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” settingsRight 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:

1. Draw a rectangle

2. Turn OSNAP on – Settings – MID (midpoint)

3. 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 a

b

b

Edge start point

Edge end point

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)

Exercise:

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

EndStart

StartCenter

Angle = 75

Start Center

End

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

USE:GRID 10SNAP 10LINECIRCLEELLIPSEPOLYGONARCMTEXTDDEDIT

DRAW ONE COLUMN & USE COPY

STR HYD GEO ENV

CIVIL

With the commands learned thus far, you can create the following easily: