151 ME Descriptive Geometry
Larson & McFarland Spring 2011
Descriptive Geometry:
True Length of a Line: 1. Draw a fold line parallel to any view of the line. 2. Project end points of line into new view remembering that projection lines are always perpendicular to fold lines. 3. Measurements are always made two views back from the new view. Measure in the front view (F) and transfer to auxiliary view (A1).
Descriptive Geometry:
Can you identify where the measurements for the True Length views could have been taken?
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ME 151 Descriptive Geometry
Larson & McFarland Spring 2011
Descriptive Geometry:
True Length of a Line: Where would the new fold line be drawn for the line shown?
Descriptive Geometry:
True Length of a Line: How about the new fold line on this example?
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ME 151 Descriptive Geometry
Larson & McFarland Spring 2011
Descriptive Geometry:
True Length of a Line: Finally, the fold line for this line?
Descriptive Geometry:
Point View of a Line: 1. Must have the true length view of the line. 2. Make a fold line perpendicular to the true length line. 3. Measurements are always made on the views adjacent to the measurements for A2 view come from the T view.
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ME 151 Descriptive Geometry
Larson & McFarland Spring 2011
Descriptive Geometry:
Shortest Distance between two Skew Lines: 1. Construct the True Length view of one of the lines. 2. Construct the Point View (PV) from the True Length line. 3. The Shortest Distance between the lines is the perpendicular distance between the PV of the line and the other line.
Descriptive Geometry:
Shortest Distance between two Skew Lines: 1. Construct the True Length view of one of the lines. 2. Construct the Point view (PV) from the True Length line. 3. The Shortest Distance between the lines is the perpendicular distance between the PV of the line and the other line.
Fold line parallel to line 3-4 to get true length.
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ME 151 Descriptive Geometry
Larson & McFarland Spring 2011
Descriptive Geometry:
Shortest Distance between two Skew Lines: 1. Construct the True Length view of one of the lines. 2. Construct the Point view (PV) from the True Length line. 3. The Shortest Distance between the lines is the perpendicular distance between the PV of the line and the other line.
Descriptive Geometry:
Shortest Distance between two Skew Lines: 1. Construct the True Length view of one of the lines. 2. Construct the Point view (PV) from the True Length line. 3. The Shortest Distance between the lines is the perpendicular distance between the PV of the line and the other line.
Fold line perpendicular to TL line to get point view.
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ME 151 Descriptive Geometry
Larson & McFarland Spring 2011
Descriptive Geometry:
Shortest Distance between two Skew Lines: 1. Construct the True Length view of one of the lines. 2. Construct the Point view (PV) from the True Length line. 3. The Shortest Distance between the lines is the perpendicular distance between the PV of the line and the other line.
Descriptive Geometry:
Shortest Distance between two Skew Lines: 1. Construct the True Length view of one of the lines. 2. Construct the Point view (PV) from the True Length line. 3. The Shortest Distance between the lines is the perpendicular distance between the PV of the line and the other line.
Shortest distance between lines measured from PV perpendicular to line 1-2.
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ME 151 Descriptive Geometry
Larson & McFarland Spring 2011
Descriptive Geometry:
Shortest Distance between two Skew Lines: 1. Construct True the Length view of one of the lines. 2. Construct the Point view (PV) from the True Length line. 3. The Shortest Distance between the lines is the perpendicular distance between the PV of the line and the other line.
Shortest distance 5-6 must be TL, therefore it is parallel to A2-A1 fold line in A1 view.
Descriptive Geometry:
Shortest Distance between two Skew Lines: 1. Construct the True Length view of one of the lines. 2. Construct the Point view (PV) from the True Length line. 3. The Shortest Distance between the lines is the perpendicular distance between the PV of the line and the other line.
Shortest distance projected into F view, point 5 on line 1-2 and point 6 on line 3-4.
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ME 151 Descriptive Geometry
Larson & McFarland Spring 2011
Descriptive Geometry:
Shortest Distance between two Skew Lines: 1. Construct the True Length view of one of the lines. 2. Construct the Point view (PV) from the True Length line. 3. The Shortest Distance between the lines is the perpendicular distance between the PV of the line and the other line.
Shortest distance projected into S view, point 5 on line 1-2 and point 6 on line 3-4.
Descriptive Geometry:
Edge View of a Plane: 1. Must have a true length line. Inspect for existing TL, or construct a TL line on existing views. 2. Make a fold line perpendicular to the true length line to obtain PV. 3. When the TL line goes to PV, the plane will appear as an Edge View.
No true length lines exist on either view.
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ME 151 Descriptive Geometry
Larson & McFarland Spring 2011
Descriptive Geometry:
Edge View of a Plane: 1. Must have a true length line. Inspect for existing TL, or construct a TL line on existing views. 2. Make a fold line perpendicular to the true length line to obtain PV. 3. When the TL line goes to PV the plane will appear as and Edge View.
Construct a true length line on the existing views.
Descriptive Geometry:
Edge View of a Plane: 1. Must have a true length line. Inspect for existing TL, or construct a TL line on existing views. 2. Make a fold line perpendicular to the true length line to obtain PV. 3. When the TL line goes to PV the plane will appear as and Edge View.
Construct a fold line perpendicular to TL line. TL line goes to PV and plane goes to EV.
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ME 151 Descriptive Geometry
Larson & McFarland Spring 2011
Descriptive Geometry:
True Shape View of a Plane: 1. Must have a true length line. Inspect for existing TL, or construct a TL line on existing views. 2. Fold line perpendicular to the true length line to obtain PV & EV. 3. Fold line parallel to EV to obtain True Size and Shape View. TL line constructed since no TL exists on either view.
Descriptive Geometry:
True Shape View of a Plane: 1. Must have a true length line. Inspect for existing TL, or construct a TL line on existing views. 2. Fold line perpendicular to the true length line to obtain PV & EV. 3. Fold line parallel to EV to obtain True Shape View.
New fold line perpendicular to TL to get PV of line and EV of plane.
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ME 151 Descriptive Geometry
Larson & McFarland Spring 2011
Descriptive Geometry:
True Shape View of a Plane: 1. Must have a true length line. Inspect for existing TL, or construct a TL line on existing views. 2. Fold line perpendicular to the true length line to obtain PV & EV. 3. Fold line parallel to EV to obtain True Shape View. New fold line parallel to EV to get true shape of plane.
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