Presentation on theme: "Drafting Equipment, Media, and Reproduction Methods"— Presentation transcript:
1 Drafting Equipment, Media, and Reproduction Methods CHAPTER 2Drafting Equipment, Media, and Reproduction Methods
2 Learning ObjectivesDescribe and demonstrate the use of manual drafting equipment and suppliesExplain the concept of drawing scale, and identify common inch and metric scalesRead metric, civil engineer, architect, and mechanical scales
3 Learning ObjectivesDescribe and use drafting media, sheet sizes, and sheet blocks and symbolsExplain common drawing reproduction methods
4 Manual Drafting (Hand Drafting) Mostly replaced by computer-aided design and drafting (CADD)Manual drafting and CADD require understanding the basics of draftingScaleSheet sizeSheet format
5 Manual Drafting Equipment and Supplies Historical referenceStill valuable for:SketchingTaking measurementsOther related activitiesStill used by some companies for certain applications
6 Automatic PencilsCommon for manual drafting, sketching, and office useDo not require sharpeningAvailable in several different lead sizesCombination of 0.5, 0.7, and 0.9 mm pencils and leads good for sketching and daily use
7 Lead Grades Different grades of hardness for specific techniques 2H and H good for typical daily office use2H to F for thick lines4H to H for thin lines6H or 4H for construction lines and guidelines
8 Compasses Especially useful for large circles and arcs More time consuming than a templateBow compass (shown)
10 Parallel Bar Draw horizontal lines Use triangles to draw vertical lines and angles
11 Triangles Straightedge Draw angles Connect points 30°–60° triangle Angles of 30°–60°–90°45° triangleAngles of 45°–45°–90°
12 Templates Circles Ellipses Letters Specific requirements and drafting disciplinesExamples:Architectural symbolsElectronic schematic symbols
13 Irregular Curves Have no constant radii French and flexible curves Radius curve
14 Drafting MachinesGenerally take the place of triangles and parallel barsMaintains a horizontal and vertical relationship between scalesScales serve as straightedgesProtractor allows scales to be set quickly at any angle
16 Scale Measurement instrument Specific scales for mechanical, architectural, civil, and metric drawingsUsed by manual drafters to help create scaled drawingsStill useful for sketching, taking measurements, and related tasksFour basic shapes
17 ScaleConceptA universal and critical design and drafting concept
18 Drawing ScaleDrawings are scaled so the objects represented can be illustrated clearly on standard sizes of paperDepends on:Actual size of the objects drawnAmount of detail to showMedia sizeAmount of dimensioning and notes required
19 Inch Mechanical Drawing Scales Full scale = FULL or 1:1Half scale = HALF or 1:2Quarter scale = QUARTER or 1:4Twice scale = DOUBLE or 2:1Four times scale = 4:1Ten times scale = 10:1
26 Civil Engineer’s Scale Any multiple of ten10 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
27 Architect’s Scale 11 different scales Ten of the scales Eleventh scale Inch represents a specific increment of feetFeet subdivided into multiples of 12 parts to represent inches and fractions of an inchEleventh scaleFull scale divided into 16 parts, each part equal to 1/16 of an inch
28 Mechanical Engineer’s Scale Common for mechanical drawings in fractional or decimal inchesFull-scale divisions divided into 1/16, 10, and 50
29 Vellum Most common drafting media Inexpensive Good smoothness, erasability, and transparencyLess durable and dimensionally stableAppropriate for regular graphite leadsWell drawn graphite on vellum reproduces well
30 Polyester Film Mylar® Expensive Excellent durability, smoothness, erasability, dimensional stability, and transparencyBest with ink or special polyester leadsWell drawn ink on polyester film reproduces the best
31 Sheet Size and Format Standards for sheet size and format ASME Y14.1, Decimal Inch Drawing Sheet Size and FormatASME Y14.1M, Metric Drawing Sheet Size and FormatArchitectural, civil and structural drawings often use unique sheet format and may use unique sheet sizes
32 ASME Inch Sheet Size and Format [Insert Figure 2.31]
34 Selecting a Sheet Size Size of objects drawn Drawing scale Amount of additional content on the sheetBorderTitle blockDrafting standards and company practice
35 G, H, J, and K apply to specific roll sizes ASME Inch Sheet SizesSize DesignationSize in InchesVerticalHorizontalA8 1/211 (horizontal format)118 1/2 (vertical format)B17C22D34E44F2840G, H, J, and K apply to specific roll sizes
36 ASME Metric Sheet Sizes Size DesignationSize in MillimetersVerticalHorizontalA08411189A1594A2420A3297A4210A1.0, A2.1, A2.0, A3.2, A3.1, and A3.0 apply to specific elongated sizes
37 Line Format Specified in ASME Y14.2M, Line Conventions and Lettering Thick lines of 0.6 mm (.02 in.)BordersOutline of principle blocksMain divisions of blocksThin lines of 0.3 mm (.01 in.)Dividing parts lists and Revision History blocksMinor subdivisions of the title block and supplementary blocks
38 ASME Lettering Style Vertical uppercase Gothic Arial, Roman, or similar font when using CADD
39 ASME Letter Heights Sheet Elements Minimum Letter Heights INCH Drawing Sizes INCHLetter Heights METRIC (mm)Drawing Sizes METRICDrawing title, sheet size, CAGE Code, drawing number, revision letter in the title block.24D, E, F, H, J, K6A0, A1.12A, B, C, G3A2, A3, A4Zone letters and numbers in bordersAll sizesDrawing block headings.102.5All other characters
40 Border Format margin of a sheet Borderlines form a rectangle to establish the borderASME minimum distance from the edges of the sheet to borderlines:.5 in. for all inch drawing sheet sizes20 mm for A0- and A1-size sheets10 mm for A2-, A3-, and A4-size sheets
41 Zoning Allows the drawing to read like a road map Recommend by ASME standards for all sheetsOptional for A, B, and A4 size sheets
42 Title Block Provides a variety of information about a drawing Size and location specified by ASME standardsOther sheet blocks often group with the title block
43 ASME Title Block Revision of the part or drawing Principal drawing scaleActual or estimated weightCompany or design activitySheet relative to a group of sheets or set of sheetsTitleApprovals 1Sheet sizeCAGE CodeApproval 2Drawing numberApproval 3
44 Angle of Projection Block Third angle projectionFirst angle projection
53 Glossary Angle of projection block Application block Automatic pencil Specifies how to interpret a drawing according to the method of view projection.Application blockIncludes information such as next assembly and where used for drawings of a detail part or assembly of a component of a larger assembly.Automatic pencilA 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.
54 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.CompassAn instrument used to draw circles and arcs.Dimensioning and tolerancing blockSpecifies the general dimensioning and tolerancing specifications found on the drawing.
55 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 machineA machine that mounts to the table or board and has scales attached to an adjustable head that rotates for drawing angles.EllipseA circle seen at an angle.
56 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 blockIdentifies the drawing number and sheet number, and optional revision, when reading the margin information on the drawing.MediaThe material upon which you create drawings, such as paper or polyester film.
57 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 dividersUsed to reduce or enlarge an object without the need of mathematical calculations or scale manipulations.Revision History blockAlso called the revision block, is used to record changes to the drawing.
58 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.ScaleAn 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.TemplatesPlastic sheets with accurate shapes cut out and are used as a stencil for drawing the shapes.
59 Glossary Vellum Xerography Zoning Drafting paper with translucent properties that is specially designed to accept pencil or ink.XerographyA 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.ZoningA system of numbers along the top and bottom margins and letters along the left and right margins.