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Basic Manual Drafting Equipment

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TheThe UseUse andand CareCare ofof DraftingDrafting EquipmentEquipment ChapterChapter 33 Sacramento City College EDT 300/ENGR 306 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment 1 ObjectivesObjectives Learn to properly and efficiently use basic drafting tools and equipment to produce technical drawings. 2 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment BasicBasic ManualManual DraftingDrafting EquipmentEquipment Vocabulary • India ink • Irregular curves Acute angle • Obtuse angle Alphabet of Lines • Opaque Angle • Protractor • Right Angle Circumference • Scales Compass • Symmetrical Drafting Film • T-Square Erasing Shields • Transparent Inclined • Vellum • Vertex 3 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment BasicBasic ManualManual DraftingDrafting EquipmentEquipment Drafting Board • Architect’s, engineer’s and T-Square or parallel-ruling straightmetric edgescale or drafting machine • Irregular curve Drawing sheets (paper, cloth, or film) • Drawing instrument set Drafting tape Drafting pencils • Brush Black drawing ink Pencil Sharpener Technical pens Erasing shield Triangle, 45o and 30o-60o 4 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment BasicBasic ManualManual DraftingDrafting EquipmentEquipment Drawing tables and desks Come in many different sizes and shapes Can be used standing or sitting Combination drafting table, desk and regular office chair is the most comfortable and efficient. See Figure 3-3. 5 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment DrawingDrawing BoardsBoards Drawing sheet is taped to the drawing board. Drawing boards usually measure: 9 x 12 16 x 21 18 x 24 Usually made of pine or basswood Made to stay flat and so the guiding edge will remain straight Hardwood or metal strips are used on some board edges to provide more durable edges. 6 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment TT--SquaresSquares A T-Square is an instrument that consists of a head that lines up with a true edge of the drafting board and a blade, or straightedge, that provides a true edge. Most have plastic-edged wood or clear plastic blades and heads of wood or plastic. If extreme accuracy is required, the T- square may be made of stainless steel. The blade must be very straight. The blade must be attached securely to the top surface of the T-head. See Figure 3-4. 7 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment CheckingChecking TT--SquareSquare AccuracyAccuracy To check the accuracy of a T-square On a clean sheet of paper, draw a sharp, thin line along the drawing edge of the T- square. Then, turn the drawing sheet around and line up the drawing edge of the T-square with the other side of the line. If the drawing edge and the pencil line do not match, the T-square is not accurate and should be replaced. See Figure 3-5. 8 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment DraftingDrafting MachinesMachines Two kinds are in use The arm or elbow type (Figure 3-6). The track type (Figure 3-9). The parallel bar type (Figure 3-9). 9 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment ArmArm oror ElbowElbow DraftingDrafting MachineMachine The anchor and two arms hold a movable protractor head with two scales. The scales are normally at right angles to each other. The arms allow the scales to be moved to any place on the drawing that is parallel to the starting position. Items are parallel when their edges are exactly the same distance apart at all points. 10 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment ArmArm oror ElbowElbow DraftingDrafting MachineMachine Most industrial drafting departments and many schools use drafting machines. Drafting machines combine the functions of the T-square, triangles, scales, and protractor. Allow you to draw more quickly and with less work. 11 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment TrackTrack--TypeType DraftingDrafting MachineMachine The track-type uses a horizontal guide rail at the top of the board and a moving arm rail at right angles to the top rail. An adjustable protractor head and two scales, usually at right angles, move up and down on the arm The scales may be moved to any place on the drawing that is parallel to the starting position. This type of drafting machine is easy to use on large boards or on boards placed vertically or at a steep angle. 12 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment OtherOther BasicBasic ToolsTools Triangles Drafters use two types of triangles in combination with the T-square to draw lines at various angles. Protractor A protractor is an instrument that is used to measure or lay out angles. Parallel-Ruling Straightedges Many drafters prefer this device to the drafting machine. 13 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment OtherOther BasicBasic ToolsTools Irregular Curves Also called French curves Used to draw noncircular curves They are made of sheet plastic Come in many different forms Sets are made for ellipses, parabolas, hyperbolas, and other special purposes. Flexible curves Curves which can be adjusted to complex curves that may be difficult to draw with other irregular curves. 14 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment DrawingDrawing MediaMedia Drawings are made on may different materials. 15 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment PaperPaper White, tinted, blue tint or pale green. White is used for drawings which will be photographed. Light colored papers reduce eyestrain and are less likely to soil. Opaque drawing papers are used for Permanent records Master drawings. Maps. Any drawing that will be photographed. 16 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment TracingTracing paperpaper Tracing paper Is translucent drawing paper Name was derived from the practice of first making a drawing in pencil on opaque paper, then “tracing” in ink on a sheet of translucent paper. Translucent papers allow “bluelines” or copies to be made. Natural papers made strong and durable are not very transparent. Papers with high transparency are only moderately durable. 17 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment VellumVellum Vellum Is tracing paper that has been treated to make it more transparent. Vellum provides strength, transparency, durability (handling and folding) and erasability without “ghosting”. 18 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment TracingTracing ClothCloth Tracing Cloth Is finely woven cotton fiber material cloth that has been sized with starch to provide a surface that takes pencil and ink. It comes in white for pencil tracings and blue for ink. 19 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment TracingTracing ClothCloth Tracing Cloth The working side is dull or frosted. You can erase without damaging the surface by using a soft rubber or vinyl eraser. Treated to provide a good working surface and good transparency. Is considerably more expensive than paper media. 20 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment TracingTracing ClothCloth Tracing Cloth Is subject to expansion and shrinkage. The drawing should be completed all at once. 21 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment MylarMylar (Plastic(Plastic Film)Film) Best qualifications for drawing media. Best for longevity, dimensional stability, great resistance to tearing, easy erasing with soft eraser and high transparency. Waterproof. Will not become brittle with age. Drawing surface is matte (dull and rough). Other side is very smooth, and will not accept graphite. 22 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment DrawingDrawing SheetSheet SizesSizes Drawing sheets follow standards set by American National Standards Institute (ANSI) OR International Standards Organization (ISO) 23 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment ANSIANSI SheetSheet SizesSizes American National Standards Institute (ANSI) provides two sets of standards which are commonly called the US Customary series. Both are developed upward in size from smallest to largest. 8.5 x 11 series OR 9 x 12 series 24 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment ANSIANSI SheetSheet SizesSizes Series based on 8.5” x 11” sheet. A - 8.5” x 11.0” B - 11” x 17” (keep the longest dimension (11); multiply the smallest dimension by 2; 2 x 8.5 = 17) C - 17” x 22” (keep the longest dimension (17); multiply the smallest dimension by 2; 2 x 11 = 22) D - 22” x 34” (keep the longest dimension (22); multiply the smallest dimension by 2; 2 x 17 = 34) E - 34” x 44” (keep the longest dimension (34); multiply the smallest dimension by 2; 2 x 22 = 44) 25 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment ANSIANSI SheetSheet SizesSizes Series based on 8.5” x 11” sheet. A - 8.5” x 11.0” B - 11” x 17” C - 17” x 22” D - 22” x 34” E - 34” x 44” 26 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment ANSIANSI SheetSheet SizesSizes Series based on 9” x 12” sheet. A - 9” x 12.0” B - 12” x 18” (keep the longest dimension (12); multiply the smallest dimension by 2; 2 x 9 = 18) C - 18” x 24” (keep the longest dimension (18); multiply the smallest dimension by 2; 2 x 12 = 24) D - 24” x 36” (keep the longest dimension (24); multiply the smallest dimension by 2; 2 x 18 = 36) E - 36” x 48” (keep the longest dimension (36); multiply the smallest dimension by 2; 2 x 24 = 48) 27 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment ANSIANSI SheetSheet SizesSizes Series based on 9” x 12” sheet. A - 9.0” x 12.0” sheet. B - 12” x 18” C - 18” x 24” D - 24” x 36” E - 36” x 48” 28 EDT 300/306 - Chapter 3 - Use/Care of Drafting Equipment ISOISO SheetSheet SizesSizes ISO Sheet sizes are developed downward in size from a base sheet with an area of about 1 square meter.
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