Orthographic DrawingGrade 9 - TLE

Prepred by:Ms. Arlyn P. BonifacioTLE Teacher

Objectives

• Define orthographic drawing.• Explain the importance of the alphabet of

lines in constructing orthographic figures.• Define pictorial drawing.• Draw different kinds of pictorial drawing.• Explain the basic principles of pattern

development.

Orthographic Drawing

• The term Orthographic is derived from two Greek Works:

“Straight”

“to draw”

“…it describes a type of drawing represented only by lines without shading or rendering.”

What is orthographic Drawing?

Is the method of representing the exact shape and size of a given object in one or several views.

Others call it “multi-view drawing” because it represents not only one but several views which are projections of an object as observed in one surface.

WHAT IS ALPHABET OF LINES

• The basis of all drawings is lines.

• Many different lines are used even in sample drawings.

• All lines should be made so clearly that there will be no doubt of their meaning when the drawing is read.

Alphabet of Lines

• Border Line Is the heaviest and darkest line in a drawing. It surrounds a drawing and is usually rectangular in shape.

Alphabet of Lines

• Visible Lines Are sometimes called object lines. These represent the visible outline or parts of an object.

Alphabet of Lines

• Hidden or

invisible linesThese lines consist of small or short dashes about 3-4 millimeters long, with gaps in between that are about 1-2 millimeters wide.

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Alphabet of Lines

• Center line It is the lightest line or finest line in a drawing. It consists of one long dash and one short dash alternately drawn. It is used to indicate the centers of entire objects and locations of circular features.

Alphabet of Lines

• Projection or

extension lines

Are continuous lines extending from a view to show clearly the dimension limits.

Alphabet of Lines

• Dimension

Line

It consists of three parts:Arrow heads, fine line and number of measurements. It is used to indicate the measurements of an object.

6.00

Alphabet of Lines

• Reference

Line

It is an irregular, fine, curved line with an arrowhead at one end. It is used to label the parts of an object.

Alphabet of Lines

• Leader Line Is a broken line with an arrowhead at one end. It is used for indicating the measurements and name of a part.

Alphabet of Lines

• Limiting line Is used for limiting the length of an elongated object, so that it can be shown without changing the size of its view.