Technical Free Hand Sketching

1
Technical Free Hand Sketching

• Leon Grant

2
Essential Question

• Why is free hand sketching still such an
  important tool for engineers with the abundance
  of CAD programs?
• GPS ENGR-IED-6 Students will create technical
  freehand sketches.
• a. Demonstrate orthographic, pictorial,
  schematic, and diagram sketches.

3
Proper Sketching Techniques

• Read text
• Class Demonstration
• Basic Sketching Exercises
• Have students work on basic line drawing skills
  (horizontal, vertical, incline, curve)
• Use Grid paper initially as a guide
• Work on sketching consistency
• Gradually work on speed (this exercise is not a
  race to finish but an exercise to develop
  fundamental skills)
• Use exercise to develop fundamental skills

4
Construction Lines
5
Sketch Squares Triangles
Vary Size Vary Orientation
6
Rectangles Circles
Vary shape Use Construction lines for circles
7
Add Hatching
Add Hatching to shapes. Focus on lines being
parallel, with consistent line weight and spacing
8
Sketch Basic Shapes without Grid Paper
9
Alphabet of Lines

• Review Alphabet of lines
• Line type weight
• Purpose of each line type

10
Introduce Geometric Construction

• Vertical, horizontal, diagonal and curved lines
  are the basic elements used to construct
  geometric shapes such as pentagons, stars,
  ellipses, etc.
• Geometric construction ensures the proper steps
  are followed using construction lines and visible
  lines to create geometric shapes.
• Steps should be followed to increase student
  proficiency.
• Once proficiency is established some steps can be
  combined or skipped.

11
General Procedures

1. Establish part axis
2. Establish units maintain proper aspect ratio
3. Use construction lines to create shape
4. Correct and retrace shape with visible lines

12
Example of Ellipse
Construction Line
Step 1. Use construction lines to create the
horizontal vertical Axis. Mark off
proportional units Note hand sketches are not to
scale the units sizes are arbitrary but
consistent maintaining the proper aspect ratio.
6 units
Step 2. Use construction lines to box in the
shape.
12 units
Visible Line
Step 3. Use construction lines to create shape.
Correct or retrace construction lines with
visible lines.
ASPECT RATIO WIDTHHEIGHT
126
21 (Reduced)
13
Sketching Problem

1. Construct horizontal and vertical axis with
   consistent units.
2. Box in shape maintaining proper aspect ratio.
3. Utilize proper construction technique to sketch
   parts or part elements.
4. Correct or retrace construction lines with
   visible lines.

14
Sketching Assignment

• Assign 10-15 sketching problems
• Sketch 5 without grid paper
• Sketch 5 with grid paper
• Sketch 5 with grid paper to ½ double scale.