Measuring Tools, Materials, and Equipment PDF
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Lanao del Norte National Comprehensive High School
Kristine M. Capao
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This information sheet provides an overview of measuring tools, materials, and equipment used in drafting, including T-squares, triangles, compasses, dividers, protractors, and scales. It details the different types of each tool and their uses in technical drawing.
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INFORMATION SHEET 1-1.3 Measuring Tools, Materials and Equipment Learning Objectives: After reading this INFORMATION SHEET, YOU MUST be able to: 1. Select and prepare drawing tools, materials equipment based on the job requirements. 2. Proper care,...
INFORMATION SHEET 1-1.3 Measuring Tools, Materials and Equipment Learning Objectives: After reading this INFORMATION SHEET, YOU MUST be able to: 1. Select and prepare drawing tools, materials equipment based on the job requirements. 2. Proper care, handling and maintain measuring tools. 3. Accurately read and interpret measurements. 4. Apply correct measuring techniques and formulas. 5. Identify and assess alternative tools for cost and quality. Measuring Tools, Materials, and Equipment Drawing Tools These refer to the sets of tools that are used in drafting works or activities that require mechanical presentation. Prior to the start of drafting activity, it is expected therefore that all drawing tools needed must be available in the workstation to ensure that the assigned task can be accomplished according to job specifications. The following are the common drafting tools: T-square It is a drawing instrument used when making horizontal lines. It is also used for guiding triangles when drawing vertical lines. It is recommended to use a 24-inch or 36-inch length T-square. There are three (3) types of T-squares, namely: 1. Fixed Head. The head is fastened to the blade. It is used for ordinary work. 2. Movable Head or Adjustable Head. It has one fixed and one adjustable head and used only for occasional drawing. Document No. Date complied: Issued by: June 2024 Page 38 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # 3. Detachable Head or Removable Head. It is designed for comfort when carrying the T-square. Triangles It is a three-sided ruler, which typically has two equal sides meeting at a 900 angle and to a third side at 450, 300, including 600 angles. It is usually made of plastic and comes in different sizes. If in use, the base of the triangle must rest on the blade of the T-square. Drawing a line always 45ᴼ x 45ᴼ starts from the point near the base going upward. Commonly used 45° triangle triangles are: a. 450 450 b. 300 600 30ᴼ x 60ᴼ 30°–60° triangle Angles that may be made with the 30°– 60° and 45° triangles Document No. Date complied: Issued by: June 2024 Page 39 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # Compass It is used when drawing arcs and circles. It is composed of one with the pen leg and the needle point leg being held together with a handle. This drawing instrument can be used for both penciling and inking. Divider This is used when transferring measurements, dividing lines and arcs into the desired number of equal parts. It can easily transfer accurate measurements by adjusting the divider points. Constant correct practice is necessary before doing an actual work for quick and easy control when use. Protractor It is a semi-circular instrument divided into 180 equal parts, each of which is called a degree. It is used to determine gradations of the degrees when measuring arcs, angles, and circles. High quality protractors are usually made of plastic. Scales (Drawing Scale) All instrument drawings are drawn accurately at one size, which may be a reduced or an enlarge size, so that all features of the part are in proportion. Such a drawing is said to be drawn “to scale”. Some drawings are drawn to a reduced size, and some are drawn to an enlarge size. Since construction projects – piping, structural, architectural, and civil – are large and the paper size is small, all these drawings are done at a reduced scale. The instrument used to measure and layout these drawings is called a scale (not a ruler – a ruler makes only full-size measurements). Scale is a tool generally used when reproducing a drawing in an enlarged or reduced form to some regular proportion. The five types of drawing scales are the metric scale, engineering scale, mechanical engineering scale, decimal scale, and architect’s scale. The most used triangular scale for general drawing is the architect’s scale. But to many, the metric scale is much easier to master and use. Its main function is to reproduce the measurements of an object in full size, reduced size, and enlarged size. Document No. Date complied: Issued by: June 2024 Page 40 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # Trianguler Metric Scale The full-size metric scale is divided into major units of centimeters and smaller units of millimeters. There are 10 millimeters in each centimeter. Metric units, in full size as well as in reductions and enlargements, are being used more and more in all forms of design work. The figure above shows a triangular metric scale with measurements. To set off 80mm full size (1:1) start at the zero end of the 1:1 scale and count to the right until you get the 8 (8 cm = 80 mm). On the 1:5 scale ratio, the 4.5 mark on the scale gives you 4500 mm (or 4.5 m). Ruler It is the most popular type of measuring tool. It is usually 12 inches in length. It is needed for measuring sizes and distances. Document No. Date complied: Issued by: June 2024 Page 41 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # Drawing Templates This enables you to create exact circles, squares, lines, arcs, and more without reaching for a compass, ruler, or protractor. It is a necessary tool for executing clean-lined blueprints, sketches that demand precision, or crisp compositions for bullet journals. Irregular Curve Irregular curves are plastic (or wooden) templates having an edge composed of several different curves. French curves are used in drafting (or were before computer-aided design) to draw smooth curves of almost any desired curvature in manual drawings. Duster/Brush A duster or brush is used for cleaning instruments. It is also used to sweep away the crumps or dust formed after the use of an eraser on the drawing sheet. Drawing/Drafting Materials These are sets of consumable items that are specifically used in drafting works or activities. The draftsman cannot perform his drafting task without these items. The following are the required materials needed in drafting works: Drawing Paper Various types of drawing papers are available for use, but hard and soft surface drawing papers are highly recommended to be the best. This type Document No. Date complied: Issued by: June 2024 Page 42 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # does not groove easily when pressure is applied to the pencil. Tracing paper and Oslo paper are commonly used but bond paper is also recommended. When selecting a sheet size, consider the size of objects drawn; the drawing scale; the amount of additional content on the sheet, such as a border, title block, and notes; and drafting standards. In general, choose a sheet size that is large enough to show all elements of the drawing using an appropriate scale and without crowding. For example, the dimensioned views of a machine part that occupies a total area of 15 in. × 6 in. (381 mm × 153 mm), can typically fit on a 17 in. × 11 in. (B size) or 420 mm × 297 mm (A3 size) sheet. A larger sheet will likely display too much blank area and is an unnecessary use of material. A smaller sheet will not support the dimensioned views and the remaining elements of the drawing, such as the title block. Metric Sheet Sizes Document No. Date complied: Issued by: June 2024 Page 43 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # Drawing Pencils and Leads The pencils are used for preparing the drawings on the drawing sheet. The accuracy and the appearance of the drawing depend upon the quality of pencil used. Different grades of pencils are available depending upon the hardness of the lid. Pencils of various grades can be easily recognized by the letters marked on the body of the pencil. The pencils are generally graded as H, F, B and HB. H represents hardness; F represents firm, B represents softness and HB represents intermediate between hard and soft. The general designation of a pencil is associated with alpha-numeric symbols such as 2H, 3H, HB, B, 2B, 3B, etc. Figure 1 shows various grades of pencils. Drawing pencils are graded as 7B, 6B,...... , HB, H, 2H,...... in the increasing order of their hardness and decreasing order of their blackness. Generally, drawings are made with 2H pencils and finished with H or HB pencils. This is one of the most important tools in drawing. It comes in various grades. The grade of pencil to be used depends on the quality of paper to be used. You must take into consideration also the type of line work required. a. Hard pencils – are used where extreme accuracy is required, especially working on graphs, diagrams, and charts. b. Medium pencils – are used for general purpose work in drawing. c. Soft pencils – are too soft to be used in mechanical drafting. They are very useful for artwork of various kinds. The Range of Lead Grades Document No. Date complied: Issued by: June 2024 Page 44 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # A Mechanical pencil (sometimes known as a clutch pencil or refillable pencil) areused in drawings such as orthogonal or isometric drawings as they provide a veryconstant line thickness. The pencils come in a number of line thicknesses with the morecommon being 0.35, 0.5, and 0.7. These pencils can be very expensive as are the refills. Inking Pens (Technical Pens) - Technical drawings created in pencil are usually over-traced with ink torender durable final drawings. Early inking pens consisted of a mechanical device withan adjustable nib. Modern disposable inking pens have built in ink reservoirs and areavailable in many point widths. Technical Pen Sizes Masking Tape This is used for fastening the drawing paper on the drawing table or drawing board because it does not damage the board and it will not damage the paper if it is removed by pulling it off. Pencil sharpener Pencils should be sharpened whenever they show a sign of dullness. Various types and designs are available in the store for use. Document No. Date complied: Issued by: June 2024 Page 45 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # Eraser This is used to clean the dirt off the drawing. A soft eraser is advantageous in removing smudges and pencil marks, whereas a harder eraser is useful for making changes and correcting errors in the drawing. Drawing/Drafting Equipment These items are also essential in producing quality drafting output especially if the assigned task requires mechanical manipulation. Although these items are so expensive, these are important in making the drawing output presentable and convincing to the clients. The following are some of the equipment needed in drafting task: Drafting or Drawing Table/Board A drafting table or a drawing table is a multi-purpose platform intended for architecture, engineering, creative drawing, drafting, and sketching. A drafting board or a drawing board is a smooth board on which paper is placed for making drawings. Drafting/Drawing Table Document No. Date complied: Issued by: June 2024 Page 46 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # Drafting/Drawing Boards Drafting or Drawing Stool Drafting stools are designed specifically for architects, engineers, laboratory workers, draftsmen, and others who need durable chairs, resistant to wear and staining. They are also designed to allow people to perch and lean forward by offering convenient foot support. Drafting Machine / Mini-Drafter A mini-drafter is an instrument which combines together all the features of a T-square, set squares, scales and protractor and hence is a unified instrument capable of performing the functions of all these Document No. Date complied: Issued by: June 2024 Page 47 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # instruments put together. One end of the mini-drafter is clamped by means of a screw, to the distant longer edge of the drawing board. At its other end, an adjustable head (H) having protractor markings is fitted. Two blades (B) of transparent celluloid accurately set at right angles to each other are attached to the head. The machine has a mechanism (M) which keeps the two blades always parallel to their original position, irrespective of their position on the board. The blades have scales marked on them and are used as straight edges. The blades may be set at any desired angle with the help of the protractor markings. Computer An electronic device that manipulates information, or data. It can store, retrieve, and process data. Personal/Desktop Computer Laptop Document No. Date complied: Issued by: June 2024 Page 48 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # Plotter and Printers Plotters are used in the engineering and architectural industries to create large-scale technical drawings and blueprints. Nowadays, multifunction printers are widely used in printing A4-A3 technical drawings. Document No. Date complied: Issued by: June 2024 Page 49 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # INFORMATION SHEET 1-1.4 Maintain Hand Tools, Drawing Instruments, and Equipment Learning Objectives: After reading this INFORMATION SHEET, YOU MUST be able to: 1. Demonstrate the correct use of various measuring instruments in technical drafting. 2. Conduct routine maintenance and calibration of measuring instruments to ensure accuracy. 3. Follow proper care and storage procedures to maintain the condition and longevity of measuring tools. 4. Recognize common issues and wear that can affect the accuracy of measuring instruments. 5. Identify and assess alternative tools for cost and quality. 6. Implement safety guidelines and practices when using and handling measuring tools. A good set of drafting instruments can be quite an investment. Therefore, these must be well taken care of. Keeping your drafting tools clean, well maintained, and properly stored will result in better performance and longer service life. The performance of simple cleaning, maintenance, and storage procedures helps a lot in keeping the efficiency of every drafting instrument. The early detection and reparation of any signs of deterioration will enable the drafter to save time and resources in the future. To maintain the quality of work produced by a drafter, the tools he/she uses must always be at their optimum condition. A good drafter knows how to extend the service life of his/her equipment. Proper care, maintenance and storage are the key elements in sustaining the efficiency and precision of these implements. The following are common good practices in handling and caring for your drafting tools and equipment. Working with Drafting Pencils and Pens Sharpening the Pencil To sharpen a wooden pencil, cut away the wood at a long slope, as shown in Figure 4-13A. Always sharpen the end opposite the grade mark, being careful not to cut the lead. Leave about half an inch (13 mm) exposed. Then shape the lead to a long, conical point. Do this by rubbing the lead back and forth on a sandpaper pad or on a long piece of paper while turning it slowly to form the point, as shown in Figure 4-13B and 4- Document No. Date complied: Issued by: June 2024 Page 50 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # 13C. Some drafters prefer the flat point, or chisel point, shown in Figure 4-13D. Keep the sandpaper pad or the piece of paper at hand, so that you can sharpen the point often, as shown in Figure 4-14. Figure 4-13A Figure 4-14 Rub the pencil on a sandpaper pad, turning it slowly, to achieve a conical point. Never sharpen a pencil over the drawing board. After you sharpen a pencil, wipe the lead with a cloth or a Styrofoam™-type “stab-it” to remove the dust. Being careful in these ways will help keep the drawing clean and bright. Techniques for Using a Drafting Pencil Pencil lines must be clean and sharp; not fuzzy. They must be dark enough for the views to be seen when standard line widths are used. If you use too much pressure, you will groove the drawing surface. You can avoid this by using the correct grade of lead. Rotate the pencil between your thumb and forefinger as you draw to help make the line uniform and keep the point from wearing down unevenly. Using Erasers Use soft erasers to clean soiled spots or light pencil marks from drawings. Do not apply too much pressure when rubbing. Erase (press lightly) lines along the direction of the work. Too much pressure damages the surface and makes it hard to revise the drawing. Always erase carefully to avoid damaging the finish on the drawing sheet. Use an erasing shield to protect nearby lines and areas that you do not want to erase. Document No. Date complied: Issued by: June 2024 Page 51 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # Alphabet of Lines The different lines or line symbols used on drawings form a kind of graphic alphabet commonly known as the alphabet of lines. The line symbols recommended by ASME are shown in Figure 4-18. Two-line widths–thick and thin—are used. Drawings are easier to read when there is good contrast among different line widths. All lines must be uniformly sharp and black. Techniques for Drawing Lines Horizontal Lines To draw a horizontal line, use the upper edge of the T-square blade as a guide. With your left hand, place the head of the T-square in contact with the left edge of the board. Keeping the head in contact, move the T- square to the place you want to draw the line. Slide your left hand along the blade to hold it firmly against the drawing sheet. Hold the pencil about 1" (25 mm) from its point. Slant it in the direction in which you are drawing the line. (This direction should be left to right for right-handers and right to left for left- handers.) While drawing the line, rotate the pencil slowly and slide your little finger along the blade of the T-square, as shown in Figure 4-19. This will give you more control over the pencil. On film, keep the pencil at the same angle (55° to 65°) all along the line. You must also use less pressure on film than on paper or other material. Always keep the point of the lead a little distance away from the corner between the guiding edge and the drawing surface, as shown in Figure 4-20. This will let you see where you are drawing the line. It will also help you avoid making a poor or smudged line. Be careful to keep the line parallel to the guiding edge. Figure 4-19 Drawing a horizontal line. Figure 4-20 Document No. Date complied: Issued by: June 2024 Page 52 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # Vertical Lines Use a triangle and a T-square to draw vertical lines, as shown in Figure 4-21. Place the head of the T-square in contact with the left edge of the board. Keeping the T- square in contact, move it to a position below the start of the vertical line. Place a triangle against the T-square blade. Move the triangle to where you want to begin the line. Keeping the vertical edge of the triangle toward the left, draw upward. Slant the pencil in the direction in which you are drawing the line. Figure 4-21 Drawing a vertical line Be sure to keep this angle the same when you are drawing on film. Keep the point of the lead far enough out from the guiding edge so you can see where you are drawing the line. Be careful to keep the line parallel to the guiding edge. Inclined Lines Inclined lines are lines drawn at an angle that is neither horizontal nor vertical. They are drawn using triangles, a protractor, or a drafting machine. 30°, 45°, and 60° Lines Angles are measured in degrees, minutes, and seconds. You can draw lines at 30°, 45°, or 60° angles from the horizontal or vertical by using the triangles. Lines inclined at 30° and 60° are drawn with the 30°- 60° triangle held against the T-square blade, as shown in Figure 4-22 or against a horizontal straightedge. The 30°-60° triangle can also be used to lay off equal angles, 6 at 60° or 12 at 30°, about a center point. To draw lines inclined at 45° from horizontal or vertical lines, hold the triangle against the T-square blade, as shown in Figure 4-23, or against a horizontal straightedge. The 45° triangle can also be used to lay off eight equal angles of 45° about a center point. Lines Inclined at 15° Increments The 45° and 30-60° triangles, alone or together and combined with a T-square, can be used to draw angles increasing by 15° from the horizontal or vertical line. Some ways of placing the triangles to draw angles of 15° and 75° are shown in Figure 4-24. Document No. Date complied: Issued by: June 2024 Page 53 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # Figure 4-22 The 30°-60° triangle has angles of 30°, 60°, and 90°. Figure 4-23 The 45° triangle has angles of 45° and 90°. Document No. Date complied: Issued by: June 2024 Page 54 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # Figure 4-24 Drawing lines at 15° and 75° using the two triangles Using the Compass The compass is used to draw regular curves, such as circles and circular arcs. Leave the legs of the compass straight for radii under 2” (50 mm). For larger radii, make the legs perpendicu- lar (at a 90° angle) to the paper, as shown in Figure 4-30. When you need a radius of more than 8" (200 mm), insert a lengthen ing bar as shown in Figure 4-31 to increase the length of the pencil leg, or use a beam compass. Document No. Date complied: Issued by: June 2024 Page 55 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # Figure 4-31 Figure 4-32 Use the lengthening bar in compasses Adjusting the point of the for circles and arcs of large radii. compass To get the compass ready for use, sharpen the lead, then adjust the shouldered end of the needle point until it extends slightly beyond the lead point, as shown in Figure 4-32. You cannot use as much pressure on the lead in the compass as you can on a pencil. Therefore, use lead one or two degrees softer in the compass to get the same line weight. Line weight refers to the thickness and darkness of a line. Figure 4-33 Technique for drawing circles and arcs Document No. Date complied: Issued by: June 2024 Page 56 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # Storing Tools, Materials and Drawings When a session of drawing is finished, it is important that the tools, materials, and equipment, which has been in use, is stored neatly in clean and dry conditions. Dirty and damaged tools, materials and equipment does not help in the production of good, neat, and clean drawings. Drawing boards can be either placed in purpose-made racks or stacked one on top of the other. T-squares should be placed in properly made racks, which make sure that the drawing edges are not damaged and that their two parts do not become separate. Set squares must be kept in a clean condition. They may pick up dust and erasing particles and if they are stored in such a condition other tools/materials/equipment becomes dirty. Pencils can be placed in racks made from blocks of wood with appropriately sized holes. Compasses are easily damaged if not stored properly. The best method of storing drawings is to have a folder in which the drawings can be placed without being folded. Other drawings, such as those used to demonstrate the principles of working should be stored flat in drawers large enough to take them unfolded. Take care when placing drawings in folders or drawers. Careless handling can easily cause them to become damaged, even to be torn. Drawings must be kept clean if they are to be read easily. Document No. Date complied: Issued by: June 2024 Page 57 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision # References: Technical Drafting Training Regulation Technical Drafting Curriculum Based Curriculum K-12 Mechanical Drafting (Exploratory) Learning Module CBLM 3rd Year Drafting Technology - Draft Architectural Layout and Details, DepEd-Public Technical-Vocational High Schools, June 2009 https://www.splashlearn.com Manaois, German (2004) Drafting Volume 2. Quezon City, Phoenix Publishing House, Inc., pp 1-22. Document No. Date complied: Issued by: June 2024 Page 58 of Perform mensuration and calculations 62 Complied by: Kristine M. Capao Revision #