Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lect 12P. 1Autumn Quarter Solid Modeling Lecture 12

Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lect 12P. 2Autumn Quarter Goals 3-D CAD models developed from primitive solids Reference – Chap 11 – 3-D Geometry Concepts BTG CADKEY 99 – Chapter 6 AutoCAD 2002 Tutorial – 3-D Modeling – Chapter 6 Getting Started with 3-D CAD by Solid Modeling

Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lect 12P. 3Autumn Quarter Agenda Understand basic ways to generate 3-D solid models Create solid models from primitive shapes – usage of Solids99 or AutoCAD functions and features Derive shapes using Boolean functions Modify solids using fillets and chamfer Use Drawing Layout Mode

Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lect 12P. 4Autumn Quarter Review of important concepts in CAD CAD model is a “virtual” part A 3-D CAD model stores the entire 3-D shape of the object 3-D models can be generated from 2-D profiles by using CAD programs

Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lect 12P. 5Autumn Quarter Approaches to developing a solid model Constructive solid or primitive modeling Constraint-based modeling Feature-based modeling

Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lect 12P. 6Autumn Quarter Primitive Modeling - combine simple shapes

Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lect 12P. 7Autumn Quarter Constraint-based solids modeling Part roughed in Constrained or detailed by adding dimensions 3-D Objects created by revolving or extruding

Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lect 12P. 8Autumn Quarter Constraint-based solids modeling – by revolving

Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lect 12P. 9Autumn Quarter Constraint-based solids modeling – by extruding

Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lect 12P. 10Autumn Quarter Feature-based Modeling Creating and modifying geometric features of a solid model like a manufacturing process.

Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lect 12P. 11Autumn Quarter Example of Feature- based process

Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lect 12P. 12Autumn Quarter How Solids Models Can Be Used Improve efficiency in design by visualization and virtual assembly Link to Numerical Analysis –Stress –Heat Transfer Analysis –Fluid Flow Link to Computer-aided Manufacturing

Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lect 12P. 13Autumn Quarter Using CADKEY 99 and AutoCAD 2002 as 3-D Programs Chapter 6 introduces some of the basic techniques for creating 3-D geometry Basic models are initially built from primitive shapes – modified to create more complex objects A CADKEY 3-D blank seed drawing or AutoCAD 4-viewport template would serve as the basis for 3-D solids modeling

Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lect 12P. 14Autumn Quarter Creating Layout Mode drawings Even if the model is built with a 3D construction approach, conventional orthographic views with dimensioning and in some cases sectioning will be needed. CADKEY Chapter 6 demonstrates how to create layout mode drawings, starting with a 3D model. AutoCAD Chapters 6 and 7 show modeling, Chapter 8 shows the layout. Procedures and conventions for dimensioning will be covered later

Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lect 12P. 15Autumn Quarter Creating Layout Mode drawings CADKEY and AutoCAD have two system modes - Model mode and Layout mode. CADKEY and AutoCAD distinguish between the two so that you can create part files in Model mode, then switch to Layout mode to create different layouts of the part file and detail them for drafting purposes. In Model mode you can take advantage of all the CADKEY and AutoCAD functions to create and edit part files. Model mode is the default system mode that you enter when you start CADKEY and AutoCAD. Layout mode is a drafting tool that you use to create, dimension and then print or plot

Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lect 12P. 16Autumn Quarter Example Problem from CADKEY

Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lect 12P. 17Autumn Quarter Review Questions What are the views listed in the four view port option? What is the difference between View and WLD coordinates?