autocad tutor solidmodel

1
AutoCAD Tutorial
Learning Objectives:
-
To refresh your memories in operating AutoCAD
-
To practice on constructing solid model
www.siit.tu.ac.th/karndee/course/autocad.html
2
3D Modeling Basics

Wireframe models

Surface models

Solid models
3
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

4
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
5
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
6
Constructive Solid Geometry
(CSG) Techniques
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
+
7
Part Sample
(to be used in CAM section)
SW Isometric View
8
Part Sample
(to be used in CAM section)
Top View
9
Common Operations
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
10
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,
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Step 1: Solid box

Create solid box
at 0,0,0

Define size of the
box: 50,50,15

x, y, z coordinate
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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)
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Step 3: Solid cylinders
•
Create separate solid objects: 2 Cylinders:
•
Diameter1 = 20; Diameter2 = 10; Height = 5
•
Use Subtract command to create a hole (Modify / Solid editing…)
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Step 4: Move Objects

Move rounded
square object to
the base part

Use object snap
to help locate the
positions


Subtract small
box from the
bigger box
15
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
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Step 6: Round Corners
•
Round the
edges using
Fillet (radius
of 2)
17
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.
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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.
19

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.