COMPUTER INTEGRATED DESIGN AND MANUFACTURING

INTRODUCTION TO AUTOCAD AND CONCEPT OF CAD AS DRAFTING AND DESIGNING FACILITY

Anurag Tewari

M.TECH (I & PE)

OVERVIEW

• AutoCAD is software for drafting and design, formally known as CAD software.

• Autodesk introduced and developed AutoCAD in December, 1982.

• AutoCAD has been very widely adopted throughout the world for its highlydeveloped two dimensional drafting capabilities. It also has three dimensionalgraphics and modelling capabilities.

• AutoCAD is a principal component of Mechanical Desktop (solid modellingsoftware) and works with 3D Studio (rendering and animation software), both ofwhich are produced by Autodesk.

• AutoCAD drawing files can be easily imported into many other software packages.

• AutoCAD is a software application used in architecture, construction andmanufacturing to assist in the preparation of blueprints and other engineering plans.

ABOUT AUTOCAD

• The first release of the software used only primitive entities such as polygons, circles,lines, arcs and text to construct complex objects.

• DWG (drawing) is the native file format .

• AutoCAD screen contains two parts: graphical screen and textual command.

• It can import and export different formats (DXF, IGES) and export different formats(DXF, IGES)

• There are two main domains within an Autocad, MODEL space and PAPER space.

• MODEL space contains all drawing or 'modelling' is done in here and it is the main‘modelling’ area in Autocad.

• PAPER space is an area used to print the drawing created in the model space. It isactually a blank sheet in which a real object drawn in can be represented as a printabledrawing in a proper scale.

GRAPHIC WINDOW

The five primary areas of the AutoCAD graphics window are as follows:

1. MenuBar -- AutoCAD's pull-down menus are accessed through the menu bar.

2. StatusBar -- The status bar provides status information including color, layer, coordinate display, and so on.

3. Drawing Area -- The center area, called the drawing area, is the area in which you draw.

4. Screen Menu -- The screen menu was AutoCAD's original menu interface, but is now primarily used for option selection.

5. Command Line -- The command line is the area where you enter commands and options from the keyboard. The command line prompts you for input and provides status on the results of AutoCAD commands.

DISTINCT FEATURES OF AUTOCAD

• Smart Dimensioning

• 3D free-form design tools

• Text Frame

• Status bar enhancement

• Resizable dialogue boxes

• Dynamic blocks

• Enhanced PDFs

FEATURES OF AUTOCAD 2017

• Autodesk desktop app

• Import PDF file

• Sharing drawings

• Making centreline and centre marks seamlessly

• Making 3d print ready file

• Migrate custom settings

• Enhanced graphics

USES

• As an architectural planning tool

• As an Engineering Drafting Tool

• As a Graphic Design Tool

• As an Industrial Design Tool

• In 3D Printing

• In the Fashion Industry

• Ship Design

• Civil 3D for environmental engineering

• Wiring diagrams, P&IDs, piping diagrams, store planning layouts etc.

DRAFTING

• Drafting is essentially drawing a picture, whether in 2D or 3D, and providing dimensions andnotes.

• It is used to create and edit 2D technical drawings and the draftsman convert the 2D drawings tomake sense "technically".

• Multiple angles and views to depict the association of components and systems.

• Drafting is done to prepare a visual depiction of a product to be constructed and uses CADimages to create plans to build and manufacture everything from buildings to toys to spacecraft.

• It should be able to visually communicate concepts and be very detailed in the drawings andsketches

• Drafters use CAD software to produce detailed drawings that include building dimensions,required materials and construction procedures.

• Drafters often consult with co-workers on design and layouts.

• In some cases, drafters coordinate with builders to establish requirements and understand designconcepts. When deficiencies occur, drafters revise designs to eliminate problems.

DRAFTER

• Professionals who use AutoCAD are often referred to as drafters.

• Drafters work in a number of specialties and the five most common specialization areasare as follows: mechanical, architectural, civil, electrical, and electronics.

• Mechanical drafters prepare plans for machinery and mechanical devices.

• Architectural drafters draw up plans for residential and commercial buildings.

• Civil drafters draw up plans for use in the design and building of roadways, bridges,sewer systems, and other major projects.

• Electrical drafters work with electricians to prepare diagrams of wiring electrical systemlayouts.

• Electronics drafters also prepare wiring diagrams for use in the making, installing, andrepairing of electronic gadgets

BENEFITS OF DRAFTING

• Increase productivity and accelerate the mechanics of drafting a design.

• Eliminating the need for stencils and technical drawing instruments.

• Develop site plans, refine concepts, sketch technical drawings and shareyour ideas.

• Customize templates and drawings more precisely.

• Collaborate with colleagues and clients using other compatible Autodesksoftware products.

• Create, send, and receive compatible data files when using genuine DWGfile formats to collaborate with clients and associates.

• All AutoCAD products support the DWG file format, so we can easilyreview 2D drawings in 3D programs.

BASIC AUTOCAD DRAFTING FUNCTIONS

• Lines, circles, arcs, polylines, rectangles, polygons, splines, points, texts, and areahatching.

• Moving, rotating, copying, mirroring, and erasing.

• Viewing ,Zooming and panning, multiple viewport generation, user coordinate system.

• Linear dimensions, angular dimensions, radius dimensions, diameter dimensions, baselinedimensions, continuous dimensions, leaders, and size and geometric tolerances.

• Wireframe images, hidden line images, shading images, and rendering mages.

• Layers, colors, linetypes, groups, blocks, attributes, and references.

• Plotting.

• Generation of PostScript files.

DRAWING AND DRAFTING TOOLS

• Object snap tracking

• Polar tracking

• Multifunctional grip

• Array enhancement

• Qselect

• Layer and object properties

• Hide and isolate

• Object selection cycling

DESIGNING

• Design is the next step to drafting.

• Designing is sketch and it is an analysis to justify the selection ofcomponent sizes based on stress, deflection, fatigue, etc.

• It determines the system dynamic response and assures that criteria aremet.

• A designer conceives an idea and follows through with the actual designkeeping in mind form and function. The designer imparts knowledge andunderstanding to the process.

• Design involves conception and 3D modelling

• Using Computer Aided Design, a designer comes up with ideas and brings them to reality.

DESIRABLE FEATURES OF AUTOCAD AND SETTING

PARAMETERS

General features

• AutoCAD enable its users to draw anything that they could imagine.

• It presents numerous ways in which users can do the similar tasks.

• Users of AutoCAD can do anything from modifying the program’s menusto creating custom applications using AutoCAD programming language.

• It offers high level of speed, accuracy and ease of use. With this accuracyone can create a computer model of earth and include the details down tosub micron level.

• If you want to include a photograph in your drawing then youjust have to copy the image and paste it into the AutoCAD.

• With windows, you have a freedom to arrange AutoCAD’sscreen by clicking and dragging its components.

• It also makes use of World Wide Web (www). You can open,save drawings across the internet, collaborate with others andpublish electronic print of your drawing.

• It also provide customization option through VBA.

Desirable features

CAD features for design and documentation

The new version of AutoCAD is the 2017 version which hasbeen updated by the Autodesk with six new features and theyare keep on adding new features to the AutoCAD everyday.

1. PDF to DWG

• This is probably the most awaited feature in AutoCAD, startingwith AutoCAD 2017 you can import drawings from PDFformat to AutoCAD as geometry and text objects.

• So far there were many third party tools which in my opinionwere very buggy and inefficient in doing the so called task ofconverting PDF to DWG drawings hence addition of thisfeature is a great enhancement to AutoCAD features.

• To use this feature type PDFIMPORT on command line andpress enter then select file from command line and locate PDFfile from your computer and click on open. Now an Import PDFwindow will open select all required options from this windowand click on OK.

2. Sharing drawings

• You can now directly share files with users who don’t even haveAutoCAD using A360 cloud account and all they need is a webbrowser for accessing shared drawing.

• To share a drawing make sure you are logged into your Autodesk 360cloud account and your drawing is saved.

• Click on application button on top left of AutoCAD windowselect publish then design views from options. Select one of the twooptions from next notification window and wait for the drawing toupload and process for viewing.

• Once your drawing is ready for viewing you will get a bubblenotification in your AutoCAD window click on it to open the drawingin web browser. Click on get link icon on top right corner of A360viewer and copy the link. You can now share this link with users andend user will not even require AutoCAD software or A360 accountfor viewing this drawing.

3. Centre lines and centre marks

• With new AutoCAD 2017 you can easily add centre lines and centremarks to the geometry. Simply type the command CENTREMARKand click on circular object to create the centre mark, you can use thiscommand to make a centre mark on circle, arc and fillet.

• In order to create a centre line between objects such as two parallel orintersecting lines type command CENTRELINE press enter andselect both parallel or intersecting lines. A centre line will be createdin between both the lines.

• These centre lines and centre mark will remain associated with theobjects with reference to which they are created and when youchange position of those original objects then these centre line andcentre mark will change itself to reflect new updated position.

4. Making 3D print ready file

• With new Autodesk print studio you can make a 3D print ready fileand directly print it in almost all types of 3D printers. This 3Dprinting tool is provided by spark technologies and it is available for64 bit machines only.

• To use this tool go to AutoCAD 3D modelling workspace and selectprint studio tool from 3D print panel of output tab. If you are usingthis tool for the first time then a prompt will appear from where youcan download this tool.

• Once downloaded and installed click on print studio tool again andclick on watertight or closed mesh object from your drawing whichyou want to use for 3D printing.

• This model will open in new Print studio window where you canprepare this model for 3D printing. If you are not yet ready to printthis drawing then you can export it as STL file which can be usedlater.

5. Migrate custom settings

• The new custom settings migration setting window is more visuallyappealing and has easy to understand interface.

6. Graphics

• In the previous releases of AutoCAD, the preview of objects as they arebeing created, moved or copied could appear jagged.

• In AutoCAD 2017, line smoothing is supported during the preview, soobjects appear just as they will appear after the operation is completed.

Setting parameters

• With the use of numerical parameters, you can change your drawing byadjusting values instead of working directly with linework. This is wherethe idea of parameter driven programs such as Revit comes from.

• Point-Defines a point (XY coordinate) on the geometry. Move or stretchfrom that point.

• Linear-Defines a linear distance. Specify a start point and an endpoint.Move, scale, stretch, or array along the line between the two points.

• Polar-Defines a linear distance and displays an angle. Specify a start pointand an endpoint. Move, scale, stretch, polar stretch (stretch at an angle), orarray along the line between two points and at a specified angle.

• XY-Defines X and Y distances. Specify a start point and an endpoint at anangle, and the parameter separately labels the X and Y distances. Move,scale, stretch, or array at specified X and Y distance.

• Rotation-Defines a base point, radius, and default rotation angle . Rotatearound the base point.

• Flip-Defines a reflection line. Specify the base point and endpoint of theline. Flipping is like mirroring.

• Visibility-Controls the visibility of components in the block. No action isrequired, but you need to define the visibility states and which componentsare visible or invisible in each state.

• Lookup-Defines preset values that you specify. You then create labels foreach value. When you edit the block in a drawing, choose one of the labelsfrom the list to modify the block according to the values.

• Base point-Defines a base point for the Dynamic Block. Use this parameterwhen you want a base point to maintain its relationship to the block asother parts of the block are modified. For example, use a base pointparameter if you want the base point of the block to always remain at thelower-left corner of a rectangle, even if that corner is stretched to a newposition.

Drawing features in Auto Cad

Different types of Drawing features

• Line

• Circle

• Arc

• Pline

• Spline

• Array

LINE • Line : It is used to create single straight line segment or series of line

segments.

• Select the line option from the home bar or you can give directcommand for starting your drawing.

COMMANDS

oLINE

oLINETYPE

oLINEWEIGHT

CIRCLE• It is a simple closed shape, as a series of points in a plane.

• Select the circle option form the home bar or give direct command tocreate a circle.

Various options to drawing a circle :

oCenter, Radius

o2 point

o3 point

oTangent, Tangent, Tangent

Command : CIRCLE

ARC

• Arc can be drawn by specify combination of center, endpoint,start point, radius, angle, chord length, and direction values.

• Arcs are drawn in a counterclockwise direction by default. Holddown the Ctrl key as you drag to draw in a clockwise direction.

Various options to drawing a arc :

o3-point

oStart, center, end

oContinuous

command: ARC

PLINE

• PLINE (Command) Creates a 2D polyline, a single object that iscomposed of line and arc segments. A 2D polyline is a connectedsequence of segments created as a single planar object. You cancreate straight line segments, arc segments, or a combination of thetwo.

SPLINE

• A spline is a smooth curve that passes through or near a set of points that influence the shape of the curve.

ARRAY

• The ARRAY Command allows you to create duplicates of existing objects in a rectangular or circle (polar) pattern.

EXAMPLE

Thanking you