1. Agenda Learn to create an isometric sketch
Introduction To Engineering Communication by Sketching Isometric Pictorials - 2
Agenda
Learn to create an isometric sketch
This session briefly highlights materials in 1st Chapter of IGCE and starts on Chapter 2 – Isometric Sketching and Multi-view Drawings.
Students will see there are many ways to represent a 3-D object on a flat (2-D) piece of paper. Some are sued more often than others.
Students will see a video on making one of the most common types of 3-D pictorial, an isometric pictorial, practice making one in class, and then do some more isometric pictorials for homework.
Sketching - 2

2. Introduction to Projections – Four Basic Types
Axonometric
Oblique
Perspective
Multi-view
The multi-view drawing shows one side of an object in each view. Pictorials show 3 sides of an object in one view. The axonometric pictorial is used most commonly and the isometric pictorial is the most frequently used axonometric pictorial. It is the one we will focus on.
Architects use perspective pictorials. Cabinet makers used to use oblique pictorials because they show the front view without disortion.
Pictorials
Sketching - 2

3. Introduction to Isometric Projection
 CUBE 
Isometric Projection:
One type of axonometric pictorial projection
‘Iso-’ means ‘equal
‘metric projection’ means ‘a projection to a scaled measure’
The three dimensions are not only shown in one view, but also the dimensions can be scaled from this drawing
START WITH A CUBE
All of the normal drawing planes (top, front, side) are equally foreshortened or tilted, and all of the major axes (X, Y, Z) are at equal rotations from each other (120 degrees apart), as in the illustration above.
And, because all of the major planes are equally foreshortened, all of the measurements in these planes are equal as well as shown above. This means that the same measuring scale may be used in drawing both the width, height, and depth of objects.
The term Isometric literally means equal measure
All planes are equally or proportionately shortened and tilted
All the major axes (X, Y, Z) are 120 degrees apart
Sketching - 2

4. Making an Isometric Sketch
- Defining Axis
30o
60o
Derive the axes from a vertex of the cube
Isometric Axis
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5. Making an Isometric Sketch - Axis Convention
Depth
Width
Height
The 3 principal dimensions of an object are height (H), width (W), and depth (D).
When making an isometric pictorial, the students should determine the maximum H, W, and D of the object and lightly sketch a box with those three dimensions. The isometric pictorial of the object will fit within that box.
Isometric Axis Convention
Sketching - 2

6. Use of the grid paper Correct orientation Incorrect orientation
Explain the use of grid paper –
Instructions on the grid paper used for isometric sketches indicate to turn paper sideways. If the student doesn’t orient the paper properly, the sketch of the object will look distorted.
Correct orientation
Incorrect orientation
Note the alignment of the axes
Sketching - 2

7. Object for Practice (in-class)
Everyone should participate in this example in class
The first step is to draw a box whose dimensions are the H, W, and D of the object. The box represents the piece of wood that a machinist might select to begin carving the object pictured. The box should be sketched in very light lines.
The machinist would then cut away the pieces of the wood not needed for the final object. We will do that same process on paper. We will do that same process on paper.
Sketching - 2

8. Blocking in the Object – Begin with Front Face
Height
Width

9. Blocking in the Object – Add Side Face
Height
Depth
Side Face

10. Blocking in the Object – Add Top Face

11. Adding Detail – Cut Outs – Part 1
DO TOGETHER THROUGH 15
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12. Adding Detail – Cut Outs – Part 2

13. Adding Detail – Cut Outs – Part 3

14. Darken Final Lines – Part 4
Note:
All visible edges
will be darkened

15. Summary Technical drawings are an effective communication media
Projections of various types can be used
Isometric projections and creating isometric sketches has been introduced
Assignments will emphasize simple isometric sketches
Summarize the objectives of the session
Will introduce more advanced isometrics and multi-view drawing later.
Sketching - 2

16. Assignments Assignments 1 and 2 – Due tomorrow
Make an isometric sketch of the following from Bertoline:
Assignment 1: Pg. 56, Problem 2.9 #(6)
Assignment 2: Pg. 57, Problem 2.9 #(22)
Use isometric grid paper
To help students avoid common errors:
Encourage them to follow Sketching and Text conventions – complete the reading assignment before drawing
Reading assignment could be done in the class.
Students are encouraged to leave the construction lines – much lighter and thinner than the finished lines
Do not try to shade drawing – this is not a pencil sketching class.
Use grid paper, when available. Try to sketch along grid lines. Practice sketching straight lines and curves on a grid sheet
Tips for drawing 2:
Do not draw a cube or a cuboid and call it an eraser or shoe-box. Be creative.
Sketching - 2