Sketching (Freehand) • Sketching is a method of visualizing and conceptualizing your ideas that will allow you to communicate your ideas to others. • Sketching is not intended to produced final engineering drawings, but it is an important step in the engineering design process.
Sketching Pencils • Pencils come with leads of varying degrees of hardness. • Hard grades H – 4H • Soft grades B – 4B • HB = #2 Pencil • The larger the number the harder of softer the lead.
Understanding Sketching Techniques • Analyzing complex objects • The ability to break down complex shapes into simpler geometric primitives is an essential skill for sketching and modeling objects • Basic curves and straight lines are the basis of many objects
Understanding Sketching Techniques • Maintaining Proportions – It is very important to keep the sketch in proportion • It is beneficial to block out general proportions using construction lines.
Understanding Sketching Techniques • Essential shapes can be blocked in using construction lines • Proportions are also maintained
Sketching Lines • Straight Lines • Angle Paper • Swing from elbow and not wrist • Draw in one fluid stroke • Experiment with direction
Sketching Objects (3D) • Viewpoint • You should always maintain the same viewpoint when sketching an object. • Isometric Sketching • When sketching 3D objects it is easiest to choose a viewpoint that will produce an isometric sketch.
Basic Structure of Objects • Cube or Rectangular Solid • Cylinder • Cone / Pyramid • Sphere • Combination of the above
Geometric Constructions • We are going to cover five basic geometric constructions that will be useful in drawing. • Bisect an angle • Bisecting a line using a compass. • Draw a perpendicular to a line at a point. • Finding the center of a circle • Dividing a line into n equal segments