© 2012, 2009, 2003, pearson higher education, upper saddle
TRANSCRIPT
1Technical Drawing with Engineering Graphics, 14/e
Giesecke, Hill, Spencer, Dygdon, Novak, Lockhart, Goodman
© 2012, 2009, 2003, Pearson Higher Education,
Upper Saddle River, NJ 07458. • All Rights Reserved.
C H A P T E R T H R E E
TECHNICAL
SKETCHING
3Technical Drawing with Engineering Graphics, 14/e
Giesecke, Hill, Spencer, Dygdon, Novak, Lockhart, Goodman
© 2012, 2009, 2003, Pearson Higher Education,
Upper Saddle River, NJ 07458. • All Rights Reserved.
Understanding Solid Objects-Types of Solids. Pg 62The way to beak down the object into parts that make you to draw each one easier with having all the required dimensions to comply your design. Considering relationship between parts and keep in mind the straight lines and basic curves are the basic of many objects.
Understanding Sketching Techniques-Analyzing Complex Objects. Pg 64-Points & Lines Pg 67-Angles Pg 68Before going through the free hand sketching we need to know all the Technique of drafting, concepts, how to Design object and learning how to draw those:-Points-Lines-Angled lines-Arcs-Circles & Ellipse.*Use the basic shapes as a guide to place key features. See Guitar example Pg64
4Technical Drawing with Engineering Graphics, 14/e
Giesecke, Hill, Spencer, Dygdon, Novak, Lockhart, Goodman
© 2012, 2009, 2003, Pearson Higher Education,
Upper Saddle River, NJ 07458. • All Rights Reserved.
5Technical Drawing with Engineering Graphics, 14/e
Giesecke, Hill, Spencer, Dygdon, Novak, Lockhart, Goodman
© 2012, 2009, 2003, Pearson Higher Education,
Upper Saddle River, NJ 07458. • All Rights Reserved.
CHAPTER OVERVIEW
The ability to envision three dimensional objects is an important skill for
scientist, engineers, designers, technicians and students. Learning to visualize
objects takes time and practice. Students must learn by studying technical
drawings and applying these concepts to practical applications. People who are
extraordinarily creative often posses outstanding abilities to visualize but with
practice anyone can approve their ability.
Sketching allows individuals to quickly and accurately communicate ideas.
The old saying a picture is worth a thousand words, is really true. Sketching is
an efficient way to plan your drawing and record notes needed to create a
complex object.Sketches and drawings are used to communicate or record ideas
about the shape of 3D objects.
Shaded Sketch Showing Details of Wire Placement. (Courtesy of Quantum Design.)
6Technical Drawing with Engineering Graphics, 14/e
Giesecke, Hill, Spencer, Dygdon, Novak, Lockhart, Goodman
© 2012, 2009, 2003, Pearson Higher Education,
Upper Saddle River, NJ 07458. • All Rights Reserved.
UNDERSTANDING SOLID OBJECTS
Three-dimensional figures are referred to as solids. Solids are
bounded by the surfaces that contain them. These surfaces
can be one of the following four Basic types:
• Planar
• Single curved
• Double curved
• Warped
Regardless of how complex a solid
may be, it is composed of combinations
of these basic types of surfaces.
Basic geometric shapes of solids are: prisms,
pyramids, cylinders, cones, spheres, tori, or ellipsoids. All three
dimensional objects are comprised of one or more of these
basic geometric shapes.
*Keep your shapes basic and simple.
7Technical Drawing with Engineering Graphics, 14/e
Giesecke, Hill, Spencer, Dygdon, Novak, Lockhart, Goodman
© 2012, 2009, 2003, Pearson Higher Education,
Upper Saddle River, NJ 07458. • All Rights Reserved.
Types of Solids
If the faces of a solid are equal regular polygons, it is called a regular polyhedron.
There are 5 regular polyhedron:
Solids that are bounded by plane surfaces are called as polyhedra, Pg 62-63
These Planar surfaces are also referred to as faces of the object.
- A polygon is a planar area that is enclosed by straight lines.
8Technical Drawing with Engineering Graphics, 14/e
Giesecke, Hill, Spencer, Dygdon, Novak, Lockhart, Goodman
© 2012, 2009, 2003, Pearson Higher Education,
Upper Saddle River, NJ 07458. • All Rights Reserved.
Prisms
A prism has two bases,
which are parallel equal
polygons, and three or
more additional faces,
which are parallelograms
9Technical Drawing with Engineering Graphics, 14/e
Giesecke, Hill, Spencer, Dygdon, Novak, Lockhart, Goodman
© 2012, 2009, 2003, Pearson Higher Education,
Upper Saddle River, NJ 07458. • All Rights Reserved.
Pyramids
A pyramid has a polygon for a base and triangular lateral
faces that intersect at a common point called the vertex.
10Technical Drawing with Engineering Graphics, 14/e
Giesecke, Hill, Spencer, Dygdon, Novak, Lockhart, Goodman
© 2012, 2009, 2003, Pearson Higher Education,
Upper Saddle River, NJ 07458. • All Rights Reserved.
Cylinders & Cones
A cylinder has a single-
curved exterior surface
A cone has a single-
curved exterior
surface
11Technical Drawing with Engineering Graphics, 14/e
Giesecke, Hill, Spencer, Dygdon, Novak, Lockhart, Goodman
© 2012, 2009, 2003, Pearson Higher Education,
Upper Saddle River, NJ 07458. • All Rights Reserved.
Spheres, Tori & Ellipsoids
A sphere has a double-
curved exterior surface
A torus is shaped like
a doughnut
An oblate or prolate
ellipsoid is shaped like an
egg
12Technical Drawing with Engineering Graphics, 14/e
Giesecke, Hill, Spencer, Dygdon, Novak, Lockhart, Goodman
© 2012, 2009, 2003, Pearson Higher Education,
Upper Saddle River, NJ 07458. • All Rights Reserved.
Viewpoint and Shading
Viewpoint: As you sketch objects, keep in mind that
you want to maintain a consistent viewpoint, like a
camera does.
Easiest sketching is when you convert object from a
book. There’s no other views will be for the object( you
can’t move around object., but you move around object
we have a multiple view point which is different and
depends on where you stand. See the rubber stand on
side as example.
Adding shading to your sketch can give it a more
realistic appearance because it represents the
way the actual object would reflect
light. And that could helps us to have idea
material type is using of object. Such as
aluminum, steel or Iron
Hatching and stippling
13Technical Drawing with Engineering Graphics, 14/e
Giesecke, Hill, Spencer, Dygdon, Novak, Lockhart, Goodman
© 2012, 2009, 2003, Pearson Higher Education,
Upper Saddle River, NJ 07458. • All Rights Reserved.
Edges and Vertices
EdgesAn edge of the solid is formed where two
surfaces intersect. Edges are represented in
drawings by visible or hidden lines depends
on view points.
VerticesA vertex (plural, vertices) of a solid is
formed where three or more surfaces
intersect.
Points and LinesA point is used to represent a location in space
but has no width, height, or depth.
14Technical Drawing with Engineering Graphics, 14/e
Giesecke, Hill, Spencer, Dygdon, Novak, Lockhart, Goodman
© 2012, 2009, 2003, Pearson Higher Education,
Upper Saddle River, NJ 07458. • All Rights Reserved.