A. Alphabet of Linesa. Dimension Lines -A line used to define the measurement of a part feature. Dimensionlines consist of a solid line with arrows at both ends and a dimension in the center. b. Extension Lines - A line used to visually connect the ends of a dimension line to therelevant feature on the part. Extension lines are solid and are drawn perpendicular tothe dimension line. c. Guide Lines ²d. Arrow Headse. Figure lines / object lines - A line used to define the shape and size of a part feature. Objectlines are solid. f. Projection lines - used to indicate the extremities of a dimension. They aregenerally drawn up to 1 mm from the outline of the object. g. M iter linesh. Broken lines / hidden lines - A line used to define a part feature that is not visible in aspecific view. Hidden lines consist of a series of short dashes. i. Section lines - A line used to identify the imagined cut portion of a part in a section view.Section lines appear as a series of diagonal lines drawn close together. j. Angle indicatork. Radius limel. Cutting plane line - A line used to define the location of the imaginary cut that creates thematching section view. Cutting plane lines consist of two short dashes alternating with a longerdash. m. Phantom line - consist of long dashes separated by pairs of shortdashes.The long dashes may vary in length, depending on the size of the drawing. Phantom lines show alternate positions of related parts,adjacent positions of related parts, and repeated detail. n. Construction line -o. Leader line - A thin line with an arrow head that is often positioned at an angle and is used totie a dimension to a feature, especially when there are space limitations. p. B. Isometric view - a method for visually representing three-dimensional objects in two dimensionsintechnicalandengineering drawings. It is anaxonometric projectionin which thethreecoordinate axesappear equally foreshortened and the angles between any two of them are120 degrees. C. Orthographic view - Orthographic projection (or orthogonal projection ) is a means of representing athree-dimensionalobject intwo dimensions. It is a form of parallel projection,where all the projection lines areorthogonalto the projection plane, [1] resulting in every plane of the scene appearing inaffine transformationon the viewing surface. D. Axonometric view - Ax onometric projection is a type of parallel projection, more specifically atype of orthographic projection, used to create a pictorial drawing of an object, where the object isrotated along one or more of its axes relative to the plane of projection. E. Auxiliary View - A view drawn at a right angle to an angled feature of the part. Auxiliary views bestillustrate angled surfaces. F. Perspectivea. Bird·s eye viewb. Worm·s eye viewc. Eye leve
Posted on: Thu, 18 Jul 2013 04:23:08 +0000