MMA0005 Reviewer M6-M7 PDF
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This document is a set of notes on technical drafting, covering topics such as alphabet lines, orthographic projection, auxiliary views, dimensioning, and various types of pictorial drawings. It includes explanations and examples.
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Module 6 **DRAFTING** It is the primary method of communication between; designers and client, architects and builders, engineers and production personnel, and between advertisers and customers **ALPHABET LINE** It is a set of line symbols used for interpretation of mechanical drawings The alph...
Module 6 **DRAFTING** It is the primary method of communication between; designers and client, architects and builders, engineers and production personnel, and between advertisers and customers **ALPHABET LINE** It is a set of line symbols used for interpretation of mechanical drawings The alphabet of lines consists of: - Border line - Visible line - Invisible line - Dimension line - Extension line - Leader line - Reference line - Center line - Long break line - Short break line **Border line** **Visible line** - A line used for showing the edges of an object that are seen **Invisible line** - Represents the part of the object that cannot be seen directly. It is a broken dashed line **Dimension line** - A line that represents the measurement of the object being drawn **Extension line** - A line used for showing the limits of the dimension **Leader line** - A fine broken line with an arrowhead at an end used for indicating the measurement and name of a part of the object being drawn **Reference line** - An irregular fine curved line with an arrowhead at one end used to label the parts of an object **CCenter line** - A line that represents the central point of circular object - A line that stand for the foreshortened of an object **Short break line** - A line that represents the foreshortened portions of an object just like the long break line. **ORTHOGRAPHIC DRAWING** - An orthographic drawing is a type of drawing which may not be pleasing to the eyes but it is easier to understand than other types of drawing - An orthographic drawing is a three view plan that consists of the three regular views - The term orthographic is derived from the Greek worth "orthos" and "graphos" - Orthos means write and graphos means to draw - It also means straight line drawing **SIX PRINCIPAL VIEWS** - TOP - LEFT SIDE - FRONT - RIGHT SIDE - BACK/REAR - BOTTOM TOP VIEW- the view directly at the top of an object FRONT VIEW- the view directly at the front of an object BOTTOM VIEW- the view directly at the bottom of an object RIGHT SIDE VIEW- the view directly at the right side of an object LEFT SIDE VIEW- the view is directly at the left side of an object BACK/REAR- the view directly at the back of an object **THREE REGULAR VIEWS** The top, front, and right side view are called the three regular views. This because they are the views that commonly used in orthographic drawing. **AUXILIARY VIEW** - The seventh view - The view directly to the inclined surface of an object - It represents the true shape and size of the inclined surface because it is foreshortened in the six principal views. **DIMENSIONING** - The process of placing measurements accurately both size and location dimension - Kinds of dimensions - Size dimension - Location dimension **KINDS OF DIMENSION** Location dimension - It is the measurement of the location of an object on the working paper Size dimensions - Give the detail and over-all sizes of the object. Overall dimensions - Are the total height, width, and depth of an object Details dimension - Are the length,width, and depth of the portion or parts of the same object **PRINCIPLES OF DIMENSION** **Width**- the measurement taken from the side to side of an object **Dept**h- the measurement taken from front to rear of an object **Height**- the measurement taken from top to bottom of an object ![](media/image2.jpg) **MODULE 7** **PICTORIAL DRAWINGS** - These drawings that show objects as they would appear in photograph - It is also a drawing that shows more than one side of the object - Examples of pictorial drawings are isometric, oblique, and perspective drawings **ISOMETRIC DRAWINGS** - The term isometric was derived from two words "iso" which means equal and "metric" which means measure - Isometric drawing is made possible by forming the three axes namely: Vertis axis, left 30-degree cross axis and 30 degrees right across axis **OBLIQUE DRAWING** - The word oblique means inclined - Characteristics of oblique drawings: The right side and top views are inclined 45 degrees to the horizon - The vertical lines should be done on 90-degree angle - Oblique drawing is always made to the exact measurements of the object **TYPE OF OBLIQUE DRAWING** - CAVALIER DRAWING : it is a cavalier drawing when the depth, and height of the drawing have true dimension. It means that the front, top and right-side views are drawn in true size - CABINET OBLIQUE DRAWING -- It is cabinet when the measurement of the depth axis is reduced to one-half. It means that the front view is drawn in the actual size but the depth of the top and right side views are drawn one-half of its actual size