ch.4 engineering geometry & construction
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Ch.4 Engineering Geometry & Construction . Geometric construction and engineering geometry (4.1) Coordinate spaces (4.3) Geometric elements (4.4) Points, lines, surfaces & solids (4.5) Conic curves (4.6). - PowerPoint PPT PresentationTRANSCRIPT
Ch.4 Engineering Geometry & Construction
Geometric construction and engineering geometry (4.1)
Coordinate spaces (4.3) Geometric elements (4.4) Points, lines, surfaces & solids (4.5) Conic curves (4.6)
We cannot cover all materials in this chapter in one lecture. Some of the definitions and concepts have been covered in your education up to this point (from elementary school). We place emphasis on quickly constructing necessary geometric elements. Terms you learn from this chapter have direct relevance to CAD.
Geometric construction and engineering geometry
Geometric construction Act of constructing a geometry, especially using hand tools.
Dividing a line Cylinder
Engineering geometry Basic geometric elements and forms used in engineering design.
Engineering geometry classified Manual
drafting AutoCAD
Coordinate space 2-D Cartesian coordinate system
Coordinate space (cont.) 3-D coordinate system
Coordinate space (cont.)
Right-hand rule for axes direction & positive direction of rotation on each axis Note that counter clockwise is positive (default positive rotation of ACAD)
Coordinate space (cont.) Polar coordinates, Cylindrical coordinates, & Spherical
coordinates
Points, lines, circles, and arcs In this lecture we focus on geometric
construction techniques that are needed to do manual drafting assignments.
Dividing a line into equal parts (4.5.2)
Points, lines, circles, and arcs (cont.)
Constructing arcs tangent to two lines (4.5.3)
Points, lines, circles, and arcs (cont.)
Constructing an arc tangent to a line and another arc
Points, lines, circles, and arcs (cont.) Constructing an arc tangent to two given arcs or circles
Points, lines, circles, and arcs (cont.)
Constructing an arc tangent to two given arcs
Points, lines, circles, and arcs (cont.)
Constructing an arc tangent to a given arc
Points, lines, circles, and arcs (cont.)
Constructing lines tangent to two circles o arcs, using a straightedge (a trial and error method)
Conic curves : parabolas
Focus
Conic curves : Ellipses
Conic curves : Ellipses (cont.)
Conic curves : Ellipses (cont.)