Transcript CHAPTER 3

CHAPTER 3:
Drafting Equipment
Mrs. Kampf
Engineering Graphics I
Drafting Board
Drawing sheet attached to it.
 9X12, 16X21 or 18X24
 Wood with vinyl cover
 Stay flat and straight

T-Square
A head that lines up with a true edge of
the drafting board
 Straightedge provides a true edge
 Metal, wood with plastic
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Triangles
Used with t-square
 45° has a 90° angle and two 45°
 30° -60° triangle has a 30° a 60° and a 90°
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Protractor
Used to measure or lay out angles
 right, acute, obtuse
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Irregular Curves
French curves
 Used to draw noncircular curves like
spirals and ellipses.
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Templates

Save time in drawing shapes of details.
Vellum
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Tracing paper that has been treated to
make it more transparent.
ANSI

American National Standards Institute
ISO

International Standards Organization
Paper
Size A - Letterhead 8.5” X 11”
 Size B - Tabloid 11” X 17”
 Size C - 17” x 22”
 Size D - 22” X 34”
 Size E - 34” X 44”
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Case instruments

Drawing instruments that come in a set.
Dividers
Lines can be divided and distances can be
transferred with this
 Bow and Friction-joint
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Compass
True circles or arcs can be drawn with
this
 Bow and Friction-joint
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Bow instruments
Can be adjusted with either a center
wheel or a side wheel
 Easy to use and accurate.

Graphite pencils
17 degrees of hardness or grades
 Grade you use depends on paper type,
line weight and darkness of lines made
 6B to 9H, #2/HB is middle
 Hardness, Blackness, Fine Point
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Eraser

Vinyl erasers for film, kneaded, pink pearl,
gum, Magic rub
Erasing shield
Use to avoid erasing nearby lines
accidentally
 Plastic or metal and have different size
and shape openings
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Scales
Instruments used to lay off distances and
make measurements
 Full size or some proportion
 Scaled.
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Architect’s scale
Inch Scale
 Divided into proportional feet’ and inches”
 Used for drawing buildings
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Mechanical Engineer’s scale
Inches and fractions of an inch divided to
represent inches
 Use for drawing machine parts
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Civil Engineer’s scale
Inches divided into decimals
 Units could be inch, feet, miles etc
 Used for maps and drawings of roads
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