AutoCAD 2D: Commands, Lines, Circles, Erasing, Construction Lines, Slides of Engineering Drawing and Graphics

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Engineering 22

AutoCAD

2D Construction-

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

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

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

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

Line Ready to Close

Closed Line

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

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

Relative Lines

• By X & Y (^)  By Distance & ∠

Some Construction Lines

Construction Line Options

Construction Line Offset

 Lets

• Make a Layer; Green in Color
• Draw some Lines
• Offset a Construction Line

Hit ENTER twice to ReInvoke ConstrLn

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

Drawing Circles cont

• The Circle Command has Many useful options

 Default → Center, Radius  Center, Diameter

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

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