CAD CAM Unit 2 - 2D Drafting

1. UNIT II – 2D DRAFTING
CME340 – CAD/CAM
Mr.M.Mani
AP-MECH

2. UNIT II – 2D DRAFTING
Projection views Orthographic view, Axillary view, Full
& Half Section views, Broken Section view, Offset
Section view Title Block creation BOM Creation Notes
creation Ballooning of 2D drawing and its features for
Inspection reporting
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3. Projection views
Projection views refer to different perspectives or representations of an
object or a scene that are created by projecting it onto a two-
dimensional surface. These views are commonly used in fields such as
engineering, architecture, and design to communicate complex
information effectively.
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4. Projection views
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5. Projection views
In technical drawing, projection views are used to represent three-
dimensional objects on a two-dimensional plane, typically using orthogonal
projections. Orthographic projection is a technique that involves projecting
the object onto three mutually perpendicular planes: the front view (also
known as the elevation view), the top view (plan view), and the side view
(profile view). These views provide a comprehensive understanding of the
object's shape, dimensions, and features from different directions.
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7. • Each projection view shows specific details and
characteristics of the object. The front view displays the
object's frontal features and represents its height and width,
the top view represents the object's footprint and
demonstrates its length and width, while the side view
illustrates the object's depth and shows additional features
that may not be visible in the front or top views. By
combining these views, a more complete representation of
the object can be achieved.
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9. • Projection views are also used in computer-aided design (CAD)
software to create digital representations of objects. These software
programs allow users to manipulate and view objects from different
angles and perspectives, helping in the design process and facilitating
communication among designers, engineers, and other stakeholders.
• In summary, projection views are different perspectives or
representations of an object created by projecting it onto a two-
dimensional plane. They are commonly used in technical drawing and
CAD software to communicate complex information about the
object's shape, dimensions, and features from different directions.
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10. Auxiliary view
• An auxiliary view is a type of projection view used in technical
drawing to represent the true shape and size of an object's inclined or
oblique surface. It is an additional view that provides a more accurate
representation of the object by showing the inclined surface in its
true shape and size, rather than its distorted appearance in the
primary orthographic views.
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12. • When an object has surfaces that are not parallel to any of the primary
planes (front, top, or right side views), the true shape and size of those
surfaces cannot be accurately shown in the orthographic views. This is
where auxiliary views come into play. An auxiliary view is created by
projecting the inclined surface onto a plane that is perpendicular to
the inclined surface. This projection results in a view that represents
the inclined surface in its true shape and size.
• Here are the key characteristics and uses of auxiliary views:
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13. Perpendicularity: The auxiliary view is created by
projecting the inclined surface onto a plane that is
perpendicular to that surface. This ensures that the
resulting view accurately represents the shape and size
of the inclined surface.
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14. • Line of Sight: The auxiliary view is drawn by projecting lines
from points on the inclined surface onto the perpendicular
plane. These lines represent the line of sight from the
primary view to the inclined surface.
• Angle of Projection: The angle at which the lines of sight are
projected onto the perpendicular plane determines the
shape and size of the auxiliary view. It is important to choose
the appropriate angle of projection to accurately represent
the inclined surface.
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15. • Visualizing Hidden Features: Auxiliary views are particularly useful in
showing hidden features or details of an object that are not visible in
the primary views. By providing an additional perspective, auxiliary
views enhance the understanding of the object's geometry and aid in
design and manufacturing processes.
• Placement: Auxiliary views are typically placed adjacent to the
primary views, aligning them with the corresponding inclined
surfaces. This arrangement allows for easy visualization and
comparison between the primary views and the auxiliary view.
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16. • Auxiliary views are commonly used in engineering, architecture, and
manufacturing to accurately represent complex geometries, inclined
surfaces, and irregular shapes. They provide a valuable tool for
visualizing and communicating the true shape and size of objects,
especially when the primary orthographic views are insufficient to
convey all the necessary information.
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17. FULL SECTION VIEW
• A full section view is a type of drawing that displays an object or
structure as if it has been cut completely in half and one half has
been removed to reveal the internal details. This view is commonly
used in technical drawings, engineering designs, and architectural
plans to communicate the internal features, dimensions, and
relationships of components within the object or structure. Here's a
detailed explanation of the concept, applications, and benefits of full
section views:
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19. Concept
In a full section view, a cutting plane is used to slice through the object
or structure, creating a clean break. The sectioned part is then
removed, allowing the viewer to see the internal features that would
otherwise be hidden. The cut surface is typically represented by a
dashed line with arrows indicating the direction of the section view.
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20. Applications:
•Engineering Design
•Architecture
•Maintenance and Repair
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21. Benefits:
• Clarity and Communication
• Visualization
• Dimensional Information
• Cost and Time Savings
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22. Half section view
• A half section view, also known as a half-cut view, is a type of drawing
that displays an object or structure as if it has been cut in half,
revealing the internal details on one side while still maintaining the
external shape on the other side. Here's a detailed explanation of half
section views, their applications, and benefits:
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23. • Concept:
• In a half section view, a cutting plane is used to slice through the
object or structure, dividing it into two halves. One half is left intact
and represented in its full shape, while the other half is sectioned to
expose the internal features. The cut surface is typically represented
by a dashed line with arrows indicating the direction of the section
view.
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24. Applications
• Symmetrical Objects
• Simplified Representation
• Highlighting Specific Areas
• Combination with Other Views
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25. Benefits
• Clear Visualization
• Simplified Representation
• Focus on Specific Details
• Efficient Communication
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26. • A broken section view, also known as a revolved section view or offset
section view, is a type of drawing that represents the internal features
of an object or structure by breaking away a portion of it and
displacing it to one side. This technique is used when a traditional full
or half section view does not provide a clear representation of the
internal features due to space constraints or overlapping
components. Here's a detailed explanation of broken section views,
their applications, and benefits:
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27. Concept
• In a broken section view, a portion of the object or structure is cut
and then offset or displaced to one side of the drawing. This
displacement allows the internal features to be revealed without
overlapping with other components or obstructing the view. The cut
surfaces are typically represented by diagonal lines or jagged lines,
indicating the broken or displaced section.
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29. Applications
• Complex Internal Structures
• Large Assemblies
• Clearance Verification
• Combination with Other Views
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30. Benefits
• Improved Clarity
• Highlighting Specific Details
• Space Efficiency
• Effective Communication
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31. • An offset section view, also known as an offset section or offset
cutting plane, is a technique used in technical drawing to represent
the internal features of an object or structure when a traditional
straight section view is not sufficient or practical.
• In an offset section view, the cutting plane is shifted or offset from
the typical straight-line path to avoid overlapping or obscuring
important features. This allows for a clearer representation of the
internal details without compromising the overall understanding of
the object or structure.
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32. Offset section view
• The offset section view is typically indicated by a cutting plane line
with an offset dimension or arrow indicating the direction and
magnitude of the offset. The resulting sectioned view shows the
object as if it has been cut along the offset cutting plane, revealing
the internal features in a modified position.
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34. The applications and benefits of offset section
views include
• Complex or Congested Geometry
• Interference Detection
• Clear Visualization
• Combined with Other Views
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35. Title Block creation
• A title block is a crucial component of a technical drawing that
provides essential information about the drawing and serves as a
standardized section for documentation. It typically appears in the
lower-right corner of the drawing sheet and includes important
details related to the drawing. Here's a step-by-step guide on creating
a title block in a technical drawing:
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36. • Determine the Required Information: Identify the necessary
information that needs to be included in the title block. This typically
includes details such as the drawing title, drawing number, revision
number, date, scale, company name or logo, project name, and
relevant contact information.
• Determine the Title Block Size: Determine the size and placement of
the title block based on the drawing sheet size and any specific
requirements or standards applicable to your industry or
organization. The title block should be positioned consistently on all
drawings for uniformity and easy identification.
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37. • Divide the Title Block: Divide the title block into distinct sections to
accommodate the different information elements. Common sections
include the drawing title, drawing number, revision block, project
information, scale, and dates. You may also include a space for
approvals or signatures if required.
• Design and Layout: Create a clear and organized layout for the title
block. Use lines, borders, and boxes to separate and distinguish each
section. Ensure that the text is legible, and choose an appropriate
font size and style. Align the information consistently within each
section.
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38. • Incorporate Company Logo and Graphics: If desired, include your
company logo or any relevant graphics in the title block. This helps to
establish branding and adds a professional touch to the drawing.
• Add Dynamic Fields: In modern CAD software or drawing software,
you can set up dynamic fields for elements such as the date, revision
number, and drawing number. These fields can automatically update
as the drawing is revised or as the date changes.
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39. • Test and Review: Before finalizing the title block, review it for
accuracy and completeness. Ensure that all necessary information is
included, and verify that the layout is clear and visually appealing.
Test the dynamic fields, if applicable, to ensure they update correctly.
• Incorporate the Title Block in Templates: Once the title block design is
finalized, save it as a template in your CAD software or drawing
software. This allows you to easily insert the title block into future
drawings, ensuring consistency across all drawings.
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40. • Remember to adhere to any industry or company-specific standards
or guidelines regarding the content and format of the title block.
These standards may vary depending on the field, project
requirements, or regulatory requirements.
• By following these steps and customizing the title block to suit your
specific needs, you can create a professional and informative title
block for your technical drawings.
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41. Bill of Materials
• BOM, or Bill of Materials, is a document that lists all the components,
parts, materials, and quantities required to build or assemble a
product. It is commonly used in technical drawings and engineering
documentation to provide a comprehensive and organized list of the
items needed for manufacturing or assembly. Here's a step-by-step
guide on creating a BOM in a technical drawing:
• Identify the Components: Review the technical drawing and identify
all the components that need to be included in the BOM. These
components can range from individual parts to subassemblies or even
complete products.
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45. • Create a Table: Open a new table or spreadsheet document to create
the BOM. Label the columns with the necessary headings, such as
Item Number, Part Number, Part Description, Quantity, Material, and
any other relevant information required for your specific project or
industry.
• Fill in the Information: Starting with the first component, enter the
details in each corresponding column of the BOM table. Assign a
unique item number or identifier to each component to maintain
consistency throughout the BOM.
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46. • Include Relevant Information: In addition to the basic information,
include any additional details that are pertinent to the components.
This may include specifications, dimensions, notes, reference
numbers, or any other relevant information that would aid in
accurately identifying and procuring the components.
• Determine Quantity: Determine the quantity of each component
required for the assembly or manufacturing process. Ensure that the
quantities listed in the BOM align with the design specifications and
any applicable industry standards.
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47. • Group Components: If your assembly consists of subassemblies or
multiple levels of components, group them accordingly in the BOM.
This helps to organize and provide a clear hierarchy of components,
making it easier to understand the structure of the product.
• Review and Verify: Once the BOM is complete, review and verify the
information for accuracy and completeness. Check for any missing or
duplicate entries, and ensure that the quantities and descriptions are
correct.
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48. • Update and Maintain: BOMs are dynamic documents that may need
to be updated as design changes or revisions occur. Establish a
process for maintaining and updating the BOM to reflect the most
current information. This ensures that the BOM remains accurate
throughout the manufacturing or assembly process.
• Incorporate BOM in Documentation: Incorporate the BOM into the
technical drawing or engineering documentation where it is required.
This could be as a separate page within the document or as an
attachment to the drawing.
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49. • By following these steps, you can create a well-structured and accu
rate BOM for your technical drawing. The BOM provides essential
information for manufacturing, procurement, and assembly
processes, helping to ensure the smooth and efficient production of
the designed product.
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50. NOTES CREATION
• Creating notes in technical drawings is an important aspect of
conveying information and specifications related to the drawing.
Notes provide additional details, instructions, and clarifications that
are necessary for understanding the drawing. Here are some
guidelines for creating notes in technical drawings:
• Placement: Notes should be placed close to the relevant feature or
dimension they are referring to. If there is limited space, notes can be
placed in the margins or in a designated notes section of the drawing.
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51. •
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53. • Clear and legible text: Use clear and legible text for the notes. It is
recommended to use capital letters for clarity, and avoid using cursive
or fancy fonts. Ensure that the text is of an appropriate size so that it
can be easily read.
• Consistency: Maintain consistency in the formatting and style of the
notes throughout the drawing. This includes using the same font, text
size, and text style (e.g., bold, italic) for all the notes.
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54. • Note structure: Begin each note with a capital letter and end with a
period (full stop). Keep the notes concise and to the point. If there is a
lot of information to convey, consider using bullet points or
numbered lists for better organization.
• Note callouts: When referring to specific features or dimensions in
the drawing, use callouts (leaders) to connect the note to the relevant
area. The callout line should point directly to the feature or
dimension being described.
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55. • Note content: The content of the notes should include important
information such as material specifications, tolerances, surface
finishes, assembly instructions, safety warnings, and any other
relevant details that cannot be adequately conveyed through the
drawing itself.
• Language: Use clear and precise language in the notes. Avoid
ambiguous or vague terms that could lead to misinterpretation.
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56. • Revision control: If revisions are made to the drawing, ensure that the notes are
updated accordingly. Indicate the revision level or date of the drawing to avoid
confusion.
• Proofreading: Always proofread the notes for spelling, grammar, and accuracy
before finalizing the drawing. Mistakes or unclear information in the notes can
lead to errors or confusion during manufacturing or assembly.
• Remember, the goal of notes in technical drawings is to provide clear and concise
information that complements the graphical representation. By following these
guidelines, you can create well-organized and informative notes that enhance the
understanding of the drawing for anyone who reads it.
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57. Ballooning
• Ballooning is a method used in inspection reporting to identify and
reference specific features or dimensions on a 2D drawing. It involves
adding numbered balloons or bubbles to the drawing, each corresponding
to a specific characteristic or item that needs to be inspected or measured.
These balloons serve as visual markers and are accompanied by a
corresponding inspection report or checklist that provides detailed
information about each numbered feature. Here are the key features and
steps involved in ballooning a 2D drawing for inspection reporting:
• Balloons: Balloons are circular or oval shapes containing a unique number
inside them. These balloons are typically placed adjacent to the feature or
dimension they refer to.
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58. •
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60. • Callout lines: Callout lines, also known as leader lines, connect the
balloons to the corresponding feature on the drawing. The callout
lines are typically drawn as straight lines with an arrow pointing
towards the feature.
• Numbering: Each balloon is assigned a unique number to differentiate
it from other balloons. The numbers are usually sequential and follow
a logical order, such as top to bottom or left to right.
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61. • Reference dimensions: Balloons are often used to reference specific
dimensions that need to be measured during inspection. The number
inside the balloon corresponds to the dimension in the inspection
report or checklist.
• Features and characteristics: Balloons can also be used to identify and
reference other features or characteristics on the drawing, such as
holes, fasteners, welds, surface finishes, or specific parts or
components.
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62. • Inspection report or checklist: Alongside the ballooned drawing, an inspection report or
checklist is created to provide detailed information about each numbered feature. The
report includes information such as inspection requirements, acceptance criteria,
measurement methods, and any specific instructions or notes related to the feature.
• Accuracy and clarity: It is essential to ensure that the balloons and callout lines are
accurately placed and clearly visible on the drawing. This helps to minimize confusion
and ensures that the inspector can easily identify and reference the desired features.
• Ballooning a 2D drawing provides a visual reference and simplifies the inspection process
by clearly identifying the features or dimensions to be inspected. It facilitates efficient
communication between the designer, inspector, and other stakeholders involved in the
inspection process, ensuring accurate and consistent reporting of inspection results.
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