AutoCAD Tutorial: Part 2 • Learning Objectives: • To refresh your memories in operating AutoCAD • To practice on constructing solid model • www.siit.tu.ac.th/karndee/course/autocad.html
3D Modeling Basics • Wireframe models • Surface models • Solid models
Wireframe Model • Represents edge of actual object • Surfaces of object are not defined • Transparency and no volume • 2D objects in 3D space • Use Line, Circle, Arc
Surface Model • Edges and surfaces are defined • Object has volume but no mass • Each surface is constructed individually • Each surface is created / move to the correct orientation w.r.t other surfaces • Easier to visualize than wireframe • Can be displayed in wireframe or hidden view • Draw / Surfaces… • Command: _hide
Solid Model • A complete computerized replica of the actual object • Complete surfaces, edges, interior features of the object • Object has volume and mass • Can be displayed in wireframe or hidden view • Constructing primitive shapes Using Boolean operations to create composite solid
Primitive Solids Draw / Solids… Box Cone Cylinder Extrude Revolve Sphere Torus Wedge Boolean Operations Modify / Solid Editing… Union Joins selected solids Subtract Subtract one set of solids from another Intersect Create a solid of intersection (common volume) from the selected solids Constructive Solid Geometry (CSG) Techniques +
Part Sample(to be used in CAM section) SW Isometric View
Drawing Environments Metric unit orientation Set the drawing limit Set isometric viewpoint Primitive Solids and 2D Object Solid boxes Cylinders Rectangular Object Modification Fillet Extrude Subtract Union Move Dimensioning Common Operations
Step 0: Setup the environment • Set the environment at start up • Metric setting • Viewing in 3D • View / 3D Views / SW Isometric • Select common operations from Toolbar • View / Toolbars … • Select Solid Editing, View Point, Object Snap, Modify,
Create solid box at 0,0,0 Define size of the box: 50,50,15 x, y, z coordinate Step 1: Solid box
Step 2: Solid from 2D object • Create separate object (2D rectangular with the size 44, 44 • Round one corner: Fillet (radius of 22) • Create a solid object using Extrude feature • Draw / Solid / Extrude • Height: 5; Taper: 0)
Step 3: Solid cylinders • Create separate solid objects: 2 Cylinders: • Diameter1 = 20; Diameter2 = 10; Height = 5 • Use Subtractcommand to create a hole (Modify / Solid editing…)
Move rounded square object to the base part Use object snap to help locate the positions Subtract small box from the bigger box Step 4: Move Objects
Step 5: Move objects • Move a cylinder object to an appropriate position • Move at the base of the cylinder to 22,22,10 • Combine (Union) 2 objects
Step 6: Round Corners • Round the edges using Fillet (radius of 2)
CAD Assignment Guidelines and Minimum Requirements Section 1: Part Design Each student has to select and design an applicable part that satisfies the following conditions: • -The part must serve a least one practical purpose. • -The part must be a single solid object • -The overall dimension must not exceed W20cm xL20cm x H20cm • -The part should have at least one curve surface • -The part should have at least one hole (e.g., cylinder hole, rectangular hole, cone) • -At least one corner of the part must be rounded with indicated dimensions. • -The part should have one island • - All dimensions have to be indicated in either isometric view or in several 2 dimensional views.
CAD Assignment • The part should be able to be machined by at least two of the following operations (but not limit to): Milling, Turning, Wire cutting EDM, Die sinking, Threading, Drilling, Boring, Bending • Cleary indicate the type of material for your designed part. • Clearly indicate your name and last name in the drawing. It can be written directly on the designed part or within the drawing area.
CAD Assignment Section 2: Written Report • Each student has to submit one written report that thoroughly explains the design steps of the part. Step-by-step instructions accompanied with figures are required. The report must also explain the machining operations of the designed parts. Ground Rules and Policies • Students are required to submit CAD assignment package which include a CAD file in floppy disk (one diskette for one file) and a written report. Clearly label your name and student ID on the submitted floppy disk and report. • The CAD assignment package dues at • 4 p.m. on December 28, 05 (Wednesday). • 4 p.m. on February 8, 2006 (Wednesday) • No late assignment is accepted. • This assignment must be an individual work. Do not copy your friends. Any assignment in question will receive a zero score for CAD section. And no rework of any kind is accepted.