Lettering and Dimensioning

1
Lettering and Dimensioning

• Unit 6
• Page 66

2
Objectives

• Read and produce Gothic style lettering.
• Follow guidelines of lettering.
• Produce letters with appropriate spacing.
• Identify different types of dimensions.
• Identify the proper placement of dimensions.

3
Lettering

• Most lettering on prints is of the Gothic style.
• Easy to read and construct.
• Gothic letters are constructed either vertically
  or inclined.

4
Lettering

• Vertical Gothic letters are mostly used on prints
  found in industry to indicate dimensions and
  notes.
• Inclined letters are used more for specific or
  special notes that need to stand out from the
  rest.

5
Forming Letters and Numerals

• Letters are formed by making certain strokes with
  your pencil.
• Figure 6-14 shows examples of the proper strokes
  you should take to make letters and numbers.

6
Forming Letters and Numbers

• Letters are usually made anywhere from 1/8 to 1/4
  inch in height.
• Numbers are made the same height as letters so
  everything looks uniform.

7
Guidelines

• When lettering, you can draw light horizontal or
  vertical guidelines to help get the proper height
  or width of the letters.
• When using the graph paper, use the 1/4 inch
  blocks as guidelines to create your letters and
  numbers for dimensions.

8
Spacing

• Spacing of letters should be pleasing to the eye.
• Dont crowd or leave too much space between
  letters and words.
• Letter spacing is at your discretion.

9
Dimensioning

• Dimensions provide the technical worker with the
  sizes of features of an object.
• There are 2 types of dimensions found on prints.
• 1. Size Dimensions
• 2. Location Dimensions

10
Size Dimensions

• Size dimensions tell how large or how small the
  features of a part are.
• Example The diameters of holes, the depth of a
  slot, or the width of an opening.

11
Location Dimensions

• Location dimensions tell the location of the
  features on an object.
• Example The center of a hole or the edge of a
  slot.

12
Dimension and Extension Lines

• Dimension lines are always parallel to the
  feature being dimensioned.
• Dimension lines always terminate with arrowheads
  at the ends.
• Must be straight lines.

13
Dimension and Extension Lines

• Extension lines show where a measurement or
  dimension starts and stops.
• Extend about 1/8 of an inch beyond the dimension
  line and have a 1/16 inch space between
  themselves and the object.
• Arrowheads should never extend past the extension
  lines on a print.

14
Placement of Dimensions

• There are 2 methods of placing dimensions on a
  print.
• 1. Unidirectional
• 2. Aligned

15
Unidirectional Dimensions

• Unidirectional dimensions are placed on a print
  so they can be read from the bottom of the
  drawing.
• These dimensions are easier to read because you
  dont have to rotate your paper to read them.

16
Aligned Dimensions

• Aligned dimensions are placed on a print so they
  can be read from the bottom or the side of the
  drawing.
• These dimensions are harder to read because you
  have to rotate your paper to read them.

17
Placement of Dimensions

• The unidirectional system is more common because
  the dimensions are easier to read.
• Only one of these systems should be used on a
  print at one time.
• Using both would make the prints harder to read.

18
Additional Things to Remember

• Whenever possible, all dimensions should be
  placed outside the views. This eliminates extra
  clutter on the part.
• Dimension between the views and beside the view
  where the feature is best described.
• Dimensions for narrow spaces or slots may be
  placed on the outside of the extension lines.

19
Summary

• Gothic letters should be made 1/8 to 1/4 inch in
  height.
• Use the lines of your graph paper as guidelines
  for lettering.
• Spacing should be pleasing to the eye.
• Dimension lines always terminate with arrowheads.

20
Summary

• Extension lines should have at least a 1/16 inch
  space between themselves and the object.
• Use unidirectional dimensioning.
• Place all dimensions outside the views to keep
  the part from becoming cluttered.

21
Assignment

• Complete the lettering exercises on vertical and
  inclined Gothic letters.