- Understanding Solid Objects
- Understanding Sketching Techniques
- 3.1 Technique of Lines
- 3.2 Sketching Straight Lines
- 3.3 Sketching Circles, Arcs, and Ellipses
- 3.4 Maintaining Proportions
- 3.5 One-View Drawings
- 3.6 Pictorial Sketching
- 3.7 Projection Methods
- 3.8 Axonometric Projection
- 3.9 Isometric Projection
- 3.10 Isometric Drawings
- 3.11 Making an Isometric Drawing
- 3.12 Offset Location Measurements
- 3.13 Hidden Lines and Centerlines
- 3.14 Angles in Isometric
- 3.15 Irregular Objects
- 3.16 Curves in Isometric
- 3.17 True Ellipses in Isometric
- 3.18 Orienting Ellipses in Isometric Drawings
- 3.19 Drawing Isometric Cylinders
- 3.20 Screw Threads in Isometric
- 3.21 Arcs in Isometric
- 3.22 spheres in Isometric
- 3.23 Oblique Sketches
- 3.24 Length of Receding Lines
- 3.25 Choice of Position in Oblique Drawings
- 3.26 Ellipses for Oblique Drawings
- 3.27 Angles in Oblique Projection
- 3.28 Sketching Assemblies
- 3.29 Sketching Perspectives
- 3.30 Curves and Circles in Perspective
- 3.31 Shading
- 3.32 Computer Graphics
- 3.33 Drawing on Drawing
- Key Words
- Chapter Summary
- Review Questions
- Sketching Exercises
Sketching is a quick way of visualizing and solving a drawing problem. It is an effective way of communicating with all members of the design team.
Three-dimensional figures are bounded by surfaces that are either planar, single-curved, double-curved, or warped.
Prisms, pyramids, cylinders, cones, tori, and ellipsoids are common shapes in engineering drawings. There are also five regular polyhedra: the tetrahedron, hexahedron, octahedron, dodecahedron, and icosahedron.
There are special techniques for sketching lines, circles, and arcs. These techniques should be practiced so they become second nature.
Using a grid makes sketching in proportion an easy task.
Circles can be sketched by constructing a square and locating the four tangent points where the circle touches the square.
A sketched line does not need to look like a CAD or mechanical line. The main distinction between CAD and instrumental drawing and freehand sketching is the character or technique of the line work.
Freehand sketches are made to proportion, but not necessarily to a particular scale.
Sketching is one of the most important skills for accurately recording ideas.
Isometric, oblique, and perspective are three methods used to create pictorial sketches.