- 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
- Worksheets
- Review Questions
- Sketching Exercises
3.28 Sketching Assemblies
Assembly drawings are used to show how parts fit together. Because they do not need to provide all the information to make individual parts, isometric sketches or drawings are often used that show only the exterior view of the assembled parts. You can use assembly sketches as you design to identify areas that must fit together or have common dimensions, or to maintain critical distances to ensure that the device will function as expected. Figure 3.66 shows an isometric sketch of an assembly.
3.66 Isometric Assembly Sketch
Sketched assembly drawings are useful in documenting your ideas in a rougher state. An exploded isometric assembly drawing shows the individual parts moved apart from one another along the isometric axis line directions. A centerline pattern is used to show how the parts relate and fit together.
When creating an exploded assembly sketch, keep the parts lined up with the other parts where they assemble. If possible, move any single parts along only one axis direction. In Figure 3.67, all exploded parts are moved along only one axis direction. Notice the centerline pattern showing how the parts align. If you must move a part in two different directions so that it can be seen clearly, add a centerline showing how the part must move to get to its proper location in the assembly. In Figure 3.68, parts have been moved in two axis directions. You can see the jog in the centerline indicating how the part has been moved.
3.67 Exploded Isometric Assembly Sketch. Centerlines have been added to show where parts line up in the assembly.
3.68 Isometric Assembly Sketch. Some parts have been exploded in two directions so they do not overlap other parts in the assembly. The centerlines indicate the path the part must follow to assemble correctly. (Courtesy of Albert W. Brown, Jr.)
Finished assembly drawings that will be given to manufacturing workers to show them how to produce a device also contain a parts list that identifies each part in the assembly, the quantity necessary, the material of each part, and a number identifying which item it is on the drawing. A parts list can also be included on a sketched assembly drawing. Sometimes it is helpful to give a quick assembly sketch to manufacturing along with part drawings, especially if they are parts you need to have manufactured quickly from a sketch. Seeing how the parts fit together in assembly will help the manufacturer understand the entire device and identify potential problems.