COACHING-KEY-TO-PASS PDF

Alphabet of Lines Section lines are completely enclosed by a boundary of visible lines. Enclosing section lines defines the cut area of a drawing. Arrows on a cutting plane line indicate the direction of line of sight. Arrows show where the observer is looking for the sec...

Alphabet of Lines Section lines are completely enclosed by a boundary of visible lines. Enclosing section lines defines the cut area of a drawing. Arrows on a cutting plane line indicate the direction of line of sight. Arrows show where the observer is looking for the section view. Use capital letters at the ends of the cutting-plane line to help the drawing's reader match each cutting-plane line to its corresponding section view. Capital letters identify and connect section views to the cutting planes. Orthographic Drawing Section views can replace the normal top, front, side, or other standard orthographic views in the standard view arrangement. Replacing views simplifies the presentation of complex details. Primary auxiliary view is projected from any of the three orthographic views. Auxiliary views display inclined surfaces not visible in standard views. The auxiliary plane is assumed parallel to the inclined surface, and the line of sight is always perpendicular to it. Parallel auxiliary planes ensure accurate shape depiction. The worm's eye view produces a perspective that shows the object as though looking up from below, typically emphasizing the underside of the object. Worm's eye views highlight the bottom of the object. Reference lines - Drawings do not show the planes of the glass box; however, these planes are represented by reference lines. Reference lines are used to organize orthographic projections. Isometric Drawing Isometric drawings have equal foreshortening along each of the three axis directions. Equal foreshortening creates uniform 3D representation. Dimetric drawings have equal foreshortening along two of the three axes, with the third axis foreshortened differently. Uneven foreshortening emphasizes specific axes. In isometric drawings, hidden and center lines are typically omitted. Omitting hidden lines reduces clutter in 3D drawings. Dimetric - This type of axonometric drawing has equal foreshortening along two axis directions and a different amount on the third axis. Dimetric drawings highlight differences between axes. Nonisometric lines - Lines of an isometric drawing that are not parallel to the isometric axes are called nonisometric lines. Nonisometric lines represent features not aligned to the axes.  120 degrees - The angle between each axis for an isometric drawing is 120 degrees. Equal angles provide accurate isometric proportions. Box method - For isometric drawings, rectangular objects are drawn using the box method. The box method defines object proportions within a framework. Auxiliary Drawing Auxiliary views are often used to produce views that show all of the above. Auxiliary views provide true size and shape of inclined features. Auxiliary views are drawn to show the true size and shape of the inclined surface. Inclined surfaces appear undistorted in auxiliary views. An auxiliary in section - is an auxiliary section. Auxiliary sections combine sectional and auxiliary projections. Ellipses - Circles, when perpendicular to the plane of projections, normally appear as ellipses in auxiliary views. Circular shapes become elliptical due to projection angles. Sectional Drawing When the part is cut fully in half, the resulting view is called a full section. Full sections expose the entire interior of a part. The term "section lines" is the same as "hatching" (a term meaning closely spaced parallel lines). Section lines highlight the cut portion of the object. Extension lines and dimension values should not be placed directly on sectioned areas, as they can obscure details and make the drawing less readable. Dimensioning outside sectioned areas improves clarity. A removed section is one that is not in direct projection from the view containing the cutting plane. Removed sections are placed elsewhere to avoid overlapping. Broken-out sections are used to expose only a small, localized part of the interior shape, not the entire interior. They are limited by a break line to show specific internal details. Broken-out sections reveal specific internal features. Broken-out section - This type of section is limited by a break line. Break lines define the boundary of localized sections. Removed section - This type of section is not in direct projection from the view containing the cutting plane. Removed sections isolate views for clarity. 90 degrees - In offset sections, offsets or bends in the cutting plane are all 90 degrees. Perpendicular offsets simplify complex cuts. Long breaks - These breaks are used to shorten the view of an object. Long breaks eliminate repetitive details for clarity.  Full section - When a part is cut fully in half, the resulting view is called a full section. Full sections show complete internal structure. Capital letters - Cutting planes are labeled with capital letters. Labels link cutting planes to corresponding sections. Half section - This type of section is used to represent section views when an object is symmetric. Half sections balance detail with simplicity. Offset section - Complex objects that have several features to describe are normally described with offset sections. Offset sections adjust the cutting plane to capture features. Oblique Drawing When the receding lines are drawn to half size, the drawing is known as a cabinet projection. Cabinet projections minimize depth distortion. Cavalier projection - When the receding lines are true length and the projectors are at 45 degrees to the plane of projection, the oblique drawing is called cavalier projection. Cavalier projections emphasize full-depth representation. Isometric drawings - Oblique drawings are dimensioned in a similar fashion as isometric drawings. Oblique drawings follow similar measurement rules as isometric ones. Perspective Drawing The term isometric means "equal angles." Equal angles ensure uniformity in the isometric view. The position of the observer's eye is called the station point. The station point determines the view's perspective. One-point perspective is not known as angular perspective. Instead, angular perspective refers to two-point perspective, where two vanishing points are used to depict depth and dimension. Angular perspectives use two points for realistic depth. Shading pictorial drawings help clarify the shapes of objects by emphasizing light and shadow, making the 3D form more understandable. Proper shading enhances clarity rather than causing confusion. Shading highlights contours and details. Perspective drawings are classified according to their number of vanishing points. The number of vanishing points determines the depth effect. Perspectives are the most realistic-looking of the pictorial drawing styles. Perspective styles closely resemble natural human vision.  The bird's eye view produces a perspective view that shows the object as though looking down from above, providing a top-down perspective. Bird's eye views offer a comprehensive overview of objects. Perspective drawings are often the most time-consuming types of pictorials to draw by hand due to the complexity of establishing vanishing points and accurately representing depth. Perspective drawings require careful attention to depth. Vanishing points - Perspective drawings are classified according to their number of vanishing points. Vanishing points guide the convergence of lines in depth. Angular perspective - Two-point perspective is also known as angular perspective. Angular perspective provides depth with two vanishing points. Station point - In perspective drawings, the position of the observer's eye is called the station point. The station point establishes the view’s focal point. Architectural design - Historically, perspective drawings are used more for architectural design. Architectural perspective illustrates spatial arrangements. Good luck and God bless, everyone! Remember that you have given your best effort throughout the semester, and everything will fall into place as it should. Trust in the process and the work you’ve put in. Keep believing in yourselves, and no matter the outcome of your examination, know that your dedication and perseverance are what truly count. You've grown and learned so much—be proud of how far you've come. Best, Sir Ran