CONTENTS. 0. Foreword. Notes on the Use of the Document Section 11 General Principles of Dimensioning on Technical Drawings. Section 12 Indication of. Manual of British Standards in Engineering Drawing and Design. a few ideas in the designers head, through to rough sketches and notes, calculations. LECTURE NOTES. BASIC ENGINEERING DRAWING AND COMMUNICATION. Inquiries, Suggestions, Opinions etc should be forwarded to: Dr. Ballegu W R W.
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Engineering. Drawing The language is known as “drawing” or “drafting”. Both drawing types are used in technical drawing for communication. NOTES. LECTURE NOTES. For Environmental Health Science Students. Engineering Drawing. Wuttet Taffesse,. Laikemariam Kassa. Haramaya University. Here you can download engineering drawing book by n.d bhatt in pdf format. we' ve also provided Engineering Drawing Text Book and Notes of.
Figure shows an electrical layout superimposed on an outline taken from an architectural floor plan. The service line feeds power by way of a service switch to a lighting panel, from which three branch circuits run to the lighting fixtures and convenience outlets in the rooms. The symbols for these fixtures and outlets and the service switch are shown at the bottom of figure Elevations An elevation is a drawing that represents a view of the finished structure as you would see it from the front, back, left, or right.
There are interior elevations, such as a view of a fireplace, as well as exterior elevations, as shown in the elevations of a small building shown in figure Doors, windows, shapes of roof, chimneys, and exterior materials are shown. These views provide the viewer with a finished appearance. Few dimensions are given on elevations.
Only those vertical dimensions that cannot be shown on the plan are generally included on an elevation view. A Construction Electrician can quickly see from any one of the elevations in figure 2- 12 that there is an attic where easy access would be provided to electrical wiring.
This is important where there is a requirement for junction boxes that must be accessible. The electrician can also see a foundation wall where, if a service lateral is required, a conduit or sleeve must be placed for a later run of conduit. This knowledge will allow the electrician to plan ahead to work with the Builders when they build the forms.
The conduit will be placed in or through the form before the concrete is poured. It may also include other drawings that are necessary to present the system properly in relation to the other portions of the project.
Shop Drawings - Shop drawings are drawings and related data used to show some portion of the work prepared by the construction contractor, manufacturer, distributor, or supplier. Product data, such as brochures, illustrations, standard schedules, performance charts, and other information, are furnished by the contractor or the manufacturer to show a material, product, or system for some portion of the work. Engineering Aids are sometimes required to draft shop drawings for minor shop and field projects.
These drawings may include shop items, such as doors, cabinets, and small portable buildings prefabricated berthing quarters and modifications of existing structures , or they may come from portions of design drawings, specifications, or freehand sketches given by the design engineer. Working from a shop drawing is much like working from other working drawings. You convert the ideas you get from your interpretation of the lines and symbols into the product represented by the drawing.
These drawings show the arrangement and relationship of parts. Electrical diagrams are usually used to show how the parts of one or more pieces of equipment are wired together. There are several types of these diagrams. They are similar, yet different in some way. The short description of each that follows should enable you to recognize their differences. Isometric Diagram The isometric diagram is not often seen in electrical work.
It may be used to show the electrical wiring system in multilevel buildings. Appliances sometimes have an isometric diagram glued to an access panel so that it may be referred to for a quick look at an entire wiring system.
See fig. Figure shows a block diagram of a motor control system You can easily see how it gets its name. Sometimes the blocks are connected with only one line that may represent one or more conductors or cables.
Either major or minor components or parts may be represented by blocks. This type of diagram is often used to show something of the relationship of components in a power distribution system. The block diagram provides little help in troubleshooting.
Axonometric Projection For objects which are fairly small in size and reasonably close to the observer we often use a form of drawing known as axonometric projection. The word axonometric means 'measured axes'.
Axonometric drawings often appear distorted because they ignore the foreshortening effects of perspective foreshortening means the way things appear to get smaller in both height and depth as they recede into the distance. All axonometric drawings use vertical lines for those lines representing height and sloping parallel edges for all other sides.
There are a number of axonometric drawings. The smaller these angles are the less we see of the top surface. This ensures compatibility throughout the design process, from conception, through design, testing and manufacturing.
CAD organization and applications AutoCAD Mechanical is a purpose built 2D mechanical design solution providing an ideal platform for production drawing and detailing. Additional useful add-on programs are available for analysis and manufacturing solutions from MSC and Pathtrace, as well as document management solutions from Cyco.
Autodesk Inventor Series. For integrated 2D design and detailing, 3D assembly, parametric design and the capability to produce complex 3D surface models, Inventor Series 5 gives you the following compatible programs.
The series includes Autodesk Inventor 5. You get all of these technologies in one easy-to-use package giving you flexibility to use what you want when you want. No need to choose between 2D and 3D. A flexible display system used to manage and create plans, elevations, sections and 3D views.
Designed with an automatic scheduling feature and links to VIZ4. Building design information can be shared with the rest of the project team. Designs in 3D assist in coordination and approval with clients.
Autodesk VIZ 4 is a software program for design conceptualization and visualization, which combines modelling, texturing, and rendering features to create stunning visual presentations and walkthroughs.
The program quickly and simply generates 3D models and has a comprehensive library of materials and textures. Piranesi is a three dimensional paint program, which enables architects, artists and designers to produce high quality stylized artwork from 3D models. Unlike conventional 2D paint programs, Piranesi paint tools enable you to use colours, tints and textures a brick pattern say straight onto selected parts of an image, without overpainting other objects. It can be used by itself to produce artwork from AutoCAD models directly, but it really comes into its own when used as a post-processor for VIZ.
NavisWorks is a software program which can navigate and view models of extreme size and allow all design data to be brought together into one.
This facility enables faults to be detected early during project development 15 rather than on site after construction begins. The program automatically locates and highlights areas of the model where parts interfere or clash with each other.
Faults are easily communicated to others in the design team. A wide range of companies, contractors and designers can work on a single project without having to get together in the same place at the same time. This obviously reduces hidden project costs.
Autodesk Raster Design 3. Scanned paper drawings, aerial photos, satellite imagery and maps can be integrated into the computer system and edited raster data converted to vector. Vectorization Tools with Smart Correct technology create lines, polylines, circles, arcs, text and rectangles. Intersecting raster geometry can be preserved when raster entities are moved or erased. The program can read and write georeferenced images to and from the Web.
Raster design can help you gain more value from existing archive drawings and possibly avoid time-consuming redrafts. For many CAD users AutoCAD is too comprehensive, advanced and expensive for their needs and in cases where the draughtsman is mainly responsible for layout work and design work, which does not involve sophisticated modelling and rendering, then this program is well worth considering.
The ability to draw and to use the drawing, or part of the drawing, in a word processor document will be much appreciated. The software has a familiar feel as it uses the Windows interface, so if you have used pull-down menus, dialogue boxes and the drag and drop simplicity of Windows; you will soon master the basics since the Help feature provides an on-line guided learning assistance tour.
The toolbox and toolbar can easily be customized and arranged to suit your own preferences and style of working. The system will also accommodate a selection of symbol files. It is a low cost package, ideal for anyone who wants to use a computer to sketch or draw without investing in a full-scale system. Drawings, patterns and fonts are represented by simple symbols, or icons.
You can draw on multiple layers and look at them in any combination. Repetitive drawing is eliminated: you can use previously created drawings to build libraries of frequently used symbols, saving time. Having drawn an object you can move, copy, rotate, mirror, stretch and erase it until it matches your needs. You can group components together and treat them as one, and break them apart for editing.
Expanded memory support allows you to work with large drawings. Part clipping allows you to select items from existing drawing files and use them in others. Text and notes can easily be added or edited on the drawing using a variety of fonts.
The drawing features include line options, arcs, ellipses, circles, points, pattern fill areas, spline curves and polylines with variable line width. Automatic fillets and chamfers are possible, and the program also offers zoom and pan facilities. The program allows you to export drawings directly into AutoCAD, and a wide selection of desktop publishing packages.
Computer and software download It is strongly recommended that before any downloads are made, the client seeks advice from a recognized and authorized dealer, as they would be able to check that the equipment can perform the tasks you expect in your style of working. Practical demonstrations are very necessary before issuing orders. CAD equipment is a tool and there are possibly many ways of doing the same job. In this computer age it may well be that an experienced dealer can indicate a better and more productive way.
Your supplier would also give you a written specification for computers and software indicating any other relevant equipment required for protection and safe operation. Project development The reader will appreciate that the design of, for example, a large construction project from its conception, will involve technical input from architects and engineering designers in a wide variety of associated disciplines.
It is vital that all contributors to the overall scheme talk the same language and that only compatible computer software packages are in use for the separate areas of work. In addition, the management contractor must have access to the designs as work is in progress. Before the age of CAD it was the practice to have countless meetings in order to co-ordinate progress. Design obviously continues in steps and in planning and construction work problems arise, and designers need to be in a position to make modifications to overcome them, before progressing to the next phase.
The building services engineer must ensure that the environment to keep both controllers and equipment comfortable is maintained 24 hours a day, seven days a week. Due to the extensive use of computers at the centre, a huge amount of electrical, heating, ventilating and air conditioning plant needed to be installed.
Different specialist contractors were responsible for these services under the stewardship of the management contractor. At this development, it was accepted by contractors that for some drawings it was practical to work in three dimensions to make it easier, for example, to ensure clearances between piping and ductwork in the more cramped areas.
Layout drawings in 3D permitted engineers to demonstrate clearly to other parties where, for example, electrical cables and conduits were likely to plough straight through heating and ventilation ducts. Thus today it is often the case that the information travels from the mind of the designer into the manufactured component without having ever been codified by an engineering drawing.
In MBD, the dataset , not a drawing, is the legal instrument. The term "technical data package" TDP is now used to refer to the complete package of information in one medium or another that communicates information from design to production such as 3D-model datasets, engineering drawings, engineering change orders ECOs , spec revisions and addenda, and so on.
However, even in the MBD era, where theoretically production could happen without any drawings or humans at all, it is still the case that drawings and humans are involved. These workers often use drawings in the course of their work that have been produced by rendering and plotting printing from the MBD dataset.
In these cases, the drawing is still a useful document, although legally it is classified as "for reference only", meaning that if any controversies or discrepancies arise, it is the MBD dataset, not the drawing, that governs.
Systems of dimensioning and tolerancing[ edit ] Almost all engineering drawings except perhaps reference-only views or initial sketches communicate not only geometry shape and location but also dimensions and tolerances for those characteristics. Several systems of dimensioning and tolerancing have evolved. The simplest dimensioning system just specifies distances between points such as an object's length or width, or hole center locations.
Since the advent of well-developed interchangeable manufacture , these distances have been accompanied by tolerances of the plus-or-minus or min-and-max-limit types. Coordinate dimensioning involves defining all points, lines, planes, and profiles in terms of Cartesian coordinates, with a common origin. Common features[ edit ] Drawings convey the following critical information: Geometry — the shape of the object; represented as views; how the object will look when it is viewed from various angles, such as front, top, side, etc.
Dimensions — the size of the object is captured in accepted units. Tolerances — the allowable variations for each dimension.
Material — represents what the item is made of. Finish — specifies the surface quality of the item, functional or cosmetic.
For example, a mass-marketed product usually requires a much higher surface quality than, say, a component that goes inside industrial machinery.
Line styles and types[ edit ] Standard engineering drawing line types A variety of line styles graphically represent physical objects. Types of lines include the following: visible — are continuous lines used to depict edges directly visible from a particular angle. Section lines are commonly referred to as "cross-hatching". Lines can also be classified by a letter classification in which each line is given a letter.
Type A lines show the outline of the feature of an object. They are the thickest lines on a drawing and done with a pencil softer than HB. Type B lines are dimension lines and are used for dimensioning, projecting, extending, or leaders. A harder pencil should be used, such as a 2H pencil.
Type C lines are used for breaks when the whole object is not shown. These are freehand drawn and only for short breaks. These are dotted lines.