orthographic projection, multi-view drawings, & precedence of lines
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Orthographic Projection, multi-view drawings, & Precedence of lines. North Carolina State University Spring 2013. What You Will Learn:. Define Orthographic Projection. Correctly label the placement of the six standard views of an object drawing. - PowerPoint PPT PresentationTRANSCRIPT
ORTHOGRAPHIC PROJECTION, MULTI-VIEW DRAWINGS, &
PRECEDENCE OF LINESNorth Carolina State University
Spring 2013
What You Will Learn:
Define Orthographic Projection.
Correctly label the placement of the six standard
views of an object drawing.
Identify which views are needed when creating a
multi-view drawing of an object.
Create a multi-view drawing with the correct views
from a given object.
Identify different types of lines used for drafting.
Identify which line types have precedence over others.
Create multi-view drawings using different line types.
SECTION 1:
ORTHOGRAPHIC PROJECTION & MULTI-VIEW DRAWINGS
Orthographic Projection
Orthographic Projection: (n) a parallel projection technique that creates a 2-D image of 3-D objects or structures on an image plane perpendicular to the lines of sight.
In The U.S. we use a method called Third Angle Projection
Used to represent all aspects of a 3-D object by only using 2-D drawings
Glass Box Method View each object
as if it were in a glass box.
When unfolding the box you have the 6 views of projection.
The 6 Views of Projection
Top – Looking down on an object (birds eye view)
Front – ALWAYS the most descriptive Right Side – To the right of the front view Bottom – opposite of the top Left Side – opposite of the right Back – opposite of the front
Proper Layout of a Multi-View Each view has a specific location as to
where it is placed in reference to others.
Creating a Multi-View Drawing Only use the views necessary to
visualize the full object. (Typically: top, front, right side)
Sometimes only two views are necessary such as when drawing a cylinder
Examples
Examples
INCORRECT CORRECT
Guided Practice: Create a multi-view
drawing of this object.
Label each view of your drawing.
Solution:
Guided Practice: Create a multi-view
drawing of this object.
Label each view of your drawing.
Solution:
Independent Practice: Create a multi-view drawing of the following two
objects. Label each view of your drawings.
Solution 1:
Solution 2:
SECTION 2:
LINE TYPES &PRECEDENCE OF LINES
Visible Lines:
Thick and Bold Often called construction lines or object
lines Used for the outer edges and visible
features of an object.
Hidden Lines:
Thin, dashed line Used to show hidden features within an
object which can not be seen from the outside of the object.
Center Lines:
Thin lines with alternating long and short dashes.
Show the center of both visible and hidden circular features such as holes, cylinders, etc.
Precedence of Lines
Precedence of Lines: The order in which different line types appear in an drawing based on importance.
Precedence of Lines:
Example:
Guided Practice: Create a multi-view
drawing of this object.
Label each view of your drawing.
Include visible, hidden, and center lines
Solution:
Guided Practice: Create a multi-view
drawing of this object.
Label each view of your drawing.
Include visible, hidden, and center lines
Solution:
Independent Practice: Create a multi-view drawing of the following two
objects. Label each view of your drawings. Include visible, hidden, and center lines
Solution 1:
Solution 2: