ME2155 COMPUTER AIDED DRAFTING AND MODELING LABORATORY

2D COMMANDS

Ex.No:                                                                                                           Date:

Aim:

            Study of capabilities of software for drafting and modeling co ordinate system

Commands and functions:

Sl. No	Commands	Functions
1.	ARC	Creates an arc
2.	ARRAY	Creates multiple copies of objects in a pattern
3.	BHATCH	Fills an enclosed area or selected objects with a hatch pattern or gradient fill
4.	BLOCK	Creates a block definition from objects you select
5.	BREAK	Breaks the selected object between two points
6.	CHAMFER	Bevels the edges of objects
7.	CIRCLE	Creates a circle
8.	CLOSE	Closes the current drawing
9.	COPY	Copies objects a specified distance in a specified direction
10.	DIMSTYLE	Creates and modifies dimension styles
11.	DONUT	Draws filled circles and rings
12.	ELLIPSE	Creates an ellipse or an elliptical arc
13.	ERASE	Removes objects from a drawing
14.	EXPLODE	Breaks a compound object into its component objects
15.	EXPORT	Saves objects to other file formats
16.	EXTEND	Extends an object to meet another object
17.	FILLET	Rounds and fillets the edges of objects
18.	FIND	Finds, replaces, selects, or zooms to specified text
19.	GRID	Displays a grid in the current viewport that is not plotted
20.	HATCH	Fills an enclosed area or selected objects with a hatch pattern, solid fill, or gradient fill
21.	HELP	Displays Help
22.	HIDE	Regenerates a three-dimensional wireframe model with hidden lines suppressed
23.	IMPORT	Imports files in various formats
24.	ISOPLANE	Specifies the current isometric plane
25.	JOIN	Joins objects to form a single, unbroken object
26.	LAYER	Manages layers and layer properties
27.	LEADER	Creates a line that connects annotation to a feature
28.	LENGTHEN	Changes the length of objects and the included angle of arcs
29.	LIMITS	Sets and controls the limits of the grid display in the current Model or layout tab
30.	LINE	Creates straight line segments
31.	LINETYPE	Loads, sets, and modifies linetypes
32.	LWEIGHT	Sets the current lineweight, lineweight display options, and lineweight units
33.	MENU	Loads a customization file
34.	MIRROR	Creates a mirror image copy of objects
35.	MLINE	Creates multiple parallel lines
36.	MOVE	Moves objects a specified distance in a specified direction
37.	MTEXT	Creates paragraphs of text as a single multiline text (mtext) object
38.	NEW	Creates a new drawing
39.	OFFSET	Creates concentric circles, parallel lines, and parallel curves
40.	OOPS	Restores erased objects
41.	OPEN	Opens an existing drawing file
42.	ORTHO	Constrains cursor movement to the horizontal or vertical direction
43.	OSNAP	Sets running object snap modes
44.	PAN	Moves the view in the current viewport
45.	POINT	Creates a point object
46.	POLYGON	Creates an equilateral closed polyline
47.	QUIT	Exits the program
48.	RECTANG	Draws a rectangular polyline
49.	REDO	Reverses the effects of previous UNDO or U command
50.	REDRAW	Refreshes the display in the current viewport
51.	REGEN	Regenerates the entire drawing from the current viewport
52.	REGION	Converts an object that encloses an area into a region object
53.	ROTATE	Revolves objects around a base point
54.	SAVE	Saves the drawing under the current file name or a specified name
55.	SAVEAS	Saves a copy of the current drawing under a new file name
56.	SPLINE	Fits a smooth curve to a sequence of points within a specified tolerance
57.	SUBTRACT	Combines selected regions or solids by subtraction
58.		TABLE  Creates an empty table object in a drawing
59.	TEXT	Creates a single-line text object
60.	TRIM	Trims objects at a cutting edge defined by other objects
61.	U	Reverses the most recent operation
62.	UCS	Manages user coordinate systems
63.	UCSICON	Controls the visibility and placement of the UCS icon
64.	UNDO	Reverses the effect of commands
65.		UNITS  Controls coordinate and angle display formats and precision
66.	VIEW	Saves and restores named views, camera views, layout views, and preset views
67.	XPLODE	Breaks a compound object into its component objects
68.	ZOOM	Increases or decreases the apparent size of objects in the current viewport

 

 

FUNCTION KEYS

Ex.No:                                                                                                           Date:

Aim:

                       

            To study about FUNCTION KEYS used in AUTOCAD.

Function Keys and functions:

Sl. No	Function Keys	Functions
1.	F1	Displays Help
2.	F2	Toggles Text Window
3.	F3	Toggles OSNAP
4.	F4	Toggles TABMODE
5.	F5	Toggles ISOPLANE
6.	F6	Toggles UCSDETECT
7.	F7	Toggles GRIDMODE
8.	F8	Toggles ORTHOMODE
9.	F9	Toggles SNAPMODE
10.	F10	Toggles Polar Tracking
11.	F11	Toggles Object Snap Tracking
12.	F12	Toggles Dynamic Input

SHORTCUT KEYS

Ex.No:                                                                                                           Date:

Aim:

                       

            To study about SHORTCUT KEYS used in AUTOCAD.

Shortcut Keys  and functions:

Sl. No	Shortcut Keys	Functions
1.	ALT+F11	Displays the Visual Basic Editor
2.	ALT+F8	Displays the Macros dialog box
3.	CTRL+0	Toggles Clean Screen
4.	CTRL+1	Toggles Properties palette
5.	CTRL+2	Toggles DesignCenter
6.	CTRL+3	Toggles the Tool Palettes window
7.	CTRL+4	Toggles Sheet Set Manager
8.	CTRL+6	Toggles dbConnect Manager
9.	CTRL+7	Toggles Markup Set Manager
10.	CTRL+8	Toggles the QuickCalc palette
11.	CTRL+9	Toggles the Command Line window
12.	CTRL+A	Selects all the objects in drawing that are not locked or frozen
13.	CTRL+SHIFT+A	Toggles Groups
14.	CTRL+B	Toggles Snap
15.	CTRL+C	Copies objects to the Windows Clipboard
16.	CTRL+SHIFT+C	Copies objects to the Windows Clipboard with Base Point
17.	CTRL+D	Toggles Dynamic UCS
18.	CTRL+E	Cycles through isometric planes
19.	CTRL+F	Toggles running object snaps
20.	CTRL+G	Toggles Grid
21.	CTRL+H	Toggles PICKSTYLE
22.	CTRL+SHIFT+H	Toggles the display of palettes with HIDEPALETTES and SHOWPALETTES
23.	CTRL+I	Toggles the Coordinates display
24.	CTRL+J	Repeats last command
25.	CTRL+K	Inserts a hyperlink
26.	CTRL+L	Toggles Ortho mode
27.	CTRL+M	Repeats last command
28.	CTRL+N	Creates a new drawing
29.	CTRL+O	Opens an existing drawing
30.	CTRL+P	Plots the current drawing
31.	CTRL+SHIFT+P	Toggles the Quick Properties interface
32.	CTRL+Q	Quits AutoCAD
33.	CTRL+R	Cycles through the viewports on the current layout
34.	CTRL+S	Saves current drawing
35.	CTRL+SHIFT+S	Displays up the Save As dialog box
36.	CTRL+T	Toggles Tablet mode
37.	CTRL+V	Pastes data from the Windows Clipboard
38.	CTRL+SHIFT+V	Pastes data from the Windows Clipboard as a Block
39.	CTRL+X	Cuts objects from the current drawing to the Windows Clipboard
40.	CTRL+Y	Cancels the preceding Undo action
41.	CTRL+Z	Reverses the last action
42.	CTRL+[	Cancels current command
43.	CTRL+\	Cancels current command
44.	CTRL+PAGE UP	Moves to the next layout tab to the left of the current tab
45.	CTRL+PAGE DOWN	Moves to the next layout tab to the right of the current tab

3D COMMANDS

           

Ex.No:                                                                                                           Date:

Aim:

                        To study about AUTOCAD 3D commands.

Commands and functions:

COMMANDS	FUNCTIONS
3D	Creates three-dimensional polygon mesh objects in common geometric shapes that can be hidden, shaded, or rendered
3DALIGN	Aligns objects with other objects in 2D and 3D
3DARRAY	Creates a three-dimensional array
3DCLIP	Starts an interactive 3D view and opens the Adjust Clipping Planes window
3DCONFIG	Provides 3D graphics system configuration settings
3DCORBIT	Starts an interactive 3D view and sets the objects into continuous motion
3DDISTANCE	Starts the interactive 3D view and makes objects appear closer or farther away
3DDWF	Creates a 3D DWF file of your three-dimensional model and displays it in the DWF Viewer
3DFACE	Creates a three-sided or four-sided surface anywhere in 3D space
3DFLY	Interactively changes your view of 3D drawings so that you appear to be flying through the model
3DFORBIT	Controls the interactive viewing of objects in 3D, using an unconstrained orbit
3DMESH	Creates a free-form polygon mesh
3DMOVE	Displays the move grip tool in a 3D view and moves objects a specified distance in a specified direction
3DORBIT	Controls the interactive viewing of objects in 3D
3DORBITCTR	Sets the center of rotation in 3D Orbit view
3DPAN	When a drawing is in a Perspective view, starts the interactive 3D view and enables you to drag the view horizontally and vertically
3DPOLY	Creates a polyline of line segments in 3D space
3DROTATE	Displays the rotate grip tool in a 3D view and revolves objects around a base point
3DSIN	Imports a 3D Studio (3DS) file
3DSWIVEL	Changes the target of the view in the direction that you drag
3DWALK	Interactively changes the view of a 3D drawing so that you appear to be walking through the model
3DZOOM	Zooms in and out in a perspective view

POLYGONS

Ex. No. :                                                                                                                      Date:

Question:

            Draw the following polygons using co-ordinate system. Draw according to the dimensions and also mark the dimensions.

i.                    Equilateral triangle of side 50 mm

ii.                  Square of side 50 mm

iii.                Pentagon of side 50 mm

iv.                Hexagon of side 50 mm

v.                  Octagon of side 50 mm

Aim:

To draw the following polygons using co-ordinate system

i.                    Equilateral triangle of side 50 mm

ii.                  Square of side 50 mm

iii.                Pentagon of side 50 mm

iv.                Hexagon of side 50 mm

v.                  Octagon of side 50 mm

System configuration:

o   Pentium IV computer or better hardware, 512 MB RAM, 14 inch Colour monitor with suitable graphics facility 

o   Laser Printer or Plotter to print / plot drawings

Software used:

            Licensed software for Drafting and Modeling - AutoCAD 2000 series

Commands used:

o   Starting commands:

§  Limits, Zoom all, ltscale, dimscale, dimstyle.

o   Drawing commands:

§  Line, rectangle, circle, polygon, multiline text.

o   Edit commands:

§  Erase, move, copy, trim, extend, chamfer, fillet.

o   Dimensioning commands:

§  Dimlinear, Dimalligned, Dimradius, Dimdiameter.

Procedure:

1.      Open the AutoCAD software and set the starting commands.

2.      Size of the page is set according to the drawing size by using LIMITS command and ZOOM on to generate.

3.      By clicking the line command to draw required lines by giving measurement in command

4. Polygon command is used to create an equilateral closed poly line.

5.      Unwanted extensions are erased by TRIM command.

6.      MOVE command is used to Move the objects a specified distance in a specified direction

7.      ERASE command is used to erase unwanted objects in the diagram.

8.      Click on dimension , select linear to give measurement to the required lines and press enter.

9.      Save the drawing.

10.  Check all and take the print out.

Result:

            Thus the given polygons are drawn as per the given dimension using using the software AutoCAD.

INVOLUTES

Ex. No. :                                                                                                                      Date:

Question:

       

        Draw an INVOLUTE of the following polygons.

                                                              i.      Equilateral triangle of side 50 mm

                                                            ii.      Square of side 40 mm

                                                          iii.      Pentagon of side 40 mm

                                                          iv.      Hexagon of side 30 mm

Aim:

To construct the INVOLUTE of the following polygons using AutoCAD

                                                              i.      Equilateral triangle of side 50 mm

                                                            ii.      Square of side 40 mm

                                                          iii.      Pentagon of side 40 mm

                                                          iv.      Hexagon of side 30 mm

System configuration:

o   Pentium IV computer or better hardware, 512 MB RAM, 14 inch Colour monitor with suitable graphics facility 

o   Laser Printer or Plotter to print / plot drawings

Commands used:

o   Starting commands:

§  Limits, Zoom all, ltscale, dimscale, dimstyle.

o   Drawing commands:

§  Line, rectangle, circle, polygon, multiline text.

o   Edit commands:

§  Erase, move, copy, trim, extend, chamfer, fillet.

o   Dimensioning commands:

§  Dimlinear, Dimalligned, Dimradius, Dimdiameter.

Software used:

           

            Licensed software for Drafting and Modeling - AutoCAD 2000 series

Procedure:

1.      Open the AutoCAD software and set the starting commands.

2.      Size of the page is set according to the drawing size by using LIMITS command and ZOOM on to generate.

3.      By clicking the line command to draw required lines by giving measurement in command

4.      Polygon command is used to create an equilateral closed poly line.

5.      CIRCLE command is used to draw a circle.

6.      Unwanted extensions are erased by TRIM command.

7.      MOVE command is used to Move the objects a specified distance in a specified direction

8.      ERASE command is used to erase unwanted objects in the diagram.

9.      Click on dimension , select linear to give measurement to the required lines and press enter.

10.  Save the drawing.

11.  Check all and take the print out.

Result:

Thus the INVOLUTE of the given polygons were drawn using AutoCAD.

STANDARD TITLE BLOCK IN A3 SIZE SHEET

Aim:

            To draw the standard title block in A3 size sheet using Auto CAD commands.

System configuration:

o   Pentium IV computer or better hardware, 512 MB RAM, 14 inch Colour monitor with suitable graphics facility 

o   Laser Printer or Plotter to print / plot drawings

Software used:

            Licensed software for Drafting and Modeling - AutoCAD 2000 series

Commands used:

o   Starting commands:

§  Limits, Zoom all, ltscale, dimscale, dimstyle.

o   Drawing commands:

§  Line, rectangle, circle, polygon, multiline text.

o   Edit commands:

§  Erase, move, copy, trim, extend, chamfer, fillet.

o   Dimensioning commands:

§  Dimlinear, Dimalligned, Dimradius, Dimdiameter.

Procedure:

1.         Open the AutoCAD software and set the starting commands.

2.         Size of the page is set according to the drawing size by using LIMITS command and ZOOM on to generate.

3.         By clicking the line command to draw required lines by giving measurement in command

4.         Polygon command is used to create an equilateral closed poly line.

5.         Unwanted extensions are erased by TRIM command.

6.         MOVE command is used to Move the objects a specified distance in a specified direction

7.         ERASE command is used to erase unwanted objects in the diagram.

8.         Click on dimension , select linear to give measurement to the required lines and press enter.

9.         Save the drawing.

10.     Check all and take the print out.

Result:

           

            Thus the title block is drawn in A3 size sheet by using Auto CAD commands.

SIMPLE DIAGRAM USING ABSOLUTE, RELATIVE, POLAR CO-ORDINATE SYSTEM

AIM:

            To draw the given  simple diagram using absolute, relative, polar co-ordinate system.

System configuration:

o   Pentium IV computer or better hardware, 512 MB RAM, 14 inch Colour monitor with suitable graphics facility 

o   Laser Printer or Plotter to print / plot drawings

Software used:

            Licensed software for Drafting and Modeling - AutoCAD 2000 series

Commands used:

o   Starting commands:

§  Limits, Zoom all, ltscale, dimscale, dimstyle.

o   Drawing commands:

§  Line, rectangle, circle, polygon, multiline text.

o   Edit commands:

§  Erase, move, copy, trim, extend, chamfer, fillet.

o   Dimensioning commands:

§  Dimlinear, Dimalligned, Dimradius, Dimdiameter.

Procedure:

1.         Open the AutoCAD software and set the starting commands.

2.         Size of the page is set according to the drawing size by using LIMITS command and ZOOM on to generate.

3.         By clicking the line command to draw required lines by giving measurement in command

4.         Polygon command is used to create an equilateral closed poly line.

5.         Unwanted extensions are erased by TRIM command.

6.         MOVE command is used to Move the objects a specified distance in a specified direction

7.         ERASE command is used to erase unwanted objects in the diagram.

8.         Click on dimension , select linear to give measurement to the required lines and press enter.

9.         Save the drawing.

10.     Check all and take the print out.

Result:

           

            Thus the given simple diagram is drawn in Auto CAD by using the absolute, relative, polar co-ordinate system.

PENTAGONAL PRISM RESTING ON HP

Question:

            Draw the front view and top view of a pentagonal prism of base side 50 mm and axis length 100 mm resting on HP on one of its bases when

                                                        i.            One of the base edges is perpendicular to VP.

                                                      ii.            One of the base edges is parallel to VP and nearer to it.

                                                    iii.            One of the base edges is inclined 45⁰ to VP.

                                                    iv.            Two adjacent base edges are equally inclined to VP.

Aim:

            To draw the orthographic views of a pentagonal prism resting on HP using Auto CAD commands.

System configuration:

o   Pentium IV computer or better hardware, 512 MB RAM, 14 inch Colour monitor with suitable graphics facility 

o   Laser Printer or Plotter to print / plot drawings

Software used:

            Licensed software for Drafting and Modeling - AutoCAD 2000 series

Commands used:

o   Starting commands:

§  Limits, Zoom all, ltscale, dimscale, dimstyle.

o   Drawing commands:

§  Line, rectangle, circle, polygon, multiline text.

o   Edit commands:

§  Erase, move, copy, trim, extend, chamfer, fillet.

o   Dimensioning commands:

§  Dimlinear, Dimalligned, Dimradius, Dimdiameter.

Procedure:

11.     Open the AutoCAD software and set the starting commands.

12.     Size of the page is set according to the drawing size by using LIMITS command and ZOOM on to generate.

13.     By clicking the line command to draw required lines by giving measurement in command

14.     Polygon command is used to create an equilateral closed poly line.

15.    Unwanted extensions are erased by TRIM command.

16.     MOVE command is used to Move the objects a specified distance in a specified direction

17.     ERASE command is used to erase unwanted objects in the diagram.

18.     Click on dimension , select linear to give measurement to the required lines and press enter.

19.     Save the drawing.

20.     Check all and take the print out.

Result:

            Thus the orthographic views of a pentagonal prism resting on HP is drawn by using Auto CAD commands.

PENTAGONAL PYRAMID RESTING ON HP

Question:

            Draw the front view and top view of a pentagonal pyramid of base side 50 mm and axis length 100 mm resting on HP on one of its bases when

                                                      v.            One of the base edges is perpendicular to VP.

                                                    vi.            One of the base edges is parallel to VP and nearer to it.

                                                  vii.            One of the base edges is inclined 45⁰ to VP.

                                                viii.            Two adjacent base edges are equally inclined to VP.

Aim:

            To draw the orthographic views of a pentagonal pyramid resting on HP using Auto CAD commands.

System configuration:

o   Pentium IV computer or better hardware, 512 MB RAM, 14 inch Colour monitor with suitable graphics facility 

o   Laser Printer or Plotter to print / plot drawings

Software used:

            Licensed software for Drafting and Modeling - AutoCAD 2000 series

Commands used:

o   Starting commands:

§  Limits, Zoom all, ltscale, dimscale, dimstyle.

o   Drawing commands:

§  Line, rectangle, circle, polygon, multiline text.

o   Edit commands:

§  Erase, move, copy, trim, extend, chamfer, fillet.

o   Dimensioning commands:

§  Dimlinear, Dimalligned, Dimradius, Dimdiameter.

Procedure:

21.     Open the AutoCAD software and set the starting commands.

22.     Size of the page is set according to the drawing size by using LIMITS command and ZOOM on to generate.

23.     By clicking the line command to draw required lines by giving measurement in command

24.     Polygon command is used to create an equilateral closed poly line.

25.    Unwanted extensions are erased by TRIM command.

26.     MOVE command is used to Move the objects a specified distance in a specified direction

27.     ERASE command is used to erase unwanted objects in the diagram.

28.     Click on dimension , select linear to give measurement to the required lines and press enter.

29.     Save the drawing.

30.     Check all and take the print out.

Result:

            Thus the orthographic views of a pentagonal pyramid resting on HP is drawn by using Auto CAD commands.

ORTHOGRAPHIC VIEWS OF CONE AND PYRAMID

AIM:

            To draw the orthographic views of cone and pyramid using Auto CAD commands.

Procedure:

1.      Open the Auto CAD software and set the starting commands.

2.      Draw the title block in A3 size templates.

3.      Draw the front view and top view of the cone and pyramid using draw commands and modify commands.

4.      Set the dimension style and give the dimension using dimension commands.

5.      Check all the diagrams and take print out.

Commands used:

1. Starting commands:

            Limits, Zoom all, ltscale, dimscale, dimstyle.

2. Drawing commands:

            Line, rectangle, circle, polygon, multiline text.

3. Edit commands:

            Erase, move, copy, trim, extend, chamfer, fillet.

4. Dimensioning commands:

            Dimlinear, Dimalligned, Dimradius, Dimdiameter.

Result:

            Thus the orthographic views of cone and pyramid is drawn by using Auto CAD commands.

PARABOLA, SPIRAL AND INVOLUTE CURVES

AIM:

            To draw the parabola, spiral and involute curves using B-spline or cubic spline in Auto CAD commands.

Procedure:

1.      Open the Auto CAD software and set the starting commands.

2.      Draw the title block in A3 size templates.

3.      Draw the parabola, spiral and involute curves using B-spline or cubic spline.

4.      Set the dimension style and give the dimension using dimension commands.

5.      Check all the diagrams and take print out.

Commands used:

1. Starting commands:

            Limits, Zoom all, ltscale, dimscale, dimstyle.

2. Drawing commands:

            Line, rectangle, circle, polygon, multiline text.

3. Edit commands:

            Erase, move, copy, trim, extend, chamfer, fillet.

4. Dimensioning commands:

            Dimlinear, Dimalligned, Dimradius, Dimdiameter.

Result:

            Thus the parabola, spiral and involute curves using B-spline or cubic spline is drawn by using Auto CAD commands.

ORTHOGRAPHIC VIEWS OF MIXIE BASE AND OPEN BEARING

AIM:

            To draw the orthographic views of mixie base and open bearing using Auto CAD commands.

Procedure:

1.      Open the Auto CAD software and set the starting commands.

2.      Draw the title block in A3 size templates.

3.      Draw the front view and top view of the mixie base and open bearing using draw commands and modify commands.

4.      Set the dimension style and give the dimension using dimension commands.

5.      Check all the diagrams and take print out.

Commands used:

1. Starting commands:

            Limits, Zoom all, ltscale, dimscale, dimstyle.

2. Drawing commands:

            Line, rectangle, circle, polygon, multiline text.

3. Edit commands:

            Erase, move, copy, trim, extend, chamfer, fillet.

4. Dimensioning commands:

            Dimlinear, Dimalligned, Dimradius, Dimdiameter.

Result:

            Thus the orthographic views of mixie base and open bearing is drawn by using Auto CAD commands.

ORTHOGRAPHIC VIEWS OF TOOL POST AND V BLOCK

AIM:

            To draw the orthographic views of tool post and V block using Auto CAD commands.

Procedure:

1.      Open the Auto CAD software and set the starting commands.

2.      Draw the title block in A3 size templates.

3.      Draw the front view and top view of the tool post and V block using draw commands and modify commands.

4.      Set the dimension style and give the dimension using dimension commands.

5.      Check all the diagrams and take print out.

Commands used:

1. Starting commands:

            Limits, Zoom all, ltscale, dimscale, dimstyle.

2. Drawing commands:

            Line, rectangle, circle, polygon, multiline text.

3. Edit commands:

            Erase, move, copy, trim, extend, chamfer, fillet.

4. Dimensioning commands:

            Dimlinear, Dimalligned, Dimradius, Dimdiameter.

Result:

            Thus the orthographic views of tool post and V block is drawn by using Auto CAD commands.

SECTIONAL VIEWS OF CYLINDER AND PRISMS

AIM:

            To draw the sectional views of cylinder and prisms using Auto CAD commands.

Procedure:

1.      Open the Auto CAD software and set the starting commands.

2.      Draw the title block in A3 size templates.

3.      Draw the sectional views of cylinder and prisms using draw commands and modify commands.

4.      Set the dimension style and give the dimension using dimension commands.

5.      Check all the diagrams and take print out.

Commands used:

1. Starting commands:

            Limits, Zoom all, ltscale, dimscale, dimstyle.

2. Drawing commands:

            Line, rectangle, circle, polygon, multiline text.

3. Edit commands:

            Erase, move, copy, trim, extend, chamfer, fillet.

4. Dimensioning commands:

            Dimlinear, Dimalligned, Dimradius, Dimdiameter.

Result:

            Thus the sectional views of cylinder and prisms is drawn by using Auto CAD commands.

SECTIONAL VIEWS OF CONE AND PYRAMIDS

AIM:

            To draw the sectional views of cone and pyramids using Auto CAD commands.

Procedure:

1.      Open the Auto CAD software and set the starting commands.

2.      Draw the title block in A3 size templates.

3.      Draw the sectional views of cone and pyramids using draw commands and modify commands.

4.      Set the dimension style and give the dimension using dimension commands.

5.      Check all the diagrams and take print out.

Commands used:

1. Starting commands:

            Limits, Zoom all, ltscale, dimscale, dimstyle.

2. Drawing commands:

            Line, rectangle, circle, polygon, multiline text.

3. Edit commands:

            Erase, move, copy, trim, extend, chamfer, fillet.

4. Dimensioning commands:

            Dimlinear, Dimalligned, Dimradius, Dimdiameter.

Result:

            Thus the sectional views of cone and pyramid is drawn by using Auto CAD commands.

ISOMETRIC PROJECTION OF MACHINE BLOCK, CI CASTING AND ROD SUPPORT

AIM:

            To draw the isometric projection of machine block, CI casting and rod support using Auto CAD commands.

Procedure:

1.      Open the Auto CAD software and set the starting commands.

2.      Draw the title block in A3 size templates.

3.      Set the GRID style in Isometric option.

4.      Set ORTHO mode on.

5.      Draw the left, right and top phase diagram in left plane, right plane and top plane respectively.

6.      Give the dimension using aligned option then oblique the dimension with respect to the plane axes.

7.      Check all the diagrams and take print out.

Commands used:

1. Starting commands:

            Limits, Zoom all, ltscale, dimscale, dimstyle.

2. Drawing commands:

            Line, rectangle, circle, polygon, multiline text.

3. Edit commands:

            Erase, move, copy, trim, extend, chamfer, fillet.

4. Dimensioning commands:

            Dimlinear, Dimalligned, Dimradius, Dimdiameter.

Result:

            Thus the isometric projection of machine block, CI casting and rod support is drawn by using Auto CAD commands.

3D MODEL OF ROD SUPPORT AND OBTAINING MULTIVIEW DRAWINGS

AIM:

            To draw the 3d model of rod support and obtaining multi view drawings

Using Auto CAD commands.

Procedure:

1.      Open the Auto CAD software and set the starting commands.

2.      Draw the title block in A3 size templates.

3.      Set the view-3d view-sw isometric view.

4.      Draw the top view and give extrude, subtract and intersect commands to build the model.

5.      Give the dimension using aligned option.

6.      Check all the diagrams and take print out.

Commands used:

1. Starting commands:

            Limits, Zoom all, ltscale, dimscale, dimstyle.

2. Drawing commands:

            Line, rectangle, circle, polygon, multiline text.

3. Edit commands:

            Erase, move, copy, trim, extend, chamfer, fillet.

4. Dimensioning commands:

            Dimlinear, Dimalligned, Dimradius, Dimdiameter.

Result:

            Thus the 3d model of rod support and obtaining multi view drawings are obtained from 3D model by using Auto CAD commands.

PLAN OF RESIDENTIAL BUILDING

AIM:

            To draw the plan of residential building by using Auto CAD commands.

Procedure:

1.      Open the Auto CAD software and set the starting commands.

2.      Draw the title block in A3 size templates.

3.      Draw the plan of residential building using draw commands and modify commands.

4.      Set the dimension style and give the dimension using dimension commands.

5.      Check all the diagrams and take print out.

Commands used:

1. Starting commands:

            Limits, Zoom all, ltscale, dimscale, dimstyle.

2. Drawing commands:

            Line, rectangle, circle, polygon, multiline text.

3. Edit commands:

            Erase, move, copy, trim, extend, chamfer, fillet.

4. Dimensioning commands:

            Dimlinear, Dimalligned, Dimradius, Dimdiameter.

Result:

            Thus the plan of residential building is drawn by using Auto CAD commands.

SIMPLE STEEL TRUSS

AIM:

            To draw the simple steel truss by using Auto CAD commands.

Procedure:

1.      Open the Auto CAD software and set the starting commands.

2.      Draw the title block in A3 size templates.

3.      Draw the simple steel truss using draw commands and modify commands.

4.      Set the dimension style and give the dimension using dimension commands.

5.      Check all the diagrams and take print out.

Commands used:

1. Starting commands:

            Limits, Zoom all, ltscale, dimscale, dimstyle.

2. Drawing commands:

            Line, rectangle, circle, polygon, multiline text.

3. Edit commands:

            Erase, move, copy, trim, extend, chamfer, fillet.

4. Dimensioning commands:

            Dimlinear, Dimalligned, Dimradius, Dimdiameter.

Result:

            Thus the simple steel truss is drawn by using Auto CAD commands.

           

VIVA VOCE QUESTIONS & ANSWERS

1.      Define the following terms?

3D face: A triangular or four-sided flat surface that is the basic unit of a 3D surface.

 3D mesh: A set of adjacent flat surfaces that together form a geometrical depiction of a three dimensional curved surface.

3D model: An AutoCAD drawing file containing AutoCAD objects that occupy 3D space and represent building components or geometrical objects in the n See also object.

3ds Max: A complementary product to AutoCAD, also produced by j With 3ds Max you can create and animate 3D scenes.

2.      What is absolute coordinates?

Values for locating a point in space that describe its displacement from t (0, 0, 0) point of the drawing.

3.      Define alias.

A shortcut for starting commands. It's a short string of characters that enter at the command line instead of the full command.

4.         Define aligned dimension

A linear dimension measuring the distance between two points. The dime for an aligned dimension is parallel to a line between the two points.

5.         Define angular dimension

A dimension that measures the angle between two lines or the angle ins an arc segment.

6.         What is Angular unit?

The unit in which angle values are displayed. The choices are Decimal Degrees-Minutes-Seconds (listed as Deg/Min/Sec), Grads, Radians, and S Units.

7.         Define associative dimension.

A dimension that updates automatically when the object being dimensione size.

12.       Define The description of an. association of AutoCAD objects that is stored \vith the drm.ving file and incllj.d.eSllname, an insertion point, and a listing of objects in the association.

13.       Wfiat is block reference'?

An' instance of a grouping of objects that is inserted into a drawing and is based all the block definition for that grouping. Casually called a block,

15 What is Boolean operation?

A series of tools that, when used with two overlapping 3D objects, result in either the two objects being joined as one (Union), one object and the overlapping volume being deleted (Subtract), or the parts of both objects outside the overlapping volume

            are deleted (Intersect).            .

16.       Define Box

A 3D object consisting of a rectangular base and cap and four rectangular sides.

17.       What is ByLayer?

A value that can be assigned to colors and linet'jpes so that objects receive their color and linetype properti~ according to the layer they are on.

19 Define Cartesian coordinate system

A 2D system of locating 'points on a plane. It uses a horizontal (X) component and a vertical (Y) component to locate a point relative tothe 0,0 point, or origin.

20.       What is cOmllland line?

A text window at the boltom of the screen that displays COll1.'Tland: prompts. This is where you see what yOu're entering through the keyboard. Also called the Command- window.

21.       What is Command: prompt :

The prompt at tIle command line, when no commands are currently running.

22.       What is c()llle'Xtmcnu--?

A menu that~~~~~S()ll_the drawing area usually as the resultof a right-c1ick¬and contains options relevant to what the user is doing at that moment. Also called a shortcut me

Define continued dimension

A dimensioning option that allows you to pJace sequential dimensions adjacent to each other so that the dimension Jines are aligned.

What is crosshair cursor'!

A form of the cursor that consists of a horizontal line and a vertical line intersecting at their midpoints, resembling the crosshairs in a sighting device.

The user coordinate system (UCS) that is active in a drawing. It determines th~ positive X, Y, and Z directions.

Define Dashboard

A specialized palette that houses tools and controls for easy access, It's subdivided into one to sixteen control panels.

A measurement, usually of distance or angu~arity, relating to features in the drawing. Define dimension style

A coilection of settings for dimensIon variables that is saved in a drawing under a specifieclname. Dimensions placed in the drawing follow the settings of the current diInension

The text in a dimension. It expresses the measurement displaying or textual information at the end of a leader.

Define dimension variables. -

A group of settings and values that control the appearance of dimensions. What is display locking?

The practice of setting a floating vieHpOl1 so that, when it is active, the scale factor does not change.

38.       What is docking?

Relocating a toolbar or a palette to the perimeter of the drawing area so it won't interfere with the AutoCAD drawing or other items on the screen.

39.       What is drawing area?

The portion of the monitor screen where you draw objects and view your drawing.

40.       What is drawing exients?

The minimum rectangular area with the same proportions as your drawing area that will enclose nonfrozen objects in your drawing. 'When you use the Zoom Extents command, the rectangular area fills the drawing area.

Define grid.

2. A series of horizontal and vertical lines in a floor plan or section that locate the main structural elements of a building, such as columns and walls. This type is also called a column grid or a structural grid.

What is an hatch patterns?

A pattern of Jines, dots, and other shapes that fills in a closed area. Define an insertion point.

A reference point that is part of a block and is used to locate the block when it's inserted into a drawing. It's attached to the cursor while a block IS being inserted. Once a block has been inserted, use the Insertion osnap to snap to the insertion point of the block.

Define Isometric view

A pictorial view of a 3D object in which all lines that are parallel on the object appear parallel in the view.

What is jamb?

A surface that forms the side or top of an opening for a cloor or window in a wall. What is justification point?

A reference point on a line of single-line text or a body of multiline text that like the insertion point for blocks.

Define layer

An organizing tool that operates like an electronic version of transparent overlays on a drawing board. Layers can be assigned color and a linetype, and their visibility can be controlled. All objects in an AutoCAD drawing are assigned to a layer.

Derme layout

An optional interface that serves as an aid to the user in setting up a drawing for printing. It rests "on top of" the model space in which the drawing of the bUilding resides. It usually contains the title block, notes, scale, and other infonnation. User view a drawing through openings in the layout called floating viewpons. A singl drawing file can have multiple layouts, one for each print to be made from th file. The layout interface is sometimes referred to as paper space.

Derme linetype. The style of appearance of a line. AutoCAD styles include continuous, dash-dot, and so on.

Define lineweight. The value of a line's width measured in inches or millimeters. Define Mirror. A command that makes a copy of selected objects and flips the copy around specified line to produce a reciprocal image of those objects.

A view of your drawing that is saved and given a name so that it can be restored ,i

            later.    :1

            Define an object.         il

A basic AutaCAD graphical element that is created and manipulated as part of the II

drawing, such as a line, an are, a dimension, a block, or text. Also called an entity. II

83.       What is an Object Snap mode?           ,I

Any of a set of tools for precisely picking strategic poinrs on an (jl~iecr, including :1

            Endpoint, Midpoint, Center, and so on. It's casually called osnap.   ii'

            What is an oril:dn'?                 I

            The p,aint with ~~e coordinates                     il

            What is an Ortho mode?         0,0,0, where the X-, y-. and z-axes meet,

A C01l1illRHC1 that slides the current dra\ving around on the dra\ving area \vithuut 11

II

            changing the magnification of the view.        "

            Define paper space      :1

A term sometimes used to ret'h 10 the interface for a drawing that contains layoms. Ii What is Perspective view'? i,'l' A pictorial view of a 3D object in which p, arallel lines that aren't parallel La the

!i plane of the screen appear to converge as they move farther from the viewer. similar 'I

1',,'1

to the way objects appear in the rea] wOTld (such as railroadtracks in tbe distance)

What is pick button? II

:1

The button on the mouse (usually the left one) that is used to pick points, buttons, :i

            or menu items, as well as to select objects in the drawing area.         il

            What is pickbox?

An on/off setting that, when on, forces lines to be drawn and objects to be moved in a horizontal or vertical direction only.

A system or creating views in which each view shO\vs a different side of a bllllding or an object, such as the top, from, left side, right side, and so OIL

A form of the cursor as a small square that occurs \vhen AutoCAD is in selection mode.

A view of a drawing in which the viewer is looking straight at the XY plane in

What is Plan view?

94.       What is plot style?

A group of settings assigned to a layer , a color, or an object. determine how that layer, color, or object is printed.

97.       DermePolat coordiri.ates.

Values forlocating'apoint• in space that describe itS locationre point picked as defined by an angle and a diStance.

99.       Derme polyline.

A special rype oHinetImt (a) treats multiple segments as one obje¢t; arcs, (c) can be smoothed into a curved line, and (d) can h applications.

102.     Define Redra.w A command to refresh the drawing area or a particular viewPQ it of any graphic distortions that show upon the monitor whil

10J.Define regeneration.

A process in . which the geometry for the objects in the current . recalculated.

105.     Define relative coordinates

Values for locating a point in space that describe its displacel1le,n, point picked in the drawing rather than from the origin.

106.     Define render.

The practice of calculating the ~,L~}CeS, lights, materials, andenvir

an image file. The command_ to do so is alsQcalled Render.

107.     What is rubberbanding?

The effect of a line extending between the last point picked and stretching like a rubber band as the cursor is moved.

,

109.     What isscalefa.ctor?

The number that expresses the true ratio of a scale. For example,•4 factor for quarter-inch scale (ID 4" = 1'-0").

112.     What is selection set?

Any object or group of objects. that have been selected for modifica been selected to be used in a modification process.

113.     Derme selection window

A tool for selecting objects whereby the user creates a rectangular win drawingarea. Objects are selected in two ways, depending on whether th windoW iSactossing window or a regular window.

117.     Derme soffit

The underside of the roof overhang that extends from the outside edge back to the wall.

1.        

2.         The

3.         A threedim a solid block of

4.         Define stud

pattern that fills a defmed boundary with a solid color. j;)bject in AutoCAD that has properties similartQ those of erial, such as mass, center of gravity, density, and so. on.

5.        

A verticaLpie~~pflumber or metal used in framing walls. It's usually 2" x 4" or 2" Xi 6"in cross dimension and extends the height of the wall.

120.     What is SllrY~YOr's Units?

An angular unit of direction in which the value is the angle that the direction devia,tes away (or bears)from true north or south, toward the east or west.

121.     Derme table.'

A matrix of information such as a spreadsheet, usually included in construction drawings, '. tht\tcontains data presented in rows and columns separated by lines.

122.     Derme template'drawing

A draWing t1jathasbeen set up to serve as a format for anew drawing. This allows the user to.begiiIanew drawing with certain parameters already set up, because various settings/have been predetermined.

123.     What istext"'$tyle?

A collectionq:l?c'$c:ttingsthatcontrols the appearance of text and is saved in a drawing under asp~jfi~qpl;ll)lY.Text placed in the drawing will follow the settings of the current text/§.tYle:

124.     Def'm~ a The onp on layer during a

125.     What is

Thedi in whic

a buildin

See also

,

a setting called Freeze/Thaw that controls the visibility of objects 'ines whetherAutoCAD calculates the geometry of these objects n.

~Qbjectisex.truded in a direction perpendicular to the. plane lydrawn,.rY~91ting in a 3D object .. For a floor plan of . lIleextruded.•tcfathickness that is the wall's actual height.

126.     Whati

A fea

user setsuptempqrary points or angles as guides for ~ir¢pqintsinthe pracessof drawing. Object snap tJ:W.tell1pOfl:lfY points,. and polar tracking sets the angles.

.           is tracking points'!

The temporary points that are set up for use

129.     What is transparent command?

A command that can be executed while another command is interfering WiLtl fue ruillling command. Display commands, such

. are transparent.

130.     What is true ratio?

An expression of two numbers fuat defInes that• is, the number of units represented by a

132.     Derme user coordinate system (UCS).

A defInition for the orientation of the X-, y-, and z-axes in space relative t objects in the drawing or to the world coordinate system (WeS) named, saved,and restored.

133.     Derme view.• A display of the current drawing is shown on the screen or in a viewport. Views

134.     Define viewport An opening •usually rectangular, but not always--through which the a drawing or a portion of it. There are two kinds of viewports: tiled (used in model space) and floating viewports (~d in layouts).

135.     Define wireframe A view of a 3D object that uses lines to represent fue intersections planes defIned by these lilles represent surfaces of building componentS, parts, and so on.

Define workspace. A customizable arrangement of dockable palettes, menus, and to graphics window that can be named, saved, and made current.

138.     Define world coordinate system (WCS) The default user coordinate system (UeS) for all new drawing fIles, in positive directions for the x- and y-axes are to the right and upward, res and in which the positive direction for the z-axis is toward the user and perpe

to the plane of the screen.

140.     Derme Zoom

The name of a command with several options, all of which allow the user to . or decrease the magnifIcation of the view of the current drawing in the area or in a viewport.

1. What is meant by command ?

The instructions to be input into a drafting software for making a drawing, copying, saving, etc. are called commands.

2. State the different methods of sending in commands.

Command can be typed on the keyboard. It may be picked from a menu or tablet or selected from a bar like standard tool bar and modify tool bar by using a mouse.

3. What is an entity?

A drawing element like line, arc and circle is called an entity.

4. State the different items displayed in a typical user-system graphic int~rface of AutoCAD.

A typical user-system graphic interface consists of menu bar, standard toolbar, draw toolbar, modify toolbar, status bar, vertical scroll bar, horizontal scroll bar, drawing area and command area.

5. Drawing area is a rectangular part of the graphics area of the screen. True / False Ans: True.

6. Command area is generally a three-line area in AutoCAD. True / False Ans: True.

7. What is dialog box?

The user-graphic interface that appears on the screen as response to certain commands is called dialog box. It has check boxes, buttons to click on for alternative options. There are boxes for OK, apply, cancel and so on. Click on OK will return the user to the usual user interface.

8. State the different methods of drawing a line by using AutoCAD.

The different methods of drawing a line are i) absolute co-ordinate system ii) relative rectangular co-ordinate system and iii) relative polar co-ordinate system.

9. Write the sequence to be followed for drawing an equilateral triangle ABC shown in Fig. 1.

Command From point

Line or L

Pick A ..-J (Take the cursor to any pui.:1t on the screen and press the left button).

To point           @ 5, 0 ..-J

To point           @ 5 < 120 ..-J

To point           @ 5 < 240 ..-J

To point           ..-J

Remember that..-J means 'press ENTER key'.

           

10. Write the sequence to be followed for drawing the lines AB, BC and CD shown in Fig. 2.

            Command       Line or L

            From point      Pick A ..-J

To point To point To point To point

@ 4,0 .-J @ 0, 2 .-J

@ 5 < 45 .-J .-J

4

11. How is @ entered?           Aa.2

@ is entered by pressing both shift key and 2 key simultaneously.

12. How will command: prompt be restored if everything got messed up while handling the AutoCAD?

If everything got messed up while replying to prompts or sending in command, just press Ese key available on the keyboard at left, top corner or press Ctrl and C keys. Command: prompt will be restored.

13. Illustrate the method of finding the co-ordinates of the line AB shown in

Fig. 3. B

Command : ID.-J

Point    End .-J of PI .-J

Now, the x and y co-ordinates of A are displayed. Command : ID.-J

Point    End .-J of P2 .-J

Now, the x and y co-ordinates of B are displayed.    A

Note: With Osnap on, the end point command will select the end point of a line nearest to the cursor.

           

16. Name the commands to be used for drawing the diagram shown in Fig. 4. Line command for drawing line. Arc com. mand for drawing the., [QJ

arc. Circle command, for drawing the circle. 0 FigA

17. State the use of CLOSE command.

Close command joins the first point (start point) and the

last point of a series of lines drawn. AB, BC and CD are~. c ~D

t'J.rawn by using line command (Fig.5). When close             L C .

command is issued, the line DA joining the last point with ~                        .

the first point is automatically drawn.            A         B         Flg.5

18. Write the commands for drawing a rectangle, ellipse and polygon. Command for drawing a rectangle is Rectang, ellipse - Ellipse or EL, polygon - Polygon or POL.

19. State the minimum and maximum number of sides of a polygon that can be drawn by using AutoCAD.

In Auto CAD , polygon having a minimum of 3 sides and a maximum of 1 024 sides can be drawn. Here, all the sides are of equal length.

20. Write the command and sequence for drawing a rectangle of sides 5 units and 3 units.

Command       Rectang ..-J

First Corner     2, 2 ..-J

Other corner    7, 5 ..-J

First corner may be any point of any co-ordinates. Increase the x co-ordinate by 5 units and y co-ordinate by 3 units to locate the other corner. A rectangle of sides 5 units and 3 units is drawn.

21. State the different methods of drawing ellipse by using AutoCAD. i) An ellipse of given major axis and minor axis.

ii) An ellipse of given major axis and angle of rotation around major axis. iii) An ellipse of known centre, major axis and minor axis.

22. State the op!t~ns available for drawing a polygon.

i) A polygon of known number of sides given the inscribing/circumscribing circle. ii) A polygon of known number of sides and edge length.

23. What is a polyline in AutoCAD? Write its command.

Polyline represents a group of lines and arcs taken as a single unit. Command for polyline is Pline or PL.

24. What is the speciality oipolyline command? or State when polyline command is used.

Different entities like line, are, chamfers and fillets are taken as a single unit in polyline. Individual segments of polyline can be of single wtdth or varying width forming a closed polygon. The perimeter and area of polyline can be obtained.

25. State the characteristics of a polyline command.

Same as that for Qn.24.

26. What is Osnap? State its uses.

Osnap means 'running object snap. OSNAP, DDOSNAP or OS means the same. OSNAP command is used to place a snap point at an exact location of an object line like the end point of a line, intersection of two lines, mid-point of a line and centre of circle.

27. State the uses of grid command and snap command. Grid command is used to display a grid of dots of desired spacing.

Snap command is used to control the movement of cursor at specified intervals. When the snap is on, the cursor moves on an imaginary rectangular grid of specified interval. Normally, snap interval is kept the same as grid spacing.

What are the commands to be used for drawing the diagram shown in Fig. 6"(

            e commands to be used are OSnap, Snap, Ortho and circle.              100

                        o 100 50 I                    Fig.6

. Sub-commands CEN, QUA, MID operate even with Osnap off. True / False ue. But only one such sub-command is operational at a time .

. What are the commands used for drawing isometric views? State the order which they are to be issued.

le commands used for drawing isometric views are i) DDRMODES or RM and ii) OPLANE. RM command is issued first. Isoplane is issued next. Isoplane command Ips in choosing the isometric plane and also the current pair of axes which are required work on .

.. Distinguish between ERASE and UNDO commands.

rase command removes objects from the screen. Undo or U command undoes the last mmand whatever may be the nature of the last command.

~. Distinguish between ERASE and OOPS commands.

rase command removes objects from the screen. OOPS command brings back the object 'ased by the latest (or the last) erase command. OOPS is just the reverse of erase.

3. Illustrate the use of OOPS command. ommand: OOPS +-'

(a) Removed object in dotted lines

Fig.7

'he inner rectangle which was erased' by the last erase command (Fig. 7a) which is not een now (Fig.7b) is brought back (Fig.7c) after the issue of OOPS command.

14. Illustrate the use of Undo command.

A --------- B (5, 6) after L command (10, 6) . (a)

A _ .. _._-.-.----------.-------- B

After U command (AB removed)

(b)

Command : U +-'

The last command issued was L command and the line AB was draw n. U command given after line command undoes the line command, the last command. That means, the line AB vanishes. See Fig.8(b).

35. Circle command, line comman~ and arc command were issued one after another in the order given. What will happen if undo command is issued twice successively?

Undo command can be used any number of times. 2 undo commands issued in succession undoes the arc and line commands which are the last two commands. Circle will remain after the issue of Undo command twice.

36. Illustrate the use of Redo command.

Redo command reverses the previous Undo command. Redo can be used only once.

o

o

o

            Before U         Mter U            After Redo

            command        command        command

The line was drawn last by using L command. When U command was issued next, thf line vanished. Redo command issued immediately after U command reverses the effec1 of U. That means, the line appears again. (See Fig. 9)

37. State the use of Zoom command.

Zoom command is used to magnify or decrease the display size of objects. Command i,

            zoomorz@                   @ Ig/1

            Before Z          Fig.IO             Mter Z             Fig. 11

38. Zoom command is used only for magnifying the size of objects. True / false False. Zoom command is used for both magnifying the size or decreasing the size oj objects.

39. State the different object selection methods.

The different object selection methods are i) selection with the mouse ii) All/multiple iii; Window iv) crossing v) last/previous vi) remove vii) single viii) W PolygoniC Polygon.

40. Distinguish between window and crossing methods of object selection.

In the window method, a window like area surrounds objects to be selected as shown in Fig. 11. All the objects lying wholly within the window are selected. Objects partly within and partly outside the wincl:t>w are NOT selected. In crossing, objects lying within the window and also objects crossing the boundary of the window are selected.

41. Distinguish between W Polygon and C Polygon method of object selection. W Polygon is used to select objects lying within a polygon. C Polygon is used to select objects lying within the crossing polygon.

42. State how dynamic option of zoom command is used.

Dynamic option is used to zoom the portion of the drawing included within a view box. The view box can be reduced or enlarged. It can be moved anywhere within the drawings.

43. What are the three ways in which scale option of the Zoom command can be used?

Scale option of Zoom command is used to increase or decrease the display size of the drawing. It can also be effectively used to alter the model paper scale ratio and thus t<J display the different parts of the drawing in different sizes.

44. How is HATCH command implemented in AutoCAD?

B hatch or H command is used to fill a closed area with a selected hatch pattern. Boundary hatch dialog box appears when Hatch command is given. The required pattern of hat chi nil

is selected by clicking on 'pattern' and then on the required pattern in the hatch pattern palette. By using Advanced option, one of the three styles of hatching is selected. The

thregeBhOWa ••

Outer

Fig. 12

45. State the uses of DDCHPROP and CHPROP commands (change prop commands.

Both the commands are used to change the colour, linetype, layer and thickness of existing objects. DDCHPROP uses dialog box to change properties. The command CHPROP does not display any dialog box.

46. State the use of OFFSET command.

Offset command is used to draw parallel lines, concentric circles, parallel arcs and parallel polylines.

47. State the two options of offset command.

Offset distance and Through are the two options of offset command. Offset distance option is used to draw parallel entities at specified offset distance. Through option is used to draw parallel entities at any point.

48. State the different types of commands used for dimensioning different entities.

Dimlinear or DLI, Dimaligned or DAL, Dimradius or DRA, Dimdiamattr or DDI, Dimcenter or DCE, Dimangular or DAN and Dimordinate or DOR are the different commands used for dinlensioning.

49. What is base line dimensioning?

In base line dimensioning, linear, angular or ordinate dimensions are made from the same base line of the selected dimension. Command is Dim baseline or DBA.

50. Illustrate the use of base line dimensioning for dimensioningthe steps shown

in Fig.13.                                 2

The steps are drawn keeping ORTHO on. Complete the                   2

dimensioning of the first step (Dimension 2) using    2

D1..mh.nea-r. Use Dimbase line command for placing the                                        Fig.13

dimensions 4 ann Q start.):n.~ Vlit\\. t\\.e same base Yme.

51. Explain how continued dimensioning is eJ(ecuted ? Command Dimcontinue or DCO is used for making continued dimensioning. Here, dimensions are continued from the second extension line of the already existing linear, angular or ordinate dimension. (See Fig. 14)

54. State the three types of 3D modelling.

Types of 3D modelling are i) wire-frame modelling ii) surface modelling and iii) solid modelling.

55. What is wire-frame modelling?

Wire-frame model is a 3D representation of objects by using mostly lines, arcs and circles. It is skeletal and does not have surfaces. Only edge details are shown by a wire frame model (See Fig.15).

56. What is surface modelling?

In surface modelling, the 3D object is made up of opaque surfaces (3D faces). The inner portion of the object is hollow. The details available behind the surfaces are hidden.

57. What is solid modelling?

In solid modelling, a solid 3D object is produced. It is like a solid object made of a material like wood. The solid thus produced "Can be cut into pieces. Mass properties of solid models can be determined (See Fig.16).

58. What is the use of box command?

Box command is used to draw three-dimensional solid box. To see the box as a three dimensional object, view point should be altered from 0, 0, 1 to some other point, (say) 1, 1, 1.

59. What is the use ofVPOINT command?

VPOINT command is used to specify the viewing direction for a three dimensional visualisation of the drawing. VPoint locates the observer in a specified position to look at the drawing back at the origin 0, 0, 0.

60. State the limitation of VPOINT command.

VPoint can be applied only in model space and not in paper space.

61. What is the use of view point option'!

Different views can be obtained by entering different view point values. 0, 0, 1 gives top view; 0, -1, 0 gives front view; 1',0,0 gives right view and -1,0,0 gives left view. View point option is used to enter different view point values.

62. What is the use ofVPORTS command.

VPORTS command is used to divide the screen (graphics) area into a number of tiled view-ports. TILEMODE available on the status bar should be switched on before issuing VPORTS command.

63. State any three options under VPORTS command.

Horizontal option divides the area into 3 horizontal view-ports. Vertical option diviqes the area into 3 vertical view-ports. 2 Option divides the area into two halves either vertically or horizontally. 4 option divides the area into 4 equal view-ports. Join option is used to join two adjacent view-ports into a larger view-port.

64. A -- is a rectangular part of the graphics area of the screen. Ans: View-port

65. What is the use of cylinder command?

Cylinder command is used to draw a three dimensional solid cylinder.

66. State the uses of CONE and SPHERE commands.

Cone command is used to draw a three dimensional cone. Sphere command is used to draw a three dimensional solid sphere.

9

Elevation

If

67. Illustrate elevation and thickness of an entity.

Fig 17(a) illustrates elevation and Fig.17(b) shows thickness of an entity. Command used for drawing the elevation is Elevation. Elevation command is also used to set extrusion thickness properties of new objects.

            (a)        Fig.17 (b)

68. Distinguish between elevation and thickness commands.

Elevation and thickness set by using ELEV command become permanent. Subsequent extrusion of objects is thus not possible. Thickness set by using thickness or TH command can be altered if needed.

69. State the use Of UNION command.

Union command is used to draw a composite region or solid by adding different regions or solids. A composite region is formed by combining two or more

            _9-1     ~ r:v Lj

Solids before Union .' is after Union Fig.I8 (b)

            Fig.19 (a)         Fig.19 (b)

71. What is the use of MASSPROP?

Massprop command is used tonetermine the mass properties of solids or regions. In the case of co-planar and non co-planar regions, the properties displayed are area, perimeter, centroid, moment of inertia, products of inertia, radii of gyration and principal moments. In the case of solids, the properties displayed are mass, volume, centroid, moment of inertia, products of inertia and radii of gyration.

72. What is meant by extrusion?

Extrusion is the process of drawing solids by extruding existing two-dimensional objects. If a taper angle is entered, the object is extruded in a tapered manner. Positive angle tapers the object in the positive z-direction. Negative angle tapers the object

Fig.20

in the negative z-direction. Fig.20(a) and (b) show an object PI extruded in the positive z direction. Fig.20(c) shows positive tapered extrusion. Fig.20(d) shows negative taperec extrusion.

73. Illustrate the method of drawing the sectional view by using AutoCAD. Command SECTION or SEC is used to draw a region obtained by intersecting solid: with a plane. 3 points option creates a plane passing through three given points. )0 option keeps the plane parallel to xy plane of the current DCS.