Working Drawings - Engineering Design Graphics - Lecture Slides, Slides of Computer-Aided Design for Engineers

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Working

Drawings-

Standard Borders

• Almost All Engineering Firms Have Some Standard/Default Elements That are Included in all Engineering Drawings
• These Elements are incorporated into Standard “Borders & Title-Blocks” - When you First Go to Work for a Design Firm find the standard “Border” or “Frame” and make sure you understand the meanings of the all the elements

Anatomy of a Working Dwg

Rev. Block

Note Block

Zone No.

Zone Ltr.

On-Dwg BoM

FOIA Disclaimer^ Title Block

Note Indicator

BoM BallTag

Anatomy of a Working Dwg

Section/View Line

Zone Block

Detail Bubble

Separate-Sheet Parts List

Zoning & Reving

Zone 7B (or B7)

Notes & Comments - 1

• Revisions Must be Carefully Documented; Especially if they affect - Form (physical Shape) - Fit (mounting, or interface locations) - Function (how it works)
• Zoning on Sections & Details is Optional for 1 or 2 sheet drawings
• Rev’s should be Zoned UnLess meaning is “obvious”

Drawing SCALE Interpretation

• Typical Scale CallOut

SCALE 1:

Length On DRAWING

Length in REAL WORLD

• Example: Length In REAL WORLD = 73.75”

DW G RW

DW G

RW in in

in

in 4. 61

73. 75 × =

Architect/CE Scale Example

• Recall Scale Definition

X = Y

Size on DRAWING

Size in REAL WORLD

 Example - Given Scale: 2” = 1’-0”

• Drawing Size → (^) Scaling UP Find 6 "DWG

3 'RW − 0 "RW

Drawing SCALE Alternative

• Some Other Common Scale CallOuts

SCALE 1=10 or SCALE 1/

Length in REAL WORLD

Length On DRAWING

 Watkins-Johnson  Olympus

The Std Chabot Engr Dwg Frame

1st vs. 3rd Angle Projection

Projection Box (^) 1st-Ang. Note Front Surface is Projected BACKWARDS

1st Ang Proj

1st Angle (Europe)

FrontalFront V.Pln ProfileLside V.Pln

HorizontalTop Pln V.

HorizontalTop V. Pln

ProfileLside V.Pln FrontalFront V.Pln

3rd Angle USA, Asia

1 St^ Angle Projection

• The USA Conventionally Uses the So-Called “THIRD” Angle Projection Produced by Unfolding the “Glass Box”
• The European “FIRST” Angle Convention Essentially Projects the SHADOW of An Object Projected Onto a Screen BEHIND it.
• The 3rd Angle (USA type) Technique is Much More Intuititive

Who’s on First, I-Don’t-Know’s On Third (c.f. Abott & Costello)

“Third Angle Projection” Symbol Appears in Almost all Dwg Title Blocks

FIRST Angle Proj

THIRD Angle Proj

1 st^ & 3 rd^ Angles Summarized

 In FIRST-ANGLE projection, each view of the object is projected in the direction (sense) of sight of the object, onto the interior walls of the box

 In THIRD-ANGLE projection, each view of the object is projected opposite to the direction (sense) of sight, onto the (transparent) exterior walls of the box