Drafting Equipment, Media, and Reproduction Methods CHAPTER 2 Drafting Equipment, Media, and Reproduction Methods

Learning Objectives Describe and demonstrate the use of manual drafting equipment and supplies Explain the concept of drawing scale, and identify common inch and metric scales Read metric, civil engineer, architect, and mechanical scales

Learning Objectives Describe and use drafting media, sheet sizes, and sheet blocks and symbols Explain common drawing reproduction methods

Manual Drafting (Hand Drafting) Mostly replaced by computer-aided design and drafting (CADD) Manual drafting and CADD require understanding the basics of drafting Scale Sheet size Sheet format

Manual Drafting Equipment and Supplies Historical reference Still valuable for: Sketching Taking measurements Other related activities Still used by some companies for certain applications

Automatic Pencils Common for manual drafting, sketching, and office use Do not require sharpening Available in several different lead sizes Combination of 0.5, 0.7, and 0.9 mm pencils and leads good for sketching and daily use

Lead Grades Different grades of hardness for specific techniques 2H and H good for typical daily office use 2H to F for thick lines 4H to H for thin lines 6H or 4H for construction lines and guidelines

Compasses Especially useful for large circles and arcs More time consuming than a template Bow compass (shown)

Dividers Bow Proportional

Parallel Bar Draw horizontal lines Use triangles to draw vertical lines and angles

Triangles Straightedge Draw angles Connect points 30°–60° triangle Angles of 30°–60°–90° 45° triangle Angles of 45°–45°–90°

Templates Circles Ellipses Letters Specific requirements and drafting disciplines Examples: Architectural symbols Electronic schematic symbols

Irregular Curves Have no constant radii French and flexible curves Radius curve

Drafting Machines Generally take the place of triangles and parallel bars Maintains a horizontal and vertical relationship between scales Scales serve as straightedges Protractor allows scales to be set quickly at any angle

Arm and Track Drafting Machines

Scale Measurement instrument Specific scales for mechanical, architectural, civil, and metric drawings Used by manual drafters to help create scaled drawings Still useful for sketching, taking measurements, and related tasks Four basic shapes

Scale Concept A universal and critical design and drafting concept

Drawing Scale Drawings are scaled so the objects represented can be illustrated clearly on standard sizes of paper Depends on: Actual size of the objects drawn Amount of detail to show Media size Amount of dimensioning and notes required

Inch Mechanical Drawing Scales Full scale = FULL or 1:1 Half scale = HALF or 1:2 Quarter scale = QUARTER or 1:4 Twice scale = DOUBLE or 2:1 Four times scale = 4:1 Ten times scale = 10:1

Drawing Scale

Metric Mechanical Drawing Scales Full scale = 1:1 Half scale = 1:2 One fifth scale = 1:5 One twenty-fifth scale = 1:25 One thirty-three and one-third scale = 1:33 1/3 One seventy-fifth scale = 1:75

U.S. Customary Architectural Drawing Scales 1/8" = 1'–0" 1/4" = 1'–0" 1/2" = 1'–0" 1" = 1'–0" 1 1/2" = 1'–0" 3" = 1'–0"

U.S. Customary Civil Drawing Scales 1" = 10' 1" = 20' 1" = 30' 1" = 50' 1" = 60' 1" = 100'

Metric Scale Any scale is a multiple of ten Any reductions or enlargements are easy to perform No mathematical calculations should be required

Civil Engineer’s Scale Divisions Ratio Scales Used with This Division 10 1:1 1" = 1" 1" = 1' 1" = 10' 1" = 100' 20 1:2 1" = 2" 1" = 2' 1" = 20' 1" = 200' 30 1:3 1" = 3" 1" = 3' 1" = 30' 1" = 300' 40 1:4 1" = 4" 1" = 4' 1" = 40' 1" = 400' 50 1:5 1" = 5" 1" = 5' 1" = 50' 1" = 500' 60 1:6 1" = 6" 1" = 6' 1" = 60' 1" = 600"

Civil Engineer’s Scale Any multiple of ten 10 scale often used for mechanical drawings at full, decimal-inch scale (1:1) 20 scale common for mechanical drawings at half scale (1:2) 20 scale used for scales of 1" = 2', 1" = 20', and 1" = 200' 50 scale popular in civil drafting

Architect’s Scale 11 different scales Ten of the scales Eleventh scale Inch represents a specific increment of feet Feet subdivided into multiples of 12 parts to represent inches and fractions of an inch Eleventh scale Full scale divided into 16 parts, each part equal to 1/16 of an inch

Mechanical Engineer’s Scale Common for mechanical drawings in fractional or decimal inches Full-scale divisions divided into 1/16, 10, and 50

Vellum Most common drafting media Inexpensive Good smoothness, erasability, and transparency Less durable and dimensionally stable Appropriate for regular graphite leads Well drawn graphite on vellum reproduces well

Polyester Film Mylar® Expensive Excellent durability, smoothness, erasability, dimensional stability, and transparency Best with ink or special polyester leads Well drawn ink on polyester film reproduces the best

Sheet Size and Format Standards for sheet size and format ASME Y14.1, Decimal Inch Drawing Sheet Size and Format ASME Y14.1M, Metric Drawing Sheet Size and Format Architectural, civil and structural drawings often use unique sheet format and may use unique sheet sizes

ASME Inch Sheet Size and Format [Insert Figure 2.31]

ASME Metric Sheet Size and Format

Selecting a Sheet Size Size of objects drawn Drawing scale Amount of additional content on the sheet Border Title block Drafting standards and company practice

G, H, J, and K apply to specific roll sizes ASME Inch Sheet Sizes Size Designation Size in Inches Vertical Horizontal A 8 1/2 11 (horizontal format) 11 8 1/2 (vertical format) B 17 C 22 D 34 E 44 F 28 40 G, H, J, and K apply to specific roll sizes

ASME Metric Sheet Sizes Size Designation Size in Millimeters Vertical Horizontal A0 841 1189 A1 594 A2 420 A3 297 A4 210 A1.0, A2.1, A2.0, A3.2, A3.1, and A3.0 apply to specific elongated sizes

Line Format Specified in ASME Y14.2M, Line Conventions and Lettering Thick lines of 0.6 mm (.02 in.) Borders Outline of principle blocks Main divisions of blocks Thin lines of 0.3 mm (.01 in.) Dividing parts lists and Revision History blocks Minor subdivisions of the title block and supplementary blocks

ASME Lettering Style Vertical uppercase Gothic Arial, Roman, or similar font when using CADD

ASME Letter Heights Sheet Elements Minimum Letter Heights INCH Drawing Sizes INCH Letter Heights METRIC (mm) Drawing Sizes METRIC Drawing title, sheet size, CAGE Code, drawing number, revision letter in the title block .24 D, E, F, H, J, K 6 A0, A1 .12 A, B, C, G 3 A2, A3, A4 Zone letters and numbers in borders All sizes Drawing block headings .10 2.5 All other characters

Border Format margin of a sheet Borderlines form a rectangle to establish the border ASME minimum distance from the edges of the sheet to borderlines: .5 in. for all inch drawing sheet sizes 20 mm for A0- and A1-size sheets 10 mm for A2-, A3-, and A4-size sheets

Zoning Allows the drawing to read like a road map Recommend by ASME standards for all sheets Optional for A, B, and A4 size sheets

Title Block Provides a variety of information about a drawing Size and location specified by ASME standards Other sheet blocks often group with the title block

ASME Title Block Revision of the part or drawing Principal drawing scale Actual or estimated weight Company or design activity Sheet relative to a group of sheets or set of sheets Title Approvals 1 Sheet size CAGE Code Approval 2 Drawing number Approval 3

Angle of Projection Block Third angle projection First angle projection

Dimensioning and Tolerancing Block

Revision History Block Zone Revision Description Date Approval

Revision Status of Sheets Block Not required on single-sheet drawings Horizontal or vertical Located by the title block or in the area of the Revision History block

Revision Status Notation ALL SHEETS ARE THE SAME REVISION STATUS Optional Next to the title block when the revision status of all sheets is the same

Additional Sheet Blocks and Symbols Margin drawing number block Application block Microfilm alignment arrows

Diazo Reproduction Ozalid dry prints or blue-line prints Not an actual blueprint Mostly replaced by photocopy reproduction and CADD prints

Photocopy Reproduction Photocopy printers or engineering copiers Photographically reproduces material, especially by xerography Advantages over diazo printing

Properly Folding Prints

Glossary Angle of projection block Application block Automatic pencil Specifies how to interpret a drawing according to the method of view projection. Application block Includes information such as next assembly and where used for drawings of a detail part or assembly of a component of a larger assembly. Automatic pencil A pencil with a lead chamber that advances the lead from the chamber to the writing tip by the push of a button or tab when a new piece of lead is needed.

Glossary CAGE Code Compass Dimensioning and tolerancing block A five number code assigned by the United States Defense Logistic Service Center (DLSC) to all Department of Defense contractors. CAGE stands for Commercial And Government Entity. Compass An instrument used to draw circles and arcs. Dimensioning and tolerancing block Specifies the general dimensioning and tolerancing specifications found on the drawing.

Glossary Dividers Drafting machine Ellipse Used to transfer dimensions or to divide a distance into a number of equal parts. Dividers are also used in navigation to measure distance in nautical miles. Drafting machine A machine that mounts to the table or board and has scales attached to an adjustable head that rotates for drawing angles. Ellipse A circle seen at an angle.

Glossary Manual drafting (hand drafting) Margin drawing number block Traditional drafting practice using pencil or ink on a medium such as paper or polyester film, with the support of drafting instruments and equipment. Margin drawing number block Identifies the drawing number and sheet number, and optional revision, when reading the margin information on the drawing. Media The material upon which you create drawings, such as paper or polyester film.

Glossary Microfilm Proportional dividers Revision History block A film on which drawings or other printed materials are photographed at greatly reduced size for ease of storage and sending from one place to another. When needed, equipment is available for enlargement of the microfilm to a printed copy. Proportional dividers Used to reduce or enlarge an object without the need of mathematical calculations or scale manipulations. Revision History block Also called the revision block, is used to record changes to the drawing.

Glossary Revision status of sheets block Scale Templates Appears on the first sheet of multiple sheet drawings and records the revision status of each drawing. Scale An instrument with a system of ordered marks at fixed intervals used as a reference standard in measurement. A scale establishes a proportion used in determining the dimensional relationship of an actual object to the representation of the same object on a drawing. Templates Plastic sheets with accurate shapes cut out and are used as a stencil for drawing the shapes.

Glossary Vellum Xerography Zoning Drafting paper with translucent properties that is specially designed to accept pencil or ink. Xerography A dry photographic or photocopying process in which a negative image formed by a resinous powder on an electrically charged plate is electrically transferred to and fixed as positive on a paper or other copying surface. Zoning A system of numbers along the top and bottom margins and letters along the left and right margins.