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					ENGR 2160 - Engineering Graphics

       Working Drawings

      Chapter 12 (Bethune)
  and other reference materials
HOW DOES EVERYTHING COME TOGETHER?
   We’ve made our drawings.
      Orthographic, Auxiliary, etc.

   We’ve dimensioned out drawings
   We’ve indicated tolerances in our drawings.
   Etc.

   So what’s next ?
   Let’s briefly understand various terms used in
    Engineering Drawings
       Assembly, parts list, blocks ….
WORKING OR ASSEMBLY DRAWINGS
   In this chapter we will talk about assembly drawings.
   We will talk briefly about guidelines for titles,
    revisions, tolerances and release blocks.
WORKING DRAWINGS OR CONSTRUCTION
DRAWINGS
   Working drawings
    are a set of
    assembly and
    detail drawing
   These drawings
    are given to
    contractors to
    perform work or
    manufacture
    individual parts
   These drawings
    are legal
    documents
ASSEMBLY DRAWINGS
   Different type of assembly drawings include:
     Design  assemblies, or layouts
     General assemblies
     Detail assemblies
     Working drawing assemblies
     Outline or installation assemblies
     Inseparable assemblies (weldments, etc.)
ASSEMBLY DRAWINGS
   These drawings are sometimes called top drawings because
    they are the first of a series of drawings used to define a group
    of parts that are to be assembled together.
      The group of drawings are referred to as a family of
       drawings and may include subassemblies, modification
       drawings, detail drawings and parts list.
   Views should show how the parts fit together and suggest
    function of the unit
   A sectional view maybe used to show internal areas critical to
    the assembly.
   Hidden lines are typically not needed
   Assembly drawings are usually not dimensioned
ASSEMBLY DRAWINGS
DETAIL DRAWINGS

 Detail drawings contain all of the necessary
  information to manufacture a part
 Detail drawings are also called:
     Piece part drawings
     Part drawings
DETAIL DRAWINGS
IDENTIFICATION

 Each part of the assembly is identified by an
  assembly or item, number. These numbers are
  enclosed in a circle or ellipse.
 Use circled numbers called balloon numbers or
  ball tags to identify parts in an assembly
 Circles are placed in orderly horizontal or
  vertical rows and not scattered over the sheet
IDENTIFICATION
DRAWING TEMPLATES

 AutoCAD includes many different drawing
  templates that conform to ANSI and ISO
  standards.
 These templates automatically include:
     Drawing   border
     Title block

     Revision block

     A partial release block
DRAWING TEMPLATES – BORDER & BLOCK

   Drawing Border
     File -> New -> Tutorial-iMfg
     File -> New -> Tutorial-mMfg

   Edit block
     Explode   block first
DRAWING TEMPLATES – REVISION BLOCK

   Revision Block
     Drawings   in industry are constantly being changed.
      Products are improved or corrected, and drawings
      must be changed to reflect and document these
      changes.
     Each drawing revised is listed by letter in the
      revision block. The revision letter is also added to
      the field of the drawing in the area where the
      change was made.
DRAWING TEMPLATES – TOLERANCE BLOCK

   Tolerance block is placed next to the title block
    and lists the standard tolerances that apply to
    the dimensions on the drawing.
DRAWING TEMPLATES – RELEASE BLOCK
   A release block contains a list of approval signatures or initials
    required before a drawing can be released for production.
   The required signatures are:
      Drawn

      Checked

      Design

      Stress/Wts.

      Materials

      Customer
    DRAWING TEMPLATES – RELEASE BLOCK
   Drawn – The person that created the drawing
   Checked – Drawings are checked for errors and compliance with
    company procedures and conventions. Some companies have
    checking department others have a senior person or the drafting
    supervisor
   Design- The engineer in charge of the design project. The designer
    and the drafter maybe the same person
   Stress/Wts – Department or the person responsible for the design.
   Materials- person in the production department who checks the
    design and makes sure that the necessary materials and machine
    times for the design are available. This person may also schedule
    production time.
   Customer – The customer for the design may have a representative
    on site at the production facility to check that its design requirement
    are met.
PARTS LISTS

   A parts list or bill of materials (BOM) typically
    contains:
     Partidentification number (PIN)
     Description of each part

     Quantity required in the assembly
        Abbreviationscan be used to indicate quantities that are
         not known such as AR (as required) and EST (estimated
         quantity)
PARTS LIST
CLASS EXERCISE

 Open EX 9-1
 Create Title Block, Release, Revision and
  Tolerance Blocks. Refer to Figure 12-23 (page
  493)
 Tolerance of part 1 has changed from +/-.05 to
  +/-.07
    DETAIL DRAWINGS
   A detail drawing is a drawing of a single part.
   The drawing should include all the information necessary to
    accurately manufacture the part including:
       Orthographic views
       Dimensions
       Tolerances
       Material requirements
       And any manufacturing requirements.
   Detail drawings include the following in the same places they
    are found in the assembly drawings.:
      Title

      Release

      Tolerance

      And Revision Blocks
    DRAWING NOTES
   These notes are used to provide manufacturing information
    that is not visual, for example:
      finishing instructions

      torque requirements for bolts

      and shopping instructions.

   These notes are usually located above the title block on the
    right side of the drawing.
   These notes are listed by number.
   If the note applies to a specific part of the drawing, the note
    number is enclosed in a triangle.
      These numbers (enclosed in triangles) are also drawn next
        to the corresponding areas of the drawing.
    DESIGN LAYOUTS
   A Design Layout is not a drawing.
   This is like a visual calculation sheet used to size and locate
    parts of a design developed.
   A design layout allows you to build the assembly on paper.
   When drawings are created on a drawing board an initial layout
    is made locating and sizing the parts. Then the individual detail
    drawings and the assembly drawing are traced from the layout.
       This is done in AutoCAD using the “Layer” command.
CLASS EXERCISE

   Read Sample Problem SP 12-1 (Page 496). DO
    NOT DO THE DRAWINGS
End of Chapter - 12

				
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