1. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 1 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Bruce Mayer, PE Licensed Electrical & Mechanical Engineer BMayer@ChabotCollege.edu Engineering 22 AutoCAD© 2D Construction-1

2. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 2 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Learning Goals  Become Proficient with invocation of AutoCAD Drawing Commands  Create Basic AutoCAD 2-Dimensional Drawing Elements e.g.; Lines, Circles, Ellipses and PolyGons  Use a Combination of ACAD 2D Elements to construct more Complex 2D Shapes

3. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 3 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Initiating AutoCAD Commands  Generally There are Three Ways to Invoke AutoCAD commands  Example – Draw a Circle 1.By PullDown Menu If you get “Stuck” in ACAD Try the ESCAPE Key

4. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 4 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Invoke Commands cont 2.By Typing the Command into the Command line  The Typed Commands often have ShortCuts  Instead of typing circle, type only c 3.Using a Tool from a ToolBAR

5. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 5 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Drawing Lines  To Random Points Type in line (or l ), or click the Line Tool Pick Points Using the Mouse – The Line follows the mouse. Click at each vertex Terminate Line by Hitting Enter or Esc  Many times these “Assisters” Help with Line Drawing SNAP GRID ORTHO OSNAP

6. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 6 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Random Pts Line This Example uses SNAP and GRID, but NOT Ortho Mouse Click Sets Vertex

7. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 7 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Closed Line  To Make a CLOSED figure of an arbitrary shape 1.Invoke line and set at least 3 Vertices 2.With Line still ACTIVE type in the command-line one of: – close –c–c Line Ready to Close Closed Line

8. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 8 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Erasing  To delete drawing elements use the Erase command  Invoke Erase by PullDown Menu Click the Erase Icon on the Modify ToolBar Type in Command line erase or e  To Erase: Start Erase Select Element(s) with Mouse Hit Enter or RIGHT Click

9. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 9 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Line by Coords  Type in the Command Line the CoOrds, one at a time  Be Sure That “Dynamic Input” is Turned OFF  Make a Box

10. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 10 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Line by Relative CoOrd  To Draw a Line RELATIVE to a Given point  Invoke the line command  ID a Starting point with the Mouse or by CoOrds  In the command Line Type Either @ x, y – x & y are CoOrds RELATIVE to the Current Point @ dist, <angle – The distance and angle (in Degrees, thakfully) Relative to Current Point

11. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 11 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Relative Lines  By X & Y  By Distance & 

12. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 12 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Construction Lines  Construction Lines are Very Useful for “Blocking In” or “Aligning” Drawing Objects  They are lines of Infinite (h) Length that may be trimmed later  Invoke Construction Line by Construction Line Tool on Drawing Tool Bar Command line → xline or xl

13. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 13 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Some Construction Lines Construction Line Options

14. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 14 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Construction Line Offset  Lets Make a Layer; Green in Color Draw some Lines Offset a Construction Line Hit ENTER twice to ReInvoke ConstrLn

15. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 15 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Drawing Circles  To Draw a circle Invoke the Command Click the Circle Tool Use the PullDown Menu: Draw → Circle → option Type in the Command Line one of – Circle or c  Command Line Text Command: circle Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: 2p

16. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 16 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Drawing Circles cont  To Draw a Simple Circle 1.Click the Circle Tool 2.Use the Mouse to Pick a Center Point 3.Do one of – DRAG with the mouse to Set the Radius – Type in a Number for the radius  Circle by Pick Center Point Drag Radius

17. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 17 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Drawing Circles cont  The Circle Command has Many useful options  Default → Center, Radius  Center, Diameter

18. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 18 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Drawing Circles cont  2 Points  Tan, Tan, Tan Start Pt  Tan, Tan Radius

19. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 19 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Circle Center Marks/Lines  Technical Drawing Practice Calls for Marks and Lines to ID Circle Centers  CenterMark Sizing Center Mark Only Center Mark & CenterLines  ACAD has many Commands and Parameters that Can ONLY be accessed thru the Command Line

20. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 20 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics SETVAR command  Typing SetVar in the Command Gives access to 480 AutoCAD System Variables Partial Listing by Setvar → ? → *  For Example, The acad.dwt has a Center mark Size of 0.09”  Use Variable DIMCEN to Change to 5X this Value Note: Can type DIMCEN w/o SetVar

21. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 21 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics CenterLines by Dim Style  The acad.dwt default for Circle Center is a MARK only; NO Lines  To Change, use Dimension Styles  Invoke the Dim Style Dialog by one of Dim Style Tool on the Dimension ToolBar PullDown Menus: Dimension → Dimension Style... Command Line → DIMSTYLE  Any of these actions Activates the Dim Style Dialog Box

22. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 22 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics CenterLines by Dim Style cont  The DimStyle Dialog Box  Select Modify... To activate next dialog Select the Symbols and Arrows Tab Check this Button to Produce CntrLns Can Use Instead of DIMCEN

23. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 23 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics CenterLines by Dim Style cont  After the change  A new Circle

24. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 24 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics POLYLINE Command  The PLINE command allows you to create "grouped" objects that can be extruded, given line width on the screen, and can contain arc segments.  To Invoke the PolyLine Command PullDown Menu: Draw → Polyline The Tool on the Drawing ToolBar Command Line: pline or pl

25. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 25 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Polyline Construction  PolyLines Are Constructed using the same methods as “Regular” Lines, but the WIDTH of the Line is VARIABLE  PLINE also has a List of OPTIONS [Arc/Halfwidth/Length/Undo/Width] Width and Halfwidth Set the Starting & Ending PolyLine width(s) Arc Helps Fine Tune PLine Arcs Length allows typing of the Next Segment Length

26. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 26 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Some PolyLines Command: pline Specify start point: Current line-width is 0.2000 Specify next point or [Arc/Halfwidth/Length/Undo/Width]: h Specify starting half-width <0.1000>:.05 Specify ending half-width <0.0500>: Specify next point or [Arc/Halfwidth/Length/Undo/Width]: Specify next point or [Arc/Close/Halfwidth/Length/Undo/Width]: Specify next point or [Arc/Close/Halfwidth/Length/Undo/Width]: Specify next point or [Arc/Close/Halfwidth/Length/Undo/Width]: *Cancel*

27. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 27 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Some PolyLines cont PLINE Specify start point: Current line-width is 0.1000 Specify next point or [Arc/Halfwidth/Length/Undo/Width]: w Specify starting width <0.1000>: 0 Specify ending width <0.0000>: 1.2 Specify next point or [Arc/Halfwidth/Length/Undo/Width]: Specify next point or [Arc/Close/Halfwidth/Length/Undo/Width]: *Cancel*

28. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 28 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Some PolyLines cont Command: pl PLINE Specify start point: Current line-width is 1.2000 Specify next point or [Arc/Halfwidth/Length/Undo/Width]: h Specify starting half-width <0.6000>:.05 Specify ending half-width <0.0500>: Specify next point or [Arc/Halfwidth/Length/Undo/Width]: a Specify endpoint of arc or [Angle/CEnter/CLose/Direction/Halfwidth/Line/Radius/Second pt/Undo/Width]: *Cancel*

29. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 29 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics SPLINE command  A spline is a smooth curve that is fitted along a number of control points  The ACAD Spline command creates a type of spline known as a NonUniform Rational B-Spline, NURBS for short  To Invoke the Spline Command PullDown Menu: Draw → Spline The Spline Tool on the Drawing ToolBar Command Line: s pline or spl

30. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 30 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics SPLINE Construction  Splines Are Constructed using the same methods as “Regular” Lines, but the segments are splined arcs Command: spline Specify first point or [Object]: Specify next point: Specify next point or [Close/Fit tolerance] <start tangent>: Specify next point or [Close/Fit tolerance] <start tangent>: Specify next point or [Close/Fit tolerance] <start tangent>: Specify next point or [Close/Fit tolerance] <start tangent>: Specify start tangent : *Cancel* Constructing a Spline

31. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 31 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics ELLIPSE command  The Ellipse command includes a number of different creation options. The default option is to pick the two end points of an axis and then a third point to define the eccentricity of the ellipse.  To Invoke the Ellipse Command PullDown Menu: Draw → Ellipse The Ellipse Tool on the Drawing ToolBar Command Line: eLLipsE or EL

32. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 32 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics ELLIPSE Construction Command: el ELLIPSE Specify axis endpoint of ellipse or [Arc/Center]: Specify other endpoint of axis: Specify distance to other axis or [Rotation]: *Cancel* ELLIPSE Specify axis endpoint of ellipse or [Arc/Center]: a Specify axis endpoint of elliptical arc or [Center]: Specify other endpoint of axis: Specify distance to other axis or [Rotation]: Specify start angle or [Parameter]: Specify end angle or [Parameter/Included angle]: ELLIPSE Specify axis endpoint of ellipse or [Arc/Center]: c Specify center of ellipse: Specify endpoint of axis: Specify distance to other axis or [Rotation]: <Ortho on> <Ortho off>

33. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 33 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics PolyLines & Ellipses  Let’s Draw some of the Elements that have many Options PolyLines Ellipses

34. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 34 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics All Done for Today Not a CAD Circle But a Boat Circle

35. BMayer@ChabotCollege.edu ENGR-22_Lec-0_2D_Construction-1.ppt 35 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Bruce Mayer, PE Licensed Electrical & Mechanical Engineer BMayer@ChabotCollege.edu Engr/Math/Physics 25 Appendix 