Engineering Drafting is explored by the use of ACAD 2002. The above model is named the Gage Holder. There are many tools that are used in Engineering to hold a device that measures surfaces. The angled surface at the base of this part holds the device within a track where the part can be moved and secured into position by its 2 horizonatal mounting holes.

Drawing this part because of its non isometric surfaces requires a technique called: "Circle Projection", in order to accurately illustrate those surfaces. In the Lesson Media disk you will be instructed in detail about how to used this technique to draw this model's Isometric Projection.

Connecting Your Learning

As you work your way through this lesson, you should reflect on the following questions:

What is the function of a typical Gage Holder?
How is "Circle Projection" used in Isometric Projection?
What are Projection lines?
What is a non isometric line?

The State of Arizona has assembled Drafting standards to make sure that Instruction is thorough and well thought out by the instructor. By clicking on the hyperlink below will upload to your browser window the entirety of these standards. The standards that are addressed in this lesson are below the hyperlink.

1.0 USE BOARD DRAFTING EQUIPMENT, INSTRUMENTS AND MEDIA.

• 1.1 Analyze Drawing surfaces for Drafting
• 1.6 Demonstrate Sheet Setup skills

2.0 DEMONSTRATE SKETCHING, LETTERING, AND LINE SKILLS.

• 2.1 Demonstrate freehand sketching skills for drafting applications.
• 2.2 Demonstrate lettering skills.
• 2.3 Demonstrate line work.

6.0 DEMONSTRATE GEOMETRIC CONSTRUCTIONS

• 6.1 Measure Geometric Constructions.
• 6.2 Develop Geometric Constructions.

8.0 APPLY BOARD DRAFTING SKILLS TO COMPUTER-AIDED DESIGN/DRAFTING (CADD)

• 8.1 Demonstrate computer skills for a CADD system.
• 8.2 Create dimensional CADD entities.
• 8.3 Create 3 dimensional CADD drawings.

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The State of Arizona has also assembled Math standards and many of these apply directly to the vocational subject area of Drafting. Drafting is a very precise discipline and the use of mathematics is integral to design and manufacturing. Below are the math standards that are involved in this lesson

1M-P1. Compare and contrast the real number system and its various subsystems with
regard to their structural characteristics

• PO 2. Compare subsets of the real number system with regard to their properties
  (commutative, associative, distributive, identity, inverse and closure properties)

1M-P2. Construct, interpret and demonstrate meaning for real numbers and absolute

• PO 3. Solve real-world distance problems using absolute value
• PO 4. Determine, among the solutions to a real-world problem, which, if any, is reasonable
• PO 2. Define absolute value as the distance from the origin

4M-P1. Interpret and draw three-dimensional objects

• PO 1. Sketch prisms, pyramids, cones, cylinders and spheres
• PO 2. Classify prisms, pyramids, cones, cylinders and spheres by base shape and lateral surface shape.
• PO 3. Recognize the three-dimensional figure represented by a two-dimensional drawing.
• PO 5. Make a model of a three-dimensional figure from a two-dimensional drawing and make a two-dimensional representation of a three-dimensional object (models and representations include scale drawings, perspective drawings, blueprints or computer simulations)

4M-P4. Deduce properties of, and relationships between, figures from given
assumptions

• PO 1. Find similarities and differences among geometric shapes and designs using a given attribute (e.g., height, area, perimeter, diagonals and angle measurements)
• PO 2. Identify arcs, chords, tangents and secants of a circle
• PO 3. State valid conclusions using given geometric definitions, postulates and theorems
• PO 4. Represent pi as the ratio of circumference to diameter
  

 

Lesson Objectives

1. Draw the orthographic views and dimension according to ASME14.5 using ACAD 2002.
2. Identify the isometric angles used to create isometric views (30, 90 and 150 degrees)
3. Understand how to use the commands of : line, copy, move, the @ command and vectoring,
4. Draw an Isometric view from orthographic views.
5. Center orthographic models in paper space using 1.5" between views.
6. Identify the working view of a model and its front, top and side views.
7. Using the scale command correctly for 1/2 scale orthographic's.
8. Understand and use circle projection to determine an non_isometric angle.

Key Terms

"click on the key on any of these terms and it will hyperlink to the course glossary"

isometric	array	guide	orthographic
Illustrator	grid	unidirectional	aligned
font	line weight	scale	dimension
layers	extension lines	circle projection	move

 

Instruction

Your Text Book and Reading Assignments

Summary and Assessment