MEMB113 ENGINEERING GRAPHICS & CAE 02 Engineering Graphics & Sketching

Contents Overview Sketching Engineering graphics & manual drawing Drawing tools Drawing sheets and layout Lettering Lines Scale Abbreviations

Overview Engineering graphics communication involves the use of visual material to convey technical ideas and problem solutions. Engineering or technical drawing – one of the most widely used method. Definition of drawing: A graphic representation of an idea, concept or an entity which actually or potentially exists in life.

Overview Importance: A way of communication between engineers at all stages of the design & problem solving from initial ideas, design, analysis & manufacturing. For Visualisation, Communication and Documentation Visualisation The ability to mentally picture things that do not exist in front of the eyes. Communication The design solution should be communicated to others without ambiguity Documentation Permanent record of the solution for future reference.

Overview Types of drawing : artistic technical Illustrations rendering

Overview Examples of different drawing types 3-D computer model of the interior of an office building A dimensioned technical/mechanical drawing

Sketching

Sketching 3 methods of creating technical drawings Freehand, mechanical & digital Technical sketching is the process of producing a rough preliminary drawing representing the main features of a product or structure Normally done by freehand, generally less finished, less structured/ restricted, & take less time to produce

Sketching Technical sketches Used extensively in the first stage of design process to visualise or convey ideas An informal tool used by everyone involved in the design & manufacture of a product

Sketching Sketching tool Sketching technique e.g. Paper, pencils, eraser Sketching technique e.g. Straight line sketch Circle & arc Component (proportional sketch) Pictorial sketch In sketching, proportionality is important. Even though it is a freehand sketch, the lines should be relatively sharp and straight for a good quality sketch. Mechanical Sketched

Sketching Sketching straight line

Sketching component (proportional) Sketching circle Sketching component (proportional) Sketching circle

Sketching Multi-view and pictorial sketches

Engineering Graphics & Manual Drawing

Engineering graphics Drawings are widely used in engineering applications: manufacturing, design, structural, electrical, etc. Standards and conventions To ensure everybody using the same method Commonly used: ANSI, ASME, ISO, JIS, MS, DIN, BS What will you learn Producing engineering drawings Interpreting engineering drawings Graphics theory, visualisation, standards, conventions, applications,etc.

Engineering graphics E.g. Anatomy of a technical drawing MEMB113 | MANUAL DRAWING | CHAPTER 1 Engineering graphics E.g. Anatomy of a technical drawing

Drawing layout One of the important aspect in technical drawing is the layout What is drawing layout? Example of engineering drawing with layout Paper size ‘Components’ of a layout Title block Our layout

Drawing layout Drawing layout is the standard template and components of a drawing E.g.

Drawing layout Drawing sheets – paper sizes Usually based on 'A' series Drawing sheets material - paper, linen, plastic film Drawing sheet layout Sheet frames or border Usually 20mm for A0 & A1, 10mm for others Title block or title frame Represents general information source for a drawing Usually at bottom right-hand corner A0 : 1189x841 A1 : 841 x 594 A2 : 594 x 420 A3 : 420 X 297 A4 : 297 X 210 A5 : 210 X 148 A6 : 148 X 105 All in mm

Drawing layout - components Revision Table A revision table is normally located in the upper right of the drawing frame, or at the bottom on the left side of the title block. All modifications to the drawing should be documented here. Material or Parts List If the drawing contains a number of parts, or if it is an assembly drawing, a tabulated parts list is attached to the bottom right of the drawing frame, just above the title block. The parts list should give the following information: the part number the part name the quantity required material specifications the drawing number of each individual part other applicable information When the parts list is very large a separate drawing sheet may be used for the parts list alone. Zoning A drawing may be divided up into a grid using letters and numbers. When zoning is used it is located inside the drawing frame. Zoning allows easy references to various parts of the drawing by referencing a coordinate such as C7. Title Block The title block is normally placed in the bottom right of the drawing frame, and it should contain the following information: - the name of the company or organization - the title of the drawing - the drawing number, which is generally a unique filing identifier - the scale - the angle of projection used, either first or third, generally shown symbolically - the signature or initials of the draftsman, checker, approving officer, and issuing officer, with the respective dates -other information as required http://www.metrication.com/drafting/layout.htm

Drawing layout – title block A title block is the form on which the actual drawing is a section. The title block includes the border and the various sections for providing quality, administrative and technical information.   The importance of the title block cannot be minimised as it includes all the information which enables the drawing to be intepreted, identified and archived. E.g.

Drawing layout - title block A title block is the form on which the actual drawing is a section. The title block includes the border and the various sections for providing quality, administrative and technical information.   The importance of the title block cannot be minimised as it includes all the information which enables the drawing to be intepreted, identified and archived. The title should include sufficient information to identify the type of drawing e.g general arrangement, or detail. It should also clearly describe in a precise way what the drawing portrays The basic requirements for a title block located at the bottom right hand corner of a drawing are The registration or ID number The drawing title The Legal Owner of the Drawing These items should be written in a rectangle which is at the most 170mm wide. The tile block should also include boxes for the legal signatures of the originator and other persons involved production of the drawing to the required quality. The drawing should also include a symbol identifying the projection. The main scale and the linear dimension units if other than "mm". The drawing title block should indicate the date of the first revision.   In separate boxes to the title block the current revision with an outline description of the revision should be indicated.    On completion of each drawing revision an additional revision box should be completed thus provide a detailed history of the drawing. http://www.roymech.co.uk/Useful_Tables/Drawing/Title_blocks.html

UNIVERSITI TENAGA NASIONAL Our layout UNLESS STATED OTHERWISE ALL DIMENSIONS IN mm TOLERANCES LINEAR: ANGULAR FINISH AS MACHINE MATERIAL CAST STEEL DRAWN BY MY FULL NAME IS VERY LONG ME 000000 SEC 01A DATE: 04/07/2005 CHECKED BY UNIVERSITI TENAGA NASIONAL DRAWING TITLE SCALE 1:1 DWG NO. 001 SHEET 1 OF 1

Lettering Text is an important part of a technical drawing. Not all info required on technical dwg can be communicate graphically such as dimensions. One method of creating text is by freehand lettering. The standard style for freehand lettering is single-stroke Gothic lettering.

Lettering Characteristic of good lettering Should be neat, not sloppy MEMB113 | MANUAL DRAWING | CHAPTER 2 Lettering Characteristic of good lettering Should be neat, not sloppy Should be uniform and consistent i.e. same height, proportion & inclination – use guidelines Should have proper spacing of letters and words Should not contain unnecessary frills Should use capital letters except for standard abbreviation e.g. mm, kg Recommended minimum height 2.5mm Recommended height 5mm to 7mm Underlining of lettering should be avoided

Lines Pencil Description Example B/2B/0.5mm Continuous thick Different line types for different purposes - to ensure drawing to be read quickly & accurately Types of lines and thickness of line Commonly used line types & thickness: Pencil Description Usage Example B/2B/0.5mm Continuous thick Drawing outlines & visible edges   Continuous thin Hatching, dimension & projection lines Continuous wavy thick Limit of partial view Dashed thin Hidden detail Long & short dash thin Center lines 2H/H/ 0.3mm B/2B/ 0.5mm 2H/H/ 0.3mm 2H/H/ 0.3mm

Standard line types used in technical drawing Lines Standard line types used in technical drawing

Scale What does it mean? Scale indicates the relative size of the drawing object with the real object Scale used should always be stated on drawing – a very important info that is usually written in the title block. 'do not scale' / 'not to scale‘ / NTS – the drawing is not drawn to a certain scale Recommended scale 1:1 for full size for greater than full size 2:1 for twice full size 10:1 for ten times full size for reduced size 1:2 for half full size 1:10 for tenth full size other common scale 1:5, 1:20, 1:50, 1:100, 1:500 etc. Actual size 1:1 2:1 1:2

Abbreviations

End of chapter [02] References: Engineering Drawing, A.W. Boundy, McGraw-Hill, 2000 Fundamentals of Graphics Communication 3rd Edition, Gary Bertoline & Eric Weibe, McGraw-Hill