UTPA STEM/CBI Courses/Graphics/Introduction to Pictorial Drawings - Snap Cubes & Special Graph Paper

Course Title: Engineering Graphics

Lecture Topic: Introduction to Pictorial Drawings – Snap Cubes and Special Graph Paper

Instructor: Gregory Potter

Institution: UTPA

To visit the Engineering Graphics website click here

Backwards Design
Course Objectives


 * Primary Objectives- By the next class period students will be able to:
 * Draw a Cabinet Oblique Pictorial Sketch of a simple object
 * Draw a Cavalier Oblique Pictorial Sketch of a simple object
 * Draw a Isometric Pictorial Sketch of a simple object


 * Sub Objectives- The objectives will require that students be able to:
 * Convert a multi-view drawing into one of three types of pictorial sketches


 * Difficulties- Students may have difficulty:
 * Determining the difference between the three types of pictorial drawings


 * Real-World Contexts- There are many ways that students can use this material in the real-world, such as:
 * During all phases of the engineering design process
 * To communicate ideas before CAD models can be generated

Model of Knowledge


 * Concept Map
 * Pictorial Sketches can be used to document the initial phases of the design process.
 * Pictorial Drawings can be used to communicate dimensions, for manufacturing purposes, or for illustrative purposes.


 * Content Priorities
 * Enduring Understanding
 * Students must understand how to draw all three types of pictorial sketches given a simple object.
 * Important to Do and Know
 * The difference between the three types of pictorial sketches
 * Worth Being Familiar with
 * Parallel projection
 * Online location of special graph paper - Click here to see Special Graph Paper

Assessment of Learning


 * Formative Assessment
 * In Class (groups)
 * Examples by instructor during lab
 * Worksheet assignment on website
 * Homework (individual)
 * Simple parts pictorial sketches


 * Summative Assessment
 * Quiz at the end of lab
 * Question on Exam 1

Legacy Cycle
OBJECTIVE

By the next class period, students will be able to:
 * Draw all three types of pictorial sketches (Cavalier Oblique, Cabinet Oblique, Isometric)

The objectives will require that students be able to:
 * convert information from a multi-view sketch into a pictorial sketch

THE CHALLENGE

This exercise will take place during the third week of Engineering Graphics Lab as an introductory assignment. It is designed to give the students tactile experience making the shape with Snap Cubes before attempting to sketch a pictorial drawing. This assures that the student is visualizing the shape accurately before the pictorial sketches are started.

GENERATE IDEAS

Give the students Snap Cubes so that they are able create the shape above. Possible questions:
 * Why does the cavalier sketch look stretched?
 * This is intended to point out the differences between the different types of pictorial drawings.
 * The cavalier sketch looks stretched because the depth lines are drawn to the same dimension as the actual part. When using the oblique graph paper, this produces a stretched image.
 * Why does the cabinet sketch look right?
 * The cabinet oblique has depth lines that are one-half the actual depth. When drawn using the oblique graph paper, the part looks closer to what the human mind perceives as correct.
 * How is the isometric pictorial different from cavalier and cabinet pictorials?
 * The isometric pictorial has vertical lines in the height dimension and width and depth lines at ±30°.
 * The cavalier and cabinet oblique pictorials have vertical and horizontal lines for height and width, but the depth lines are at 45°.

MULTIPLE PERSPECTIVES

Ask students to create multiple shapes from pictorial drawings. The instructor can give some examples using shape from previous multi-view exercises. The students should be following along until they feel comfortable trying on their own.

RESEARCH & REVISE

Give students other shapes to draw using the standard pictorial views so that they may familiarize themselves with the process during the lab. A tutorial movie is available on the website. Students can access these movies to practice and review before quizzes and exams. Below is a screenshot showing some of the examples drawn during the tutorial movie. These are shapes taken from the 4 worksheets completed in Lesson 1. The students are already familiar with the shapes, so they can concentrate on the subject of pictorial sketches.

TEST YOUR METTLE

Assign homework designed to exercise the skills learned during this exercise. The figure below shows the puzzle cube the students are required to draw and model (both pictorial sketches and CAD) for homework.

GO PUBLIC

Quiz students for a grade at the end of the lab.

Pre-Lesson Quiz
Give the students Snap Cubes so that they are able create the following shape (previously shown).

Test Your Mettle Quiz
Quiz will consist of displaying a block shape in isometric form and asking students to draw cavalier and cabinet oblique pictorial sketches. There will also be a specific question on the first exam where the students will use the skills learned during the multi-view and pictorial sketch lessons.