Sketching & Drawing Projects Unit 18

Objectives Describe the difference between a sketch and a drawing and explain the different type of drawings. Describe the procedures used to make mechanical drawings. Properly letter drawings and sketches Draw and sketch different views of objects Read and interpret plan drawing Prepare a bill of materials from a sketch or plan drawing

Introduction Why?????? Represent the shapes and sizes of objects Aids in developing functional ideas on paper. Aids in construction and repairs according specifications Reduces the amount time, money, and materials needed for a project. Aids in without the use of expert assistance

Sketches & Drawings Sketches Simply Rough outline of an object Can be made freehand or a straightedge Not drawn to scale Sketches of small, simple projects with proper dimensions can be sufficient

Sketches & Drawings Drawings Requires scaled drawing Made with drawing instruments Pencil and ink are used Usually ink over pencil for plans kept for long periods.

Pictorial Drawing Pictorial drawings shows all three dimensions at once

Symbols Border line – a heavy, solid line drawn parallel to the edges of the drawing paper. Object line – a solid heavy line, less than border lines, showing visible edges and form of an object. Hidden line – a series of dashes that indicates or shows the hidden features of a part. Dimension line – a solid line with arrowheads at the ends to indicate the length, width, or height of an object or part.

Symbols Extension line – a solid line showing the exact area specified by a dimension. Break line – a solid, zigsag line used to show the illustration stops but the object does not. Center line – a long-short-long line used to indicate the center of a round object. Leader line – a solid line with an arrow used with an explanatory note to point to a specific feature of an object.

How to Sketch a Horizontal Line 1st – mark off two points spaced a distance equal to the length of the line to be drawn. Points should be parallel to the top or bottom of the page. . .

How to Sketch a Horizontal Line 2nd –Move your pencil back and forth and connect these points with a construction line. 3rd –Start from left point and sketch an object line to the right point. This line is sketched over the construction line.

How to Sketch a Vertical Line 1st – mark off two points spaced a distance equal to the length of the line to be drawn. Points should be parallel to the left or right side of the page. 2nd –Move your pencil back and forth and connect these points with a construction line.

How to Sketch a Vertical Line 3rd –Start from left point and sketch an object line to the right point. This line is sketched over the construction line.

How to Sketch an Inclined Line 1st –Mark off two points at the desired angle. Connect these points with a construction line. 2nd—Sketch the desired weight line over the construction line. Sketch up when the lines inclines to the right. Sketch down when the line inclines to the left.

How to Sketch Squares & Rectangle See handout.

How to Sketch Angles See handouts.

How to Sketch Circles See Handout.

How to Sketch an Arc See handout

How to Sketch an Ellipse See handout

How to Sketch a Hexagon See handout

How to Sketch an Octagon See Handout.

Scale Drawing Scale is the size of a plan or drawing as compared to that of the object it represent.

Types of Drawings Orthographic drawings Pictorial drawings

Orthographic Drawings Shows separate views of an object Top Front End or side These views are referred to as working drawings

Pictorial Drawings Two basic types – isometric & oblique Shows three views of the object together which resembles a picture of the object to be made

Orthographic Views

Pictorial View .

Mechanical Drawing Equipment Drawing Board 20” X 26” softwood, free of knots Accommodate 17” x 22” paper Left and right edges of the board must be straight

Triangles 45 degree triangles 30-60-90 degree triangles

Isometric Drawing Three views to transfer to an object top front side

THE BOX top front side