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Technology 3 Photocopy ___ Scale drawings 1.4 SCALE DRAWINGS A scale drawing is a drawing that represents a real object. The scale of the drawing is the ratio of the size of the drawing to the REAL size of the object. NUMERICAL GRAPHICAL NATURAL SCALE When the drawing of the object has the same dimensions as the real object. Its scale is 1:1 1.4.1 Reduction Scale: The object is proportionally reduced on the drawing Normalized scales 1:2 (or 1/2 ): Pronounced "One to Two". HALF SIZE : 1 millimeter on paper =2 millimeters on the artifact. The drawing is half the size of the artifact. 1:4 (or 1/4 ): Pronounced "One to Four" Other normalized scales: 1:5, 1:10, 1:20, 1:50, 1:100, 1:200, 1:500, 1:1000, 1:2000, 1:5000, 1:10000 Page 1 of 5. Scale drawings Technology 3 Photocopy ___ Scale drawings How to understand the measurements on a reduced scale drawing? 1.4.2 Enlargement scale Small objects (like chips, screws...) can be too small to be draw, so we use an enlargement scale so that the drawing is proportional to the object but bigger. Some of the most commons enlargement scales are: Page 2 of 5. Scale drawings Technology 3 Photocopy ___ Scale drawings EXERCISES 1. Think of how you can draw this objects on a piece of paper and complete the table below: THE SAME BIGGER SMALLER Your city map Your home plan A car A pair of scissors A pencil A pencil sharpener Machinery inside a watch A molecule 2. What are these scales enlargement, reduction or natural scales? Scale 1:2 5:1 1:10 20:1 10:1 Natural scale example Reduction scale example Enlargement scale example 3. Follow the examples and complete these scales tables values Scale Drawing Reality Scale Drawing 5:1 20 mm 100 mm 2:1 24mm 1:50 4 cm 200 cm 50:1 50cm 1: 10 10 cm 10:1 2,4cm 1:50 20 cm 10:1 1,5cm 1:1000 25 cm 50:1 0,7.m 1:5000 23 cm 1:1 1:2 12 mm 1:5 10 cm 12cm 2,6 cm 1000 m 100 m Reality 2:1 1,3 mm 16,7 cm 26 cm 13 mm 4. The length of the highway is 600 km. If 0.5 cm represents 50 km, what is the length of the highway on the map? Page 3 of 5. Scale drawings Technology 3 Photocopy ___ Scale drawings 5. The dimensions of a building are 250 m by 120 m. If 1 cm represents 20 m on a scale drawing, what are the dimensions of the building on the drawing? What is the scale? 9. Write the numbers on the dimension lines of this truck, which is drawn to a scale 1/50. 10. Write the value of the length indicated on the screw (drawn to a natural scale 1/1). 11. To what scale is this basket field drawn (it is dimensioned in m). Page 4 of 5. Scale drawings Technology 3 Photocopy ___ 12. Draw this piece to a scale 1/250. 13. Dimension this house to scale 1/100. 14. Dimension this room to scale 1/50. Page 5 of 5. Scale drawings Scale drawings Technology 3 Photocopy ___ Page 6 of 5. Scale drawings Scale drawings