No – Q. Is there any kind of food you would particularly like? – A. No – Q. Do you like spicy food? – A. No • A→BProduction Systems Shape Production System 1975 UCLA & Open University • A Shape Grammar is a Visual Production System Shape Rule Application or Derivation ResultA Physical Production System • Physical Design Grammar – A physical design grammar is a production system withdescriptions as object opposed tolayers • Benefits: – Cross scale production – Working Models - Reflect the behavior of a building not itsimage • Challenges: – Compliant subdivision of an initial shape – How to manage construction behaviorsSummary • Background – CAD was invented to run CNC machines • Drawings are after effects • Parametric modeling was invented by Ivan Sutherland in 1963 – Design Description = CAD document (Compliant) • CAD Programs were used to generate information for machines – 1960’s • CAD Programs were used to generate information for visualization 1980-2000 • CAD programs will be used to generate information for fabrication – Production Systems • Text • Shape • Objectfuture • Procedural Processes – Algorithms for Production – Jove – Medical – Grammars for