Technical Free Hand Sketching Leon Grant

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.

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

Construction Lines

Sketch Squares & Triangles Vary Size Vary Orientation

Rectangles & Circles Vary shape Use Construction lines for circles

Add Hatching Add Hatching to shapes. Focus on lines being parallel, with consistent line weight and spacing

Sketch Basic Shapes without Grid Paper

Alphabet of Lines Review Alphabet of lines Line type & weight Purpose of each line type

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.

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

Example of Ellipse 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. Step 2. Use construction lines to box in the shape. Step 3. Use construction lines to create shape. Correct or retrace construction lines with visible lines. 12 units 6 units ASPECT RATIO = WIDTH:HEIGHT 12:6 2:1 (Reduced) Construction Line Visible Line

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.

Sketching Assignment Assign sketching problems Sketch 5 without grid paper Sketch 5 with grid paper Sketch 5 with grid paper to ½ & double scale.