4.1 DESIGNING 71 Can you explain in your own words what to scale an object down means? Can you give an example? HVAC is an acronym that stands for Heating, Ventilation, and Air Conditioning. On wooden pencils, the H stands for hardness, the B stands for blackness. ONLINE RESOURCES The invention of the compass arrow: freccia dotted: tratteggiato drafting: disegno to ensure: assicurare to engrave: intagliare hand-sketched: disegnato a mano lead: punta (della matita) masking tape: nastro in carta per mascherature outline: contorno to size to scale: ridimensionare in scala steady: costante thickness: spessore width: larghezza 172 MeCHAniCs TECHNICAL LANGUAGE: DRAWING AND TOOLS Manual drafting or hand drafting is the practice of creating drawings by hand with pencil or ink on a media such as paper or polyester film using drafting instruments and equipment. Proper line width and darkness are necessary to produce a quality drawing; in addition, symbols and sizing to scale are used to convey placement of objects, surfaces, sizes, and other relevant information about the space being designed. Hand drafting was the preferred choice among professionals for a very long time, but the advent of more efficient and effective software technologies including computers and sophisticated software such as CAD have made design and drafting easier and less time consuming. Types of lines Thickness, width, and shape define the types of lines used to create a technical drawing. The most common are: section lines: thin, continuous lines used for section views, dimensions, and projections; thick lines: dense, continuous lines used for visible outlines; dashed lines: dotted lines to visualise hidden details; extension lines: thin lines that extend from the edge of the drawing and help identify the ends of a specific part; dimension lines: thin lines (between two extension lines) with an arrow on each end to indicate the dimension of a section. Moreover, different coloured lines represent a specific system, such as electrical, plumbing, HVAC , and structural. Equipment for manual drafting Usually, a technical drawing is handsketched before being reproduced by a computer-aided system. Some of the basic tools used by are: paper: it can have a specific format, texture, and thickness; technical pens: they have a thin metal tube that ensures the steady flow of the ink to the paper, resulting in a uniform line width; mechanical pencils: they have a graphite lead and can draw lines of constant width ; drafting table: it is a professional desk suitable for large sheets of paper; set-square: it is used to draw lines at a right angle (90°); T-square: it is used to draw horizontal lines on a drafting table; compass: it is used to inscribe arcs or circles; protractor: it measures angles; templates or stencils, allowing for the easy drawing of certain objects, symbols, common shapes, or text; stainless steel clips, to secure the corners of the sheet to the board; drafting paper, erasers, sharpeners, drafting and masking tape.