Drafting and Computer-Aided Design Main Menu

Core and Optional Modules

Module 5: Pictorial Drawings (Core)

Suggested Time: 15-20 hours	Level: Introductory
Prerequisite: Module 1 or 2

Foundational Objectives

To understand the representation of three-dimensional objects presented on a two-dimensional plane.
To appreciate the concept of scale and proportion.
To maintain a high standard of quality for drawings produced.

Common Essential Learnings Foundational Objectives

To produce pictorial drawings. (TL)
To use the language and terms specific to the drafting of drawings. (COM)

Note: other CELs may be emphasized here.

Learning Objectives Notes
5.1 To produce isometric drawings. (TL) Define, explain and show illustrations of isometric drawings.

Start with objects that will require only isometric lines to draw.

Then draw objects with some non-isometric lines. Show how the non-isometric lines are not parallel to any of the isometric axis. (NUM)

Objects containing circles and arcs can be drawn once the basics have been mastered.
5.2 To produce oblique cavalier drawings. Define, explain and show illustrations of oblique cavalier drawings.

Start with objects that will require only straight lines.

Student should understand that circles and arcs should be placed on the front plane of the oblique drawing so they are not distorted.
5.3 To produce oblique cabinet drawings. (COM) Define, explain and show illustrations of cabinet drawings.

When arcs and circles appear on more than one plane it is better to use an isometric drawing.

The face of the object with the longest dimensions should be placed parallel to the front plane.

Module 6: Basic Dimensioning (Core)

Suggested Time: 15-20 hours	Level: Introductory
Prerequisite: Module 1 or 2

Foundational Objectives

To be able to describe size on a multi-view drawing.
To be able to use and understand the terminology related to drafting.
To maintain a high standard of quality for drawings produced.

Common Essential Learnings Foundational Objectives

To choose an appropriate scale ratio for drawings. (NUM)
To develop knowledge of the use of technology in the field of drafting. (TL)

Note: other CELs may be emphasized here.

Learning Objectives Notes
6.1 To use terminology in context. (COM) Define: extension lines; dimension lines; arrowheads; leaders; diameter symbols; radius symbols; and, aligned and unidirectional dimensioning.
6.2 To apply dimensions. (NUM, TL) When using CAD software, the scale of the final plotted drawing will determine the size of the text to be used and the distances dimension lines are placed from the object. Therefore the title block must be placed before dimensioning starts.

Start by dimensioning drawings that will be plotted at a scale of 1:1. (NUM)

Discuss what countries use third-angle/first-angle projection.

Start with simple objects that only have straight lines that require only overall dimensions.

Next, introduce objects that require intermediate dimensions.

Then, introduce dimension objects with simple holes, arcs and cylinders using leaders and the correct symbols. (TL)

Discuss both aligned and unidirectional dimensioning but use only unidirectional dimensioning to avoid confusion.
6.3 To use proper standards or rules for dimensioning objects. (CCT) The rules for dimensioning should be introduced as the students go through the steps of dimensioning.

Students should understand that there is always more than one way to dimension each object, but usually one way is better than the others.

Important rules should be emphasized, such as: try to group dimensions; place dimensions between the views; never dimension hidden lines; dimension to the center of arcs and circles; dimension circles with a diameter symbol; dimension arcs with a radius symbol; try not to use long extension lines; try not to cross extension lines; and, the correct placement of leaders.

	Learning Objectives	Notes
5.1	To produce isometric drawings. (TL)	Define, explain and show illustrations of isometric drawings. Start with objects that will require only isometric lines to draw. Then draw objects with some non-isometric lines. Show how the non-isometric lines are not parallel to any of the isometric axis. (NUM) Objects containing circles and arcs can be drawn once the basics have been mastered.
5.2	To produce oblique cavalier drawings.	Define, explain and show illustrations of oblique cavalier drawings. Start with objects that will require only straight lines. Student should understand that circles and arcs should be placed on the front plane of the oblique drawing so they are not distorted.
5.3	To produce oblique cabinet drawings. (COM)	Define, explain and show illustrations of cabinet drawings. When arcs and circles appear on more than one plane it is better to use an isometric drawing. The face of the object with the longest dimensions should be placed parallel to the front plane.

	Learning Objectives	Notes
6.1	To use terminology in context. (COM)	Define: extension lines; dimension lines; arrowheads; leaders; diameter symbols; radius symbols; and, aligned and unidirectional dimensioning.
6.2	To apply dimensions. (NUM, TL)	When using CAD software, the scale of the final plotted drawing will determine the size of the text to be used and the distances dimension lines are placed from the object. Therefore the title block must be placed before dimensioning starts. Start by dimensioning drawings that will be plotted at a scale of 1:1. (NUM) Discuss what countries use third-angle/first-angle projection. Start with simple objects that only have straight lines that require only overall dimensions. Next, introduce objects that require intermediate dimensions. Then, introduce dimension objects with simple holes, arcs and cylinders using leaders and the correct symbols. (TL) Discuss both aligned and unidirectional dimensioning but use only unidirectional dimensioning to avoid confusion.
6.3	To use proper standards or rules for dimensioning objects. (CCT)	The rules for dimensioning should be introduced as the students go through the steps of dimensioning. Students should understand that there is always more than one way to dimension each object, but usually one way is better than the others. Important rules should be emphasized, such as: try to group dimensions; place dimensions between the views; never dimension hidden lines; dimension to the center of arcs and circles; dimension circles with a diameter symbol; dimension arcs with a radius symbol; try not to use long extension lines; try not to cross extension lines; and, the correct placement of leaders.