IED - Unit 2 - Lesson 2.3 Advanced Modeling Skills

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Assembly Drawings, Balloons, and Parts Lists
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Working Drawings
A design that has been approved for prototype or
full-scale manufacture requires a set of working
drawings to communicate the objects geometry to
everyone involved with its manufacture and
assembly. Working drawings are a complete set of
documents that include

• Individual part drawings
• One or more assembly drawings
• A parts list

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Assembly Drawings
An assembly drawing shows how all of the parts of
a multi-component design fit together, and are
generally depicted as one or more orthographic
projections. One or more full section views are
often used in an assembly drawing to show
necessary internal features.
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Example Assembly Drawing
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Information from Assemblies
Assembly drawings may contain the following

• One or more views, including sections or
  auxiliaries
• Enlarged views to show small details
• Overall or specific dimensions needed for
  assembly
• Notes on manufacturing processes required for
  assembly
• Balloons to indicate item numbers
• Parts list or bill of materials (BOM)

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Types of Assembly Drawings

• Design Assembly
• General Assembly
• Detail Assembly
• Erection Assembly
• Subassembly
• Pictorial Assembly

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Design Assembly
Design assemblies are used to show various
relationships between components. The design
assembly at the right shows the kinematic
relationship that exists between the fly wheels
360 rotation, and the extreme angular motion of
the piston cylinder body.
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Design Assembly
Design assemblies are often made from sketches
during the preliminary phases of a design process
to study the relationships that exist between the
components before the design is modeled.
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General Assembly
A general assembly is the most common type of
assembly drawing. It is displayed as a multiview
drawing and may contain a section view. General
assemblies do not contain dimensions.
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Detail Assembly
A detail assembly is a combination of an assembly
view with several of its parts depicted as
dimensioned multiview drawings on one drawing
sheet. This practice, though not common, reduces
the number of drawing sheets needed, and is more
appropriate for designs with small numbers of
components.
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Example Detail Assembly
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Erection Assembly

• Similar to general assemblies, except dimensions
  and fabrication specifications are commonly
  included.
• Typically associated with cabinetry or products
  that are made from structural steel.
• Used for both fabrication and assembly.

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Subassembly Drawing
Flashlight Subassembly
Complex or large assemblies may be communicated
through subassembly drawings.
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Pictorial Assembly

• Usually depicted as an isometric or perspective
  drawing.
• May be rendered to imitate photographic quality.
• Uses include

- Sales promotion - Customer self-assembly -
Maintenance procedures
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Pictorial Assembly Drawings
Pictorial assemblies are often used in catalogs,
journal articles, and advertisements. This
pictorial is sectioned to show interior details.
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Pictorial Assembly Drawings
Exploded pictorial assembly drawings are commonly
used to show how individual components fit
together.
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Balloons
A balloon is a circle that contains a single
number, which is connected to an assembly
component with a leader line.
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Balloon Guidelines

• All balloons on a drawing should be the same
  size.
• Balloons should be grouped together in an easy-
  to-read pattern.
• Balloon numbers must correspond to item numbers
  in a parts list.
• Balloons should not have horizontal or vertical
  leader lines.

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Parts List
A parts list is a table that contains information
about each of the parts contained in an assembly.
The item numbers correspond with the balloon
numbers.
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Example Parts List
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Parts List Information
Items commonly found in a parts list include

• Item number from balloons.
• Quantity the number of a particular part needed
  for the assembly.
• Part or drawing number a reference back to the
  detail drawing.
• Description usually the part name or complete
  description of a purchase part.
• Material identification the material of the
  part.
• Information about vendors for purchase parts.

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Parts List Location
The location of a parts list usually depends on
company standards. Common locations include

• Above the title block most common
• Upper right corner
• Upper left corner
• A convenient location on the drawing

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Parts List Location