Engineering 111.txt

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Engineering 111.txt
2012-09-26 17:48:35
Exam Texas

Flash Cards for ENGR 111 Track A
Show Answers:

  1. Full section
    - Cutting plane passes throug entire object
  2. Offset Section
    Cutting plane bent at 90 degress to show more detail on asymmetrical objects
  3. Half Section
    • - Removes a quarter of the object
    • - Reveals half of its internal details
    • - All hidden lines ommitted
    • - Not necessary to label cutting plane
    • - Only half of view is cross sectioned
  4. Revolved Section
    - Shows cross-section by rotating 90 degrees

    - Remains on object
  5. Removed Section
    - Shows cross section by rotating 90 degrees

    - Moved to the side of object
  6. Broken out section
    - No cutting plane required

    - Does not modify rest of view
  7. Broken View
    - Used for extremely large or long objects

    - 2 break lines
  8. Detailed View
    -Circle cut out showing more detail of an object

    -Must have scale
  9. Sectioned Pictorials
    Sketch of the object with portion missing
  10. Do NOT Hatch!!!
    • Ribs
    • Thin parts like gaskets
    • Shafts or pins
    • Screws or nuts
  11. Cast Iron and General Use
    ANSI 31
  12. Steel
    - "striped"

    - ANSI 32
  13. Brass, Bronze, Copper
    -ANSI 33

  14. Lead, Zinc, Magnesium
    -ANSI 37
  15. Aluminum
    ANSI 38
  16. Crest
    Peak or prominent point of a thread
  17. Root
    Bottom point at which sides of a thread meet
  18. Flank
    Thread surface that connects a crest and a root
  19. Angle
    Degrees between two flanks
  20. Pitch
    Distance between 2 adjacent crests or 2 adjacent roots
  21. Thread length
    Length of a threaded portion of a shaft
  22. Depth
    Height of a crest
  23. Shank
    Unthreaded portion between head and threads
  24. Thread symbols
    Detailed, schematic, simplified
  25. Knurl
    Pattern cut into cylindrical parts to improve gripping
  26. Counterbored
    CBORE or CB
  27. Spotfaced
    SFACE or SF
  28. Countersunk
    CSINK or CSK
  29. Counterdrilled
    CDRILL or CD
  30. Diameter
  31. Depth
  32. What is the standard measurement of an engineers's scale?
  33. What is the standard measurement of a metric scale?
  34. How does an architect's scale work?
    Number on left of equal sign is specified by some fraction of an inch, number on the right is ALWAYS 1'-0"

    Ex. 1/2 = 1'0"
  35. Tolerance
    -Range of acceptable values for a particular dimension

    -The smaller the tolerance, the higher the cost of manufacturing
  36. General Tolerance
    -Applies to all dimensions of a drawing

    -Often found in title block

    -Normally in bilateral form
  37. Limit form - Tolerance
    Has max value over min value
  38. Unilateral form - Tolerances
    Has base value, then to the right of it has the maximum added above mimimum added
  39. Bilateral form - Tolerances
    Base diameter, then to the right it has +/- a number
  40. Linear Fit Tolerances
    How tight or how loose moving and sliding parts wll fit
  41. Hole tolerance
    LPH - SPH

    - Determines cost of hole
  42. Shaft Tolerance
    LPS - SPS

    - Determines cost of shaft
  43. Allowance
    SPH - LPS

    -Tightest fit between two moving parts

    -Does not affect cost of parts
  44. Maximum Clearance
    LPH - SPS

    -Loosest fit between parts

    -Does not affect cost of parts
  45. Clearance Fit
    Shaft is always smaller than hole
  46. Line fit
    Shaft is either smaller or equal to hole
  47. Transition fit
    -Shaft could be larger or smaller than hole

    -Cheapest way to manufacture part
  48. Which fit is the cheapest to manufacture a part?
    Transition fit
  49. Interference fit
    -"Force fit"

    -shaft always larger than hole
  50. Geometric tolerances
    -Controls level of error of shape not size
  51. Dimensioning
    Always in real world units

    Do not put units by numbers
  52. Styles for dimensioning
    - Unidirectional: dimensions face same direction

    - Alligned: dimensions parallel to lines
  53. Dimension spacing
    - First row: 3 letter heights away (3/8")

    - Successive rows: 2 lettee heights away (1/4")
  54. Dimensioning Cylinders
    Place diameter where it appears at a rectangle
  55. Bolt circle
    When feature has repetitive holes in circular pattern

  56. Repetitive features
    Ex. .75 DIA - 4 HOLES
  57. Horizontal projection plane
    -Top view

    -Depth and width
  58. Frontal projection plane
    -Front view

    -Height and width
  59. Profile projection plane
    -Side view

    -Height and depth
  60. Which dimensions on an orthographic projection project directly?
    Height and width
  61. What is the difference between pictorials and orthographic projections?
    Orthographic projections use 2-D views to represent an object. Projection pictorials show all three directions of space in one picture
  62. Parallel projections
    Any lines that are parallel in the object are parallel in views
  63. Perspective projections
    Reproduce the effect that distant objects appear smaller than nearer objects. Lines which are parallel in nature converge towards a single point.
  64. Types of axonometric projections
    • Isometric
    • Dimetric
    • Trimetric
  65. Isometric projection
    • -All three angles equal 120 degrees
    • -H, W, and D are true size along isometric axes
    • -Angles must be located by coordinates
    • -Circles appear as ellipses on all surfaces
  66. Dimetric projection
    2 angles are equal
  67. Trimetric
    All 3 angles are different
  68. Oblique projection
    Most descriptive face of object is projected parallel to projection plane, thus appearing true size
  69. Cavalier oblique
    • -Front view true shape and size
    • -Receding axis angle normally 30, 45, 60 degrees
    • -Depth dimension true size
  70. Cabinet oblique
    • -Front view true shape and size
    • -Receding axis angle normally 30, 45, 60 degrees
    • -Depth dimension HALF size
  71. General oblique
    • -Front view true shape and size
    • -Receding axis angle normally 30, 45, 60 degrees
    • -Depth dimension is BETWEEN full and half size
  72. GRID Command

    Just a visual aid, does not print
  73. SNAP Command

    Allows you to specify precise coordinates when using the mouse
  74. ORTHO Command
    Allows you to only draw in the vertical or horizontal direction
  75. DDEDIT Command
    Click on a text or dimension to be edited/changed
  76. BHATCH command

    Area must be closed
  77. How many views are required to illustrate an object?
    • -Depends on the object
    • -The minimum necessary to adequately show the object's geometry
  78. What is the thickest line drawn in an orthographic drawing?
    Visible line
  79. Which view should be the most descriptive view?
    Front view
  80. Which dimension should be minimized in orthographic views?
  81. What are drawing methods used to provide a clearer understanding of an object, even if orthographic rules are violated?
    Conventional practices
  82. Which type of sketch is not a pictorial?
  83. What types of projections are not parallel projections?
  84. In what type of oblique drawing is depth represented true size?
  85. Auxiliary view
    Used to represent the true size and shape of objects with sloping surfaces
  86. In English thread notes, what represents the fit
    • 1 for loose
    • 2 for regular
    • 3 tight
  87. In English thread notes, what represents if the thread is internal or external?
    • A is external
    • B is internal
  88. In metric thread notes, what represents the tolerance?
    Numbers ranging from 3-9. The larger the number, the larger the tolerance.
  89. In metric thread notes, what represents the fit?
    • Letters.
    • E - loose fit
    • G - regular fit
    • H - tight fit
    • Lowercase letters mean external
  90. In metric thread notes, what represents the thread length?
    • S - short
    • N - normal
    • L - long
  91. T or F: The force on a truss link is called an axial force
  92. How do you calculate the number of joints in a 2-D truss?
    L = 2 • J - 3
  93. How do you calculate the number of joints in a 3-D truss?
    L = 3 • J - 6
  94. What are allowable loads (working loads)?
    Forces to which the links can be safely subjected.
  95. What are the two principle modes of failure?
    Failure by separation and failure by deflection.
  96. True or False. Zero-force members cannot improve the strength of a truss
  97. How do you calculate arc length?
    S=R•radian angle
  98. How do you find zero force truss members.
    If a joint connects only two truss members and no support reaction or external force is applied to the joint

    If a joint connects only three members and two of the members are co-linear, and no support or external force is applied, then the non co-linear member is a Zero force member
  99. In which views will circles appear as ellipses for all views?
    Axonometric projections
  100. What determines the diameter of the spotface for a spotface hole?
    Left to the disgression of the machinist
  101. In what type of sections can you show hidden lines?
    Broken out sections
  102. How do you calculate a safe loads?
    • External load Largest tensile
    • Force
    • --------------= --------------
    • Max allowable Tensile External load strength
  103. How do you calculate the factor of safety?
    • Failure level Strength
    • ------------- = --------------
    • actual Internal Level member force
  104. T or F: The factor of safety is the most conservative value?
  105. When calculating internal forces, what do we assume?
    The the bars are in tension. Therefore, the arrows are drawn going away from joint