Page 117 - Engineering drawing from first principles using AutoCAD

Chapter ~

Text and dimensions

This chapter introduces you to:

• Text types and editing options.
• Special characters.
• Overscoring and underscoring.
• Dimensioning principles.
• Functional and Auxiliary dimensions.
• Toleranced dimensions.
• The selection of limits and fits from ISO tables with shaft and hole combinations.
• Combining characters to produce limits and fits for use on drawings.

Text

There are many different fonts available in CAD but BS 308 favours types which are open
form and free from serifs and embellishments. Capital letters are preferred. Vertical or
sloping letters are acceptable but for ease of application the vertical form is the most
convenient for CAD. It is not acceptable to mix styles. Examples are shown in Fig. 5.1.

To be consistent, all the text on the drawings in this book has been added using the
Roman Duplex style. Select Roman Duplex from the Text Style dialogue box in the
Settings menu and click OK. Various text options are now available at the command line
as follows.

Height <0.000>: Enter 3.5.
Width factor <1.000>: Enter 0.9.
Obliquing angle <0>: OK.
Backwards ?<N>: OK.
Upside down ?<N>: OK.
Vertical ?<N>: OK.

(a) ABCDEFGHIJKLMNOPQRSTUVWXYZ
abc d efg h ij kim n 0 p q r st u v w x y z
1234567890

(b) A8CDEFGHIJKLMNOPQRSTUVWXYZ
ob cdefghijklmnopqrstuvwxyz
~/234S67890

(c) ABCOEFGHIJKLMNOPQRSTUVWXYZ
aabcdefghijklmnopqrstuvwxyz
1234567890

(d) ABCOEF6HIJKLMNOPQRSTUVWXYZ
aabcdefghijklmnopqrstuvwxyz
1234567890
Figure 5.1