Civil 114 Civil Engineering Drawing AutoCAD Drawing a flowchart

“GRID” and “SNAP” Turn on grid display (F7) or click the “GRID” button on the status bar. Press (F9) to turn “SNAP” on/off. (0,0) (420,290)

“GRID” and “SNAP” settings Right click “GRID” on the status bar, select “settings”. Default value of the grid’s X, Y spacing is 10 drawing units in each direction.

Draw a rectangle Turn on grid display (F7) and snap (F9). Draw a rectangle of size 50x30, with its lower-left corner at (100,100).

“LIMITS” Sets the limits of the grid display. If you turn on the grid, you will see the limits. Most often, the default limits will be changed (or simply ignored) subsequently. The reason is that, in most cases, civil/ structural drawings are drawn 1:1 when using CAD and the dimensions are in mm, hence, 420x297 is seldom large enough (e.g. length of a beam = 10000). There is no problem to draw outside the default limits

CIRCLE type C, or select Draw – Circle – (options), or use Circle button on Draw Toolbar. Try these different options: Center + Radius (most common option) Center + Diameter (press D to change to diameter option) 3 Points (useful in surveying), etc.

ELLIPSE type ELLIPSE, or use pull-down menu, or use button on Draw Toolbar. Try these two options: provide major and minor axes endpoints, or provide Center (C), followed by major and minor axes

Draw the rectangle and ellipse as shown below: Steps: Draw a rectangle Turn OSNAP on – Settings – MID (midpoint) From pull-down menu: Draw – ellipse – Axis, End

POLYGON POLYGON: 3 to 1024 sides of equal length Give # of sides (e.g. 5) and center point (“a” in figure below), then choose either I option: Inscribed inside an imaginary circle, or C option: circumscribed about imaginary circle Give radius (e.g. by clicking point “b” in figure) or use Edge option: specify start and end point of an edge Circumscribed Inscribed a b Edge start point Edge end point

Exercise: Steps: 1. Draw a 5-sided polygon 2. Draw the inside circle (Circle—Tan,Tan,Tan) 3. Turn on OSNAP; (Osnap—setting—endpoint) 4. Draw the outside circle (Circle—3 points)

ARC Arc: Start point – Second point – End point Start point – Center point – Angle (AutoCAD: angles: anticlockwise = +ve by default) Start point – Center point – End point Second End Start Center Angle = 75

MTEXT Draws multi-line text Click the “A” button on Draw Toolbar. Specify width of paragraph by a box; vertical length is unlimited and will depend on amount of text written Select font, justification, etc. and type in text as if using a word editor. Choose appropriate text height (it’s in drawing units). Click “OK” when done

Exercise: After MTEXT command is completed, you can still change its appearance or/ and contents. Just double-click the text to start the change (or use DDEDIT command)

COPY Copy (CP) command (3-ball button on Modify Toolbar): Use Line to draw a star with one corner at a grid point. Turn snap (F9) off, and Copy (CP) the star (select all lines forming the star) Try different methods of copying: Give Base point (“where your hand holds it”): turn snap on (F9) and pick a tip of the star, and then 2nd point (“where your hand releases it”): at another grid point Alternative method: Give the displacement vector (of everything) by clicking any point (“tail” of displacement vector), then specifying the second point (“head”) using relative coordinates (e.g. @8<0 to copy things to 8 units to the right); Press enter to stop copying.

FLOWCHART DRAWING With the commands learned thus far, you can create the following easily: USE: GRID 10 SNAP 10 LINE CIRCLE ELLIPSE POLYGON ARC MTEXT DDEDIT DRAW ONE COLUMN & USE COPY STR HYD GEO ENV CIVIL