Lecture 04A - Design Isometrics and Intro to AutoCAD

Engineering H191 - Drafting / CAD

Gateway Engineering Education Coalition Lect 4 P. 1Autumn Quarter

Design Review, Isometric Drawings and Introduction to AutoCAD

Lecture 4



Topics For Today

• Using the Engineering Design Process (Review - Preparation for Lab)

• More Freehand Sketching– Isometric Sketches

• Introduction to AutoCAD 2002– (You should have read Lesson 1 by now!)



Topics For Today

• Suggestions For Leisure Reading– “All Corvettes Are Red”– “The Soul Of A New Machine”– “To Engineer Is Human”

• Hands-on Lab Tomorrow – HI 208– READ TWTW, pp. 8-23

(or pp. 10-27 in 1st Ed.)



FEH Program Web Page

• The FEH program web page may be found at: http:// feh.eng.ohio-state.edu

• Read lab write-up Tonight!– Click on Labs Link on FEH Homepage



FEH Homepage

Labs

Labs



Engineering Design Process

• AS DEFINED BY BERTOLINE ET. AL.

• IDEATION• REFINEMENT• IMPLEMENTATION

• You will do it all in Lab this week



Design

• What is design?– PROCESS OF CONCEIVING OR INVENTING

IDEAS – Start w/ brainstorming for this lab• The Art of Design– DESIGN FOR FUNCTION AND PURPOSE

• The Practice of Engineering Design– PRODUCT DESIGN



Isometric Sketching – Example & Ellipses

Goals• A process for creating isometric drawings• A process for sketching ellipses for isometric

drawings

Reference• BTG Chapter 5



30o 30o

60o60o

Isometric Axis

Making an Isometric Sketch- Defining The Axis



DepthWidth

Height

Isometric Axis Convention

Making an Isometric Sketch- Axis Convention



Object for Practice

How would you sketch this object?



Front Face

Height

Width

Blocking in the Object– Begin with Front Face

Start with Isometric

Axis



Height

Depth

Side Face

Blocking in the Object– Add Side Face



Top FaceBlocking in the Object

– Add Top Face



Adding Detail – Cut Outs – Part 1



Adding Detail – Cut Outs– Part 2



Adding Detail – Cut Outs– Part 3



Darken Final Lines



Isometric ellipses

• In an isometric drawing, the object is viewed at an angle, which makes circles appear as ellipses.

• Holes

• Cylinders



Ellipses can be in any plane



Sketching an Isometric of a Hollow Pipe



Step 1 - Creating the Base Box

Diameter

Diameter

Length



Step 2 – Ellipse on Front Face

Lines to Tangent Points

- lines to tangent points

- corner to corner to get center

Tangent Points



Step 3 – Ellipse on Front Face

Tangent Points

Sketch in Arcs



Step 4 – Ellipse on Back Face and Profile

Draw Tangent Lines for ProfileComplete Visible Part of Back Ellipse

Repeat for ellipse on rear face



Step 5 – Ellipse for Hole on Front Face

Create Box for Hole

Sketch Ellipse



Isometric of Hollow Pipe



Defining Hidden and Center Lines

• Hidden Line – used to represent features that cannot be seen in the current view

• Centerlines – used to represent symmetry and to mark the center of circles and the axes of cylinders, and the axes of symmetrical parts, such as cylinders and bolts



Example

Visible LineCenter Line

Hidden Line



Precedence of Lines

VISIBLE LINE takes precedence over all other lines

HIDDEN LINE and CUTTING PLANE LINE take precedence over center lines

CENTER LINE does not have precedence



Example Application of Precedence



Engineering Drawings

• Drawing• Borderline and Title Block– Borderline – Space outside left blank so details

are not lost if the edge of the drawing is torn– Title Block – Information about who did the

drawing, when it was done, where it was saved



AutoCAD 2002

• A 2D drawing and 3D modeling package

• Will learn to use the software through a variety of guided exercises and homework assignments

• Today's Lesson– Geometric Construction Basics



AutoCAD Startup Screen

This is the opening screen for AutoCAD 2002This is the opening screen for AutoCAD 2002



AutoCAD Toolbars

Object Object Properties Properties

ToolbarToolbar

Standard Standard ToolbarToolbar

Pull-down Pull-down MenusMenus

Draw ToolbarDraw Toolbar

Modify ToolbarModify Toolbar

Graphics Graphics CursorCursor

Graphics Graphics WindowWindow

Command Command LineLineCursor Coordinate Cursor Coordinate

DisplayDisplay



Today’s Drawing

This is This is object object that that

will be will be drawn drawn todaytoday



AutoCAD Title Block

• For each drawing that you turn in, you will need to insert a title block

• STEPS– Complete the drawing– Go to Layout 1

• Click OK when the window pops up– Use the Insert Command [INSERT]

• Select the file “TITLE BLOCK”• Select Explode the Title Block (so you can edit)

– Use the Edit Command to change the text [ED]



TB – Step 1Drawing Drawing

is is CompletComplet

ee

Layout1Layout1



TB – Step 2

Select OKSelect OK



TB – Step 3TITLEBLOCKTITLEBLOCK

Select OKSelect OKExplode - YesExplode - Yes

INSERT INSERT CommandCommand



TB – Step 4

Enter TitleEnter Title

EDIT CommandEDIT Command

Click on TextClick on Text

* Repeat for each * Repeat for each Field *Field *



TB - Complete

CompletCompleted ed

DrawingDrawing

Print Print PreviePrevie

ww



AutoCAD 2002 – Lesson 2

• Work through the lesson at your own pace• Ask questions as they come up• Once the Guide Plate is drawn and has a Title

Block, print it and turn it in.• Draw Exercise 2 – this will be Drawing 7• Think about what you are doing while you follow

the steps.• Goal - be able to draw without the book!!



Assignments

• Dwg 7 – Lesson 2, Exercise 2 (page 2-23)– Save as MOUNT BLOCK– Due at end of class today

• Dwg 8 – G15– Sketch a pictorial view of each object– Due at the beginning of the next lecture

Documents

Lecture 04A - Design Isometrics and Intro to AutoCAD