Introduction to AutoCAD Engineering Drawings April 17 Introduction to AutoCAD Engineering Drawings Dr. Kevin Wong Industrial Centre

Learning Outcomes Upon completion of the workshop, students should be able to: Explain the principle and conventional representation of engineering drawings according to engineering standards, Apply the features and functions of typical CAD systems for producing CAD drawings, Communicate through CAD drawings.

Manual Drawing Vs CAD

Introduction to CAD Computer Aided Drafting/Design Basic skills for nowadays’ Engineer Communication media among different discipline of people in different place Can be simply classify into 2 types of CAD system – 2D and 3D Some advantages of using CAD Accuracy An accuracy of up to 14 decimal places Speed Revising and editing drawings can be done quickly with minimum effort Reuse of drawing content can be done easily 3D Representation and Analysis Interference checking and 3D animations can be easily performed

Introduction to CAD AutoCAD AutoCAD2015 Free Trial AutoCAD One of the most well-known 2D CAD software developed by Autodesk Widely be used to output construction drawings for civil engineering, architecture, and building services Other applications include electrical PCB design, garment design and facility management Get a Trial Version (30-days) http://usa.autodesk.com/autocad/trial/

Engineering Drawing Created by AutoCAD

Architecture Drawing Created by AutoCAD

Starting AutoCAD Auto CAD 2015 Start up > Autodesk > AutoCAD Mechanical 2015 > AutoCAD 2015 Auto CAD 2015

User Interface (AutoCAD classic) Menu Bar Current File Name Layers Toolbar (Icon) Draw Toolbar User Coordinate System (UCS) Graphic cursor Drawing Area (Graphic Window) Status Bar X, y, z coordinate system

AutoCAD User Interface Tabs Click here to expand panel Tooltip

AutoCAD User Interface Dynamic Input The key allows you to toggle between the different input field The key allows you to display a list of valid command options Cursor Dynamic Prompt Length Dimension Current Input Field Angle Dimension

Mouse Interface Middle button Scroll to zoom in or zoom out Right button Click to activate the right click menu Left button Click the specific points and select pull down menu or graphic icon (Selection)

Keyboard Interface Enter Delete Go to next step of command / repeat last command Delete To erase lines or any sketches Spacebar Go to next step of command / repeat last command

To Set Up a Drawing Step 1: New a draw Show the Menu bar File > New > OK 1 Menu Bar 3 2

To Set Up a Drawing Step 2: Define the drawing units Format > Unit > Millimeters > OK 1 3 2 4

To Set Up a Drawing Step 3: Load the line types 1 Step 3: Load the line types Format > Line Type > Load Common used linetype: - Continuous , Hidden, Center, Dashed 2 3 4

To Set Up a Drawing Step 4: Create layer for drawing control Format > Layer > New Layer New – Create a new layer Delete – Delete a layer Current – Set the selected layer to be the active layer Color – Set layer’s color Linetype – Select/Load linetype for a layer Lineweight – Select the thickness of the line for a layer. 1 2 3

AutoCAD User Interface Draft Setting - Turn on and off the options by clicking on the buttons in the status bar Status Bar Remark: Off Status On Status Show/Hide Lineweight Grid Display Ortho Mode Quick Properties Snap Mode Infer Constraints Polar Tracking Dynamic Input Object Snap Allow/Disallow Dynamic UCS Object Snap Tracking

To Set Up a Drawing Step 5: Define the drawing limits Format > Drawing Limits 1 Specific upper right corner: E.g.: 420, 297 Specific lower left corner: E.g.: 0,0 2 Dwing Sheet Drawing Sheet 297 420

Draw Command - Line & Rectangle By specify Co-ordinates (start & end point) Dynamic input (start point, distance & angle) Command of line = l Rectangle - By specify Co-ordinates (first corner point & other corner point) Command of rectangle = rec @10,3 @10,3 10 30 0,0 0,0 0,0

Features of AutoCAD Draw with Absolute Cartesian Coordinate 0,0 *4,0 *2,3 *0,0 Absolute X-coordinate Y-coordinate Draw with Absolute Polar Coordinate 0,0 * 4<180 *4<120 *0<120 Absolute Distance Angle +Y *4<120 2,3 120o -X, +Y +X, +Y 1 2 3 180o -5 -4 -3 -2 -1 *0<120 -X +X 0,0 0,0 4,0 *4<180 1 2 3 4 5 X=0, Y=0 -2 -1 -X, -Y 0,0 +X, -Y

Features of AutoCAD Draw with Relative Cartesian Coordinate -2,1 @5,0 @0,2 @-5,-2 Relative X-coordinate Y-coordinate Draw with Relative Polar Coordinate 0,0 @ 5<0 @3<90 @5.83<211 Relative Distance Angle +Y 211o @0,2 @3<90 -X, +Y +X, +Y 1 2 3 @-5,2 -2,1 @5,0 90o -5 -4 -3 -2 -1 @5.83<211 -X +X @5<0 1 2 3 4 5 X=0, Y=0 -2 -1 -X, -Y +X, -Y

Activity 1 Write a list of relative coordinates used to draw the following figure Cartesian 0,0 .. Polar 0,0 .. 50

Activity 1 - Solution Write a list of relative coordinates used to draw the following figure Cartesian 0,0 @50,0 @0,10 @-10,0 @-30,40 @0,-60 Polar 0,0 @50<0 @10<90 @-10,0 (@10<180) @50<127 @-10<0(@10<180) @60<270 50

Zoom View > Zoom > All View > Zoom > Window April 17 Zoom View > Zoom > All View > Zoom > Window View > Zoom > In View > Zoom > Out Zoom > Window Zoom > In Zoom > All Zoom > Out

Draw Command – Circle & Ellipse April 17 Draw Command – Circle & Ellipse Circle & Ellipse Circle By specify Center point & radius Command of circle = c Ellipse - By specify Center point, first end point of axis with angle & distance of other axis Command of ellipse = el 10 10 @15<0o 0,0 0,0

Draw Command – Arc Center, Star, End Arc Center, Star, End Arc April 17 Draw Command – Arc Center, Star, End Arc Center, Star, End Arc By specify Co-ordinates (center point, start point of the arc & end point of the arc) Dynamic input (center point, radius with angle & end point of the arc) Command of arc = a 50 135 0,0 0,0 @10<0o @10<0o

Modify Command – Copy & Move Step 1. Select object to copy Step 2. Select base point Step 3. Specify the point to move Command of copy = co/cp Move Step 1. Select object to move Step 2. Select base point Step 3. Specify the point to move Command of lengthen = mo

Modify Command – Trim & Extend Step 1. Select object to act as the boundary Step 2. Select object to trim Command of trim = tr Extend Step 1. Select object to act as the boundary Step 2. Select object to extend (please noted that the location of the selected point define which side to extend) Command of extend = ex

Modify Command – Fillet & Chamfer Step 1. Type in “r” for radius Step 2. Input the radius (e.g. 10) Step 3. Select the first edge & second edges to form the radius Command of fillet = f R10

Modify Command –Chamfer Chamfer Two Distances Step 1. Type in “d” for distance Step 2. Input the first & second chamfer distance Step 3. Select the first & second lines to form the chamfer Command of chamfer = cha Chamfer Length & Angle Step 1. Type in “d” for distance Step 2. Input the first chamfer distance Step 3. Input the chamfer angle from the first line. Step 4. Select the first & second lines to form the chamfer Command of chamfer = cha First d First d Angle Second d

Practical Exercise 1 Use the (50,50) be starting point Staring Point April 17 Practical Exercise 1 Use the (50,50) be starting point Staring Point

April 17 Practical Exercise 2 Starting point B is (370,90) and use discretion for sizes not given Staring Point