1. Part 2: Plotting the Course
- Planning & Organizing Drawings

2. Objectives Of This Lesson
Discuss what you must consider in planning and organizing drawings attention must be paid to the setting up of drawings.
Discuss the concept of using Layer/Levels in organizing content within drawings. Discuss manipulating object's properties.
Identify CAD drawing components.

3. Overview
In planning and organizing drawings attention must be paid to the setting up of drawings. You must consider the following:
What dimensional units and drawing units will be used ?
What linework\Linetype will be used ?
How will the information be organized, be it textual or graphical, for easy manipulation and editing ?

4. Overview (cont.)
You can work with various units of measure, such as architectural units, engineering units, scientific units and surveyor's units. These units can be represented in different formats commonly used by professionals.
Architectural units
Scale:
1/8"=1'-0"
1/4"=1'-0"
1/2"=1'-0"
Decimal units
Scale:
1"=10'
1"=20'
1"=100'
Angular units
0d10'20"
However, It is important to note that the practice in an engineering cad program the user draws at a scale of 1:1. He/she then sets the plot layout to one of the above scales.

5. Overview (cont.) A Point to Note:
When you are working in engineering units, you can specify whether all the dimensions should be represented in inches (12"), feet-inches (1'-0"), centimeters ( 1 cm), or meters (m).
You can also choose to use angular units of measurements such as decimal degrees, minutes, seconds or radians.

6. Overview (cont.)
In general, when you need to work on a large scale drawings such as a plan of a village or industrial building site, you can use a lesser degree of accuracy, say 1'-0". The computer program will round off all the measurements to the next foot and no fractions of less than a foot will be shown.
However, when you need to do very detailed work, you should use an higher degree of accuracy such as 1/8th or 1/64th of an inch.

7. Setting up Drawings : Working with Linetype
Linetype refers to the nature of the object. It may be solid, dotted, dashed, or a combination of solid, dotted, and dashed segments.
Solid
Dotted
Dash
Long Dash Dash Dot
Dash Dot

8. Setting up Drawings : Organizing Information
Information should be organized, be it textual or graphical, for easy manipulation, editing and understanding. Layers in CAD are imaginary transparent surfaces. You can draw on these surfaces.
Layers / Levels are basically used to place similar information on the same [transparent] sheet. Multiple layers/levels can and do exist, including layers for object geometry, dimensions, notes, among others. Most CAD programs layer/level properties consists of a name/number, color, lineweight, and linetype..

9. Setting up Drawings : Organizing Information (cont.)
You can turn the layers/levels on or off to view or edit specific objects. When you turn a layer off, the objects on that layer disappear from the screen; when you turn it back on, they are displayed.

10. Setting up Drawings : Using LAYERS\LEVELS
When drawing information are placed on layers/levels is should be done using some type of standardized format. This is done so that others can readily interpret what is being conveyed graphically or textually.

11. Setting up Drawings : Using LAYERS\LEVELS
For example:
Let's say you want to layout a building and you want to show the following; Exterior walls, Interior walls, Doors and Windows
The layer\ level naming may labeled as such:
Description of Object
Interior Wall
Exterior Wall
Door
Window
Layer\Level Name
*A-Wall-Int
A-Wall-Ext
A-Door
A-Window
“A”, prefix for Architecture.
“C” for Civil.
“E/EL”, for Electrical,

12. Setting up Drawings : Using Linetype or Stroke
After the layer\level has been named with the description of the object(s), you can then assign a linetype or stroke to the objects that will reside on the layer.

13. Setting up Drawings : Using Linetype or Stroke (cont.)
For example:
Let's say you want the Exterior walls, Interior walls, Doors and Windows to be represented by a particular linetype\linework to distinguish it from other objects:
The layer\ level naming may labeled as such:
Description of Object
Interior Wall
Exterior Wall
Door
Window
Layer\Level Name
A-Wall-Int
A-Wall-Ext
A-Door
A-Window
Linetype\Stroke
Dashed
Solid
Hidden

14. Setting up Drawings : Using Lineweight
After the layer\level has been named with the description of the object(s), you can also assign a lineweight to the objects that will reside on the layer. A lineweight is how wide or thin a line\stroke will appear.
The following is an example only:
Type
Unit (Inches)
.007
.010
.013
.020 1 2 3 4
Unit (Point)

15. Setting up Drawings : Layer\Level Assigned Color
Now that we have named layers\levels, assigned a linetype; We can go another step and give the layer a color (or color number) to distinguish it more from the other objects in the drawing.
You would label it as such:
Description of Object
Interior Wall
Exterior Wall
Door
Window
Layer\Level Name
A-Wall-Int
A-Wall-Ext
A-Door
A-Window
Color
blue
green
black
red
Linetype\Stroke
Dashed
Solid
Hidden

16. Setting up Drawings : Layer\Level “Visibility”
Using the layer[level] feature is very advantageous when organizing your drawing. You can manage the objects in your drawing file by placing them on separate layers [levels]. Within this command you can change "visibility " of the objects appearing on the layer\level. This means the objects are either "visible" on the screen or the objects are "invisible", on the screen.
(Example use in a proprietary program)
Visible = ON/Thawed
Invisible = OFF/Frozen

17. Setting up Drawings : Layer\Level “Visibility” (cont.)
Following is an illustration of freezing/thawing layers\levels.
Visible = ON/Thawed
(Example use in a proprietary program)
Invisible = OFF/Frozen
Layer\Level Name
A-Wall-Int
A-Wall-Ext
A-Door
A-Window
State
Color
blue
green
black
red
Linetype\Stroke
Dashed
Solid
Hidden

18. Setting up Drawings : Layer\Level “Visibility” (cont.)
Visible = ON/Thawed
Invisible = OFF/Frozen
Let's say we wish to not view the exterior walls.
We would click to make the visibility state "Off/Frozen".
Layer\Level Name
A-Wall-Int
A-Wall-Ext
A-Door
A-Window
State

19. Setting up Drawings : Layer\Level “Visibility” (cont.)
Then the drawing would look something like this:
Layer\Level Name
A-Wall-Int
A-Wall-Ext
A-Door
A-Window
State
Off/Frozen

20. Setting up Drawings : Layer\Level “Visibility” (cont.)
Visible = ON/Thawed
Invisible = OFF/Frozen
Let's say we wish to not show the "interior wall”.
We would click to make the visibility state "Off/Frozen".
Layer\Level Name
A-Wall-Int
A-Wall-Ext
A-Door
A-Window
State

21. Setting up Drawings : Layer\Level “Visibility” (cont.)
Then the drawing would look something like this:
Layer\Level Name
A-Wall-Int
A-Wall-Ext
A-Door
A-Window
State
Off/Frozen

22. Setting up Drawings : Layer\Level “Visibility” (cont.)
Or choose to not show the “Text”.
Layer\Level Name
A-Wall-Int
A-Wall-Ext
A-Stair
A-Text
State

23. Setting up Drawings : Layer\Level “Visibility” (cont.)
Then the drawing would look like this:
Layer\Level Name
A-Wall-Int
A-Wall-Ext
A-Stair
A-Text
State
Off/Frozen

24. Setting up Drawings : Layer\Level “Visibility” (cont.)
Following is an illustration of changing object's colors (when layer/level dependent).
Layer\Level Name
A-Wall-Int
A-Wall-Ext
Color
blue
brown

25. Then the drawing would look like this:
Setting up Drawings : Manipulating Object's properties
We would simply change the color from dark brown to green on the layer\level the object(s) resides.
(Note: Must find the appropriate CAD command toolbar for the software in use.)
Then the drawing would look like this:
Layer\Level Name
A-Wall-Int
A-Wall-Ext
Color
blue
green

26. Setting up Drawings : Changing Linetype\Stroke
Following is an illustration of changing object's linetype\stroke.
Let's say we wish change the exterior walls from "solid" to "dashed"
Layer\Level Name
A-Wall-Int
A-Wall-Ext
Linetype\Stroke
Solid

27. Setting up Drawings : Changing Linetype\Stroke (cont.)
We would simply change the linetype of the exterior walls from solid to dashed.
(Note: Must find the appropriate CAD command toolbar for the software in use.)
Layer\Level Name
A-Wall-Int
A-Wall-Ext
Linetype\Stroke
Solid
Dashed
Changed to

28. CAD Drawing Components
CAD drawings are created by drawing individual components (also called drawing objects or entitles) of the drawing such as lines, arcs, dimensions and symbols.
Basic drawing components of CAD are lines, arcs, circles, ellipses, symbols, text, dimensions pointers, polylines, borders and patterns. You can complete most of the drawings by using these components in CAD.

29. CAD Drawing Components (cont.)
To draw any components of the drawing, you need to access a particular drawing command. There are separate commands to draw text, dimensions, patterns, symbols, and other elements of a drawing. The command can be entered by typing it in the command line, selecting it from the menu or by clicking on a specific tool button.

30. Concept of Layers/Level in CAD
Layers are imaginary transparent surfaces that can be created within a CAD drawing. You can draw on these imaginary surfaces and group drawing objects on different layers . This helps to organize CAD drawings and makes editing much easier.
Composite of all layers
LAYER xxx
LAYER 3
LAYER 2
LAYER 1

31. Concept of Layers/Level in CAD (cont.)
You can turn the layers on or off to view or edit specific objects. When you turn a layer off, the objects on that layer disappear from the screen, when you turn it back on, they are displayed. Using layers enables you to control the display of specific information on the screen by turning a combination of layers on or off.
TEXT ON, All others OFF
All layers ON
STAIR ON, All others OFF
WALL-INT ON, All others OFF
WALL-EXT ON, All others OFF

32. Concept of Layers/Level in CAD (cont.)
You may create dozens of layers in a drawing to isolate drawing objects. You may create separate layers to show walls, furniture, electric, heating, A/C renovation.
Architects and engineers often need to coordinate different engineering services in a plan. They can illustrate different engineering services on the same drawing using different layers. This helps them understand how one engineering service relates to another.

33. – The Coordinate System
The preceding was just a general overview to make one familiar with what's involved in understanding and using CAD
Up Next:
Part 3: The Bearings
– The Coordinate System