Fundamentals of Engineering

1
Fundamentals of Engineering

• Isometric Pictorials and Ellipses
• GSMST

2
Objectives

• Projections The Four Basic Types
• Creating Isometric sketches
• Sketching Ellipses

3
Projections Four Basic Types
Note Isometric is a special case of Axonometric
Axonometric
Pictorials
Oblique
Perspective
4
Introduction to Isometric Projection
?CUBE?

• Isometric means equal measure
• All planes are equally or proportionately
  shortened and
• tilted
• All the major axes (X, Y, Z) are 120 degrees
  apart

5

• Making an Isometric Sketch
• Defining Axis

6

• Making an Isometric Sketch
• Axis Convention

Choose the longest dimension to be the width or
the depth for optical stability
Front view
Isometric Axis Convention
7
Usage of the Grid Paper
Correct orientation
Incorrect orientation
Note the alignment of the axes
8
Going From Isometric to Rectilinear
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Object for Practice
10

• Making an Isometric Sketch
• Axis Convention

Choose the longest dimension to be the width (or
the depth) for optical stability
Isometric Axis Convention
Front view
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11
Blocking in the Object Begin with Front Face
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Blocking in the Object Add Side Face
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Blocking in the Object Add Top Face
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Adding Detail Cut Outs Part 1
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Adding Detail Cut Outs Part 2
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Adding Detail Cut Outs Part 3
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Darken Final Lines - Part 4
Note All visible edges will be darkened
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Draw the Isometric

• Use Isometric Grid Paper
• Block is 6 x 3 x 3

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Isometric View
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Draw the Isometric
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Draw The Isometric
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Sketching a Circle

• Draw a square whose sides are the diameter of the
  circle.
• At the center of each side define the point of
  tangency for the circle.
• Draw the diagonals of the square.
• Orient the paper so you can draw equal arcs to
  construct the circle

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Isometric ellipses

• In an isometric drawing, the object is viewed at
  an angle, which makes circles appear as ellipses.
• Holes
• Cylinders

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Ellipses Can be in Any of Three Planes
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Sketching an Isometric of a Hollow Pipe
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Step 1 Creating the Base Box
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Step 2 Ellipse on Front Face
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Step 3 Ellipse on Front Face
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Step 3 Ellipse on Back Face and Profile
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Step 4 Ellipse for Hole on Front Face
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Isometric of Hollow Pipe
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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

33
Review Questions

1. _______ sketches present the object in a single
   view, with all three dimensions represented
2. _______ sketches present the object in a series
   of projections, each one showing only two of the
   objects three dimensions
3. Which among the following is NOT an isometric
   axes (Hint Use the Isometric Grid paper for
   reference)?

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Tips for Drawing Assignments

• Follow Sketching and Text conventions.
• Title Information is required. Avoid labels on
  the sketch.
• Leave the construction lines MUCH lighter and
  thinner than the finished lines
• Include centerlines on isometrics

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Tips for Drawing Assignments

• Do not try to shade drawing this is not a
  pencil sketching class.
• Use grid paper. Try to sketch along grid lines.
  Practice sketching straight lines and curves on a
  grid sheet.

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Tips for Pictorial Views

• In pictorial views, hidden lines are not shown
  unless absolutely required for clarity, such as
• Non-visible bottom of a blind hole
• Important feature of object not in direct view
• In pictorial views, holes or notches without
  bottom/end visible should be assumed to go
  completely through the object.
• Centerlines are to be shown on all isometric
  pictorials.

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In Class Assignment

• Use Isometric Sketch Paper (ISP)