sketching iso and ellispses
TRANSCRIPT
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Isometric ellipsesIn an isometric drawing, the object is viewed at an angle, which makes circles appear as ellipses.
Holes
Cylinders
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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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Introduction to Isometric Projection
• Isometric means equal measure• All planes are equally or proportionately shortened and tilted• All the major axes (X, Y, Z) are 120 degrees apart
CUBE
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Step 2 – Ellipse on Front Face
Lines to Tangent Points
- Lines to tangent points- Corner to corner to get center
Tangent Points
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Step 3 – Ellipse on Back Face and Profile
Draw Tangent Lines for ProfileComplete Visible Part of Back Ellipse
Repeat for ellipse on rear face
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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
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Review Questions1. _______ sketches present the object in a single
view, with all three dimensions represented2. _______ 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)?
a) b) d)c)120°
120°120°
60° 60°
240°
60°90°
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• 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
Tips for Drawing Assignments
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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.
Tips for Drawing Assignments
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Tips for Pictorial ViewsIn 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
viewIn 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.