2.00 Explain and demonstrate basic sketching skills and techniques.

2.01 Explain the concepts related to sketching. Sketching Concepts 2.01 Explain the concepts related to sketching.

Quickly & easily get an idea on paper Purpose of a Sketch Quickly & easily get an idea on paper Design sketches Freehand technical sketches Technical illustrations Most technical drawings start with a sketch

Freehand Technical Sketch

Design Sketch Leonardo Divinci sketch

Technical Illustration

Paper Pencil Optional Sketching Materials Soft lead Eraser Grid Paper Graph paper Isometric grid paper

Proportion Clarity Sketching Aids Sketching Technique Sketches must be proportional Use aids when sketching Pencil-sight sketching Pencil as a measuring device Keep your eye on the point to which you’re drawing

Vertical lines Long straight lines Sketching Lines Top to bottom Series of short straight lines Use edge of plain paper as an aid to the eye for keeping lines straight Move your entire arm Don’t draw from your wrist

Sketching Circles & Arcs Begin by lightly constructing a square Add center marks to square Draw

Begin with 90° angle Sketching Angles Subdivide once Subdivide twice 45° 60° 30° Subdivide once Subdivide twice

Sketching Assignment

Sketching 2.02 Explain the concepts and principles underlying isometric, oblique and multiview sketching.

Sketching Types of Sketches Single-view Multi-view Pictorials

Single-view Sketching Technical purposes Front view Most descriptive features

Steps for Single-view Sketching Object Step 2 Step 1 Step 3 Step 4

Multi-view Sketching Technical sketch Front view Top view Side view

Multi-view Sketch TOP VIEW FRONT VIEW R. SIDE VIEW

Single-view/Multiview Sketch Assignment

Quickly communicate an idea Three dimensions in one view Pictorial Sketches Quickly communicate an idea Three dimensions in one view Width Height Depth

Pictorial Sketches Three (3) types Isometric Oblique Perspective

Isometric Sketch HEIGHT WIDTH DEPTH

Three equally spaced axes of 120° Isometric Sketching The prefix “iso” means equal. Other positions are possible depending on what surfaces of the object are being emphasized Ellipses must be oriented according to the plane in which they appear Three equally spaced axes of 120°

Isometric Sketching Receding lines Typically 30° off horizontal

Isometric Sketching Circular shapes appear as ellipses

Isometric Ellipses Correct ellipse orientation

Non-Isometric lines Isometric Sketching Locate endpoints and connect You can measure along “isometric lines” You cannot measure along “non-isometric lines” A standard angle measuring device such as a protractor cannot be used to measure angles in isometric Angles are drawn by locating their end points

Oblique Sketch HEIGHT DEPTH WIDTH

Front view is drawn true shape and size Oblique Sketching Front view is drawn true shape and size Front view is normal to the viewer’s line of sight Circles and curves appearing on the side and top planes will be distorted Receding edges can be sketched at any angle except vertical or horizontal Long side of an object, circles, and arcs should be shown in the frontal plane to lessen distortion

Oblique Sketching Receding edges are usually drawn at an angle of 30°, 45°, or 60°

Oblique Sketching Circles and curves drawn on frontal plane will appear true shape and size

Perspective Sketches 1-Point Perspective 2-Point Perspective

Perspective Sketches Objects appear as the eye would see them Most realistic type of pictorial sketch Most difficult pictorial sketch to draw