# Engineering 111 flashcards.txt

 Full section - Cutting plane passes throug entire object Offset Section Cutting plane bent at 90 degress to show more detail on asymmetrical objects 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 Revolved Section - Shows cross-section by rotating 90 degrees - Remains on object Removed Section - Shows cross section by rotating 90 degrees - Moved to the side of object Broken out section - No cutting plane required - Does not modify rest of view Broken View - Used for extremely large or long objects - 2 break lines Detailed View -Circle cut out showing more detail of an object -Must have scale Sectioned Pictorials Sketch of the object with portion missing Do NOT Hatch!!! RibsThin parts like gasketsShafts or pinsScrews or nuts Cast Iron and General Use ANSI 31 Steel - "striped" - ANSI 32 Brass, Bronze, Copper -ANSI 33 -"Road" Lead, Zinc, Magnesium -ANSI 37 Aluminum ANSI 38 Crest Peak or prominent point of a thread Root Bottom point at which sides of a thread meet Flank Thread surface that connects a crest and a root Angle Degrees between two flanks Pitch Distance between 2 adjacent crests or 2 adjacent roots Thread length Length of a threaded portion of a shaft Depth Height of a crest Shank Unthreaded portion between head and threads Thread symbols Detailed, schematic, simplified Knurl Pattern cut into cylindrical parts to improve gripping Counterbored CBORE or CB Spotfaced SFACE or SF Countersunk CSINK or CSK Counterdrilled CDRILL or CD Diameter DIA Depth DP What is the standard measurement of an engineers's scale? Inches What is the standard measurement of a metric scale? Millimeter 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" Tolerance -Range of acceptable values for a particular dimension -The smaller the tolerance, the higher the cost of manufacturing General Tolerance -Applies to all dimensions of a drawing -Often found in title block -Normally in bilateral form Limit form - Tolerance Has max value over min value Unilateral form - Tolerances Has base value, then to the right of it has the maximum added above mimimum added Bilateral form - Tolerances Base diameter, then to the right it has +/- a number Linear Fit Tolerances How tight or how loose moving and sliding parts wll fit Hole tolerance LPH - SPH - Determines cost of hole Shaft Tolerance LPS - SPS - Determines cost of shaft Allowance SPH - LPS -Tightest fit between two moving parts -Does not affect cost of parts Maximum Clearance LPH - SPS -Loosest fit between parts -Does not affect cost of parts Clearance Fit Shaft is always smaller than hole Line fit Shaft is either smaller or equal to hole Transition fit -Shaft could be larger or smaller than hole -Cheapest way to manufacture part Which fit is the cheapest to manufacture a part? Transition fit Interference fit -"Force fit" -shaft always larger than hole Geometric tolerances -Controls level of error of shape not size Dimensioning Always in real world units Do not put units by numbers Styles for dimensioning - Unidirectional: dimensions face same direction - Alligned: dimensions parallel to lines Dimension spacing - First row: 3 letter heights away (3/8") - Successive rows: 2 lettee heights away (1/4") Dimensioning Cylinders Place diameter where it appears at a rectangle Bolt circle When feature has repetitive holes in circular pattern BC Repetitive features Ex. .75 DIA - 4 HOLES Horizontal projection plane -Top view -Depth and width Frontal projection plane -Front view -Height and width Profile projection plane -Side view -Height and depth Which dimensions on an orthographic projection project directly? Height and width 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 Parallel projections Any lines that are parallel in the object are parallel in views Perspective projections Reproduce the effect that distant objects appear smaller than nearer objects. Lines which are parallel in nature converge towards a single point. Types of axonometric projections IsometricDimetricTrimetric 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 Dimetric projection 2 angles are equal Trimetric All 3 angles are different Oblique projection Most descriptive face of object is projected parallel to projection plane, thus appearing true size Cavalier oblique -Front view true shape and size-Receding axis angle normally 30, 45, 60 degrees-Depth dimension true size Cabinet oblique -Front view true shape and size-Receding axis angle normally 30, 45, 60 degrees-Depth dimension HALF size General oblique -Front view true shape and size-Receding axis angle normally 30, 45, 60 degrees-Depth dimension is BETWEEN full and half size GRID Command F7 Just a visual aid, does not print SNAP Command F9 Allows you to specify precise coordinates when using the mouse ORTHO Command Allows you to only draw in the vertical or horizontal direction DDEDIT Command Click on a text or dimension to be edited/changed BHATCH command Crosshatching Area must be closed How many views are required to illustrate an object? -Depends on the object-The minimum necessary to adequately show the object's geometry What is the thickest line drawn in an orthographic drawing? Visible line Which view should be the most descriptive view? Front view Which dimension should be minimized in orthographic views? Depth What are drawing methods used to provide a clearer understanding of an object, even if orthographic rules are violated? Conventional practices Which type of sketch is not a pictorial? Multi-view What types of projections are not parallel projections? Perspectives In what type of oblique drawing is depth represented true size? Cavalier Auxiliary view Used to represent the true size and shape of objects with sloping surfaces In English thread notes, what represents the fit 1 for loose2 for regular3 tight In English thread notes, what represents if the thread is internal or external? A is externalB is internal In metric thread notes, what represents the tolerance? Numbers ranging from 3-9. The larger the number, the larger the tolerance. In metric thread notes, what represents the fit? Letters.E - loose fitG - regular fitH - tight fitLowercase letters mean external In metric thread notes, what represents the thread length? S - shortN - normalL - long T or F: The force on a truss link is called an axial force True How do you calculate the number of joints in a 2-D truss? L = 2 • J - 3 How do you calculate the number of joints in a 3-D truss? L = 3 • J - 6 What are allowable loads (working loads)? Forces to which the links can be safely subjected. What are the two principle modes of failure? Failure by separation and failure by deflection. True or False. Zero-force members cannot improve the strength of a truss False How do you calculate arc length? S=R•radian angle 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 In which views will circles appear as ellipses for all views? Axonometric projections What determines the diameter of the spotface for a spotface hole? Left to the disgression of the machinist In what type of sections can you show hidden lines? Broken out sections How do you calculate a safe loads? External load Largest tensile Force--------------= --------------Max allowable Tensile External load strength How do you calculate the factor of safety? Failure level Strength------------- = --------------actual Internal Level member force T or F: The factor of safety is the most conservative value? True When calculating internal forces, what do we assume? The the bars are in tension. Therefore, the arrows are drawn going away from joint AuthorAnonymous ID52758 Card SetEngineering 111 flashcards.txt DescriptionEngineering 111 Track A Updated2010-12-02T01:40:44Z Show Answers