Dimensioning a Drawing
Dimensioning a drawing is perhaps the most important step in creating a
technical drawing. Dimensions allow you to accurately convey information on your design to
the reader. As you begin to dimension your drawing, you will find they are only as
accurate as the drawing you create. Properly set up and applied, AutoCAD can allow you to
easily and accurately dimension your drawings.
The objectives of this assignment are:
- Understand dimensions and their use. In
this unit you will look at the majority of the AutoCAD dimensioning commands. You will
begin by covering some basic dimensioning terminology. While the placement of dimensions
is very important, it is beyond the scope of this course to describe how to properly
dimension a drawing. Both the ANSI and AIA provide commercial standards for dimensioning.
It is important that you learn any standards necessary in your particular discipline and
apply them to the AutoCAD dimensioning commands.
- Understand the importance of associative dimensioning.
By default all dimensions you create in AutoCAD are considered associative. This
means that all objects that make up the dimension are grouped into one object. This has
many advantages, and some disadvantages as well.
- Create and use dimension styles and families. Dimensions
styles and families are a way you can save specific dimensions settings.
- Modify existing dimensions. One very
important point to remember when dimensioning a drawing with AutoCAD is just because
AutoCAD created a dimension in a specific manner, it does not mean it is correct. Often
you will have to modify a dimension, or even create a dimension manually (draw separate
lines, arrows, text, etc.)
- Create oblique dimensions and leader. These
are two types of dimensions commonly used in AutoCAD for dimensioning.
- Read Unit 13,
Dimensioning a Drawing. This
unit was intentionally written in a generic format - not geared specifically toward any
one discipline. In the optional assignments you will have the opportunity to create
specific dimensions styles and apply apply them to mechanical and architectural drawings.
- Complete Tutorial 13.1 - 13.3. In this set
of tutorials you will open up a sample drawing, and work with several of the dimensions
- Complete Tutorial 13.4 - 13.8. In these
tutorials you will apply different types of dimensions to the sample drawing.
- Complete Tutorial 13.9. Here you will
modify a dimension, and add a leader.
- Unit 13 tests from the
Testing Website. Complete the
following tests and E-MAIL me the results.
- Unit Review. Ten multiple choice questions over the chapter
- Command Review. Ten multiple choice questions covering
- Essay Exam. Five questions about dimensioning.
||Remember that just because AutoCAD creates a dimension a particular way
does not mean it is correct. You still need to know proper dimensioning practices. Does
AutoCAD dimensioning help, or does it make it too easy to create incorrect dimensions? Post
a question or comment on this unit in the forum.
What to Turn In:
E-MAIL me the following:
- The completed DIMENSION.DWG file from tutorials 13.1 - 13.8.
In the optional architectural assignment, set up a
dimension style specifically for architectural drawings. You will then use this style to
dimension the floor plan you have been working on in the past several units.
Dimension the Floor Plan
The optional mechanical assignment creates two dimension
styles, one for US Customary units, and the other for Metric (SI) units. You will then
apply these dimension styles to the metric Micro Stop and the Worm Gear which you created
in the previous units.
Dimension the Micro Stop.
Dimension the Worm Gear.
The optional electrical assignment you will download and
dimension two different drawings. One drawing uses the US Customary units, and the other
Metric (SI) units. After downloading and dimensioning these drawings, E-MAIL them.
Dimension the Circuit Board Mount.
Dimension the C-CLAMP.