ENGINEERING GRAPHICS AND DESIGN.pdf

JOIN telegram t.me/CSVTUEXAM t.me/csvtuexam JOIN telegram t.me/CSVTUEXAM ENGINEERING GRAPHICS & DESIGN  UNIT­ 1 JOIN telegram t.me/CSVTUEXAM Drawing: 2D or 3D views of an object without the purpose of manufacturing. It can be done manually or with the aid of a computer. Enginee...

JOIN telegram t.me/CSVTUEXAM t.me/csvtuexam JOIN telegram t.me/CSVTUEXAM ENGINEERING GRAPHICS & DESIGN  UNIT­ 1 JOIN telegram t.me/CSVTUEXAM Drawing: 2D or 3D views of an object without the purpose of manufacturing. It can be done manually or with the aid of a computer. Engineering Drawing: 2D or 3D views of an object with the purpose of manufacturing it. It can be done manually. Engineering Graphics: 2D or 3D views of an object with the purpose of manufacturing it. It is done with the aid of a computer.  Engineering Drawing ❑ It is a graphical means of expression of technical details without the barrier of a language. ❑ Universal language for Engineers. ❑ Graphical representation of an object to communicate product design and manufacturing information in a reliable and unambiguous manner. Drawing of an object contains all the necessary information, required for the construction/fabrication of the object, like actual shape, accurate sizes, manufacturing methods, materials to be used etc.,  DRAWING STANDARDS ❑ Drawing standards are a set of rules that governs how technical drawings are represented. ❑ Drawing standards are used so that drawings convey the same meaning to everyone who reads them. Standard code for Drawing S.No. Country Code Full Name 1. USA ANSI American National standard Institute 2. Japan JIS Japan Industrial Standard 3. UK BS British Standard 4. Australia AS Austrailian Standard 5. Germany DIN Deutsches Institut fur Normung 6. India ISO International Standards Organization DRAWING INSTRUMENTS S.No. Item Qty 1. Sketch Book (A3 size) 1 2. Drawing instrument Box (Large and 1 small size compass, large and small size divider etc. ) 3. Roller scale or Roll­n­drawn 1 (Big size, 30cm) 4. Scales 1 (Big size, 30cm) 5. French curves 1 6. Set­squares ­ 45° and 30° ­ 60° 1 set 7. Protractor 1 8. Drawing Pencils 3H/4H,2H,H,HB 9. Eraser (Rubber) 1 10. Tissue paper 1 11. Pencil sharpener 1 12. Pro circle 1 DRAWING BOARD DRAWING SHEET DRAWING INSTRUMENT BOX PROTRACTOR & PRO CIRCLE ROLLER SCALE DRAWING SHEET LAYOUT TITLE BLOCK LINES LINE TYPES LINE TYPES  DRAWING PENCILS S.No. Pencil Grade 1. Hard Pencil 9H,8H,7H,6H,5H,4H 2. Medium grade Pencil 3H,2H,H,F,HB,B 3. Soft Pencil 7B,6B,5B,4B,3B,2B  DRAWING PENCILS S.No. Pencil Lines 1. 3H/4H Centre line, section line 2. 2H Dimension line, dimensioning, arrowhead, outline, dotted line, free hand drawing, projecting, extending etc. 3. H Initial work and construction line 4. HB Writing purpose, continuous thick border line, letter writing , making notes DIMENSIONING DIMENSIONING TERMS AND NOTATIONS DIMENSIONING TERMS AND NOTATIONS SPACING OF DIMENSIONS PLACING OF DIMENSIONING / DIMENSIONING SYSTEM If you see 60 from right side only zero will be visible and 6 will be hidden  GENERAL RULE FOR DIMENSIONING (8 ) (9 ) PRACTICAL HINTS ON DIMENSIONING CYLINDRICAL DIMENSIONING HOLE DIMENSIONING ARC DIMENSIONING DIMENSIONING EXERCISE  LETTERIN ❑ Writing of titles, dimensions, notesGand other important particulars on a drawing is called lettering. ❑ Lettering is an important part of engineering drawing. It gives information regarding size, and instructions in the form of notes and dimension. On a drawing whole of the written information is always in the form of lettering. ❑ Writing text on a drawing (e.g. titles, dimensions, scales) using letters which can be alphabets, numerals, symbols to convey detailed information is called lettering.  Types of Lettering The two types of lettering as per the stroke are: 1.Single Stroke Lettering. 2.Double Stroke Lettering / Gothic letters/ Bold letter 1. Single stroke lettering ‐ Thickness of the line of the letter should be such as is obtained in one stroke of the pencil. The word single‐stroke should not be taken to mean that the letter should be made in one stroke without lifting the pencil. The Bureau of Indian Standards (IS : 9609‐2001) recommends single‐stroke lettering for use in engineering drawing. These are the simplest forms of letters and are usually employed in most of the engineering drawings. Basic strokes  Types of Single Stroke Lettering The two types of Single Stroke Lettering are: 1. Single Stroke vertical Lettering. (90° to horizontal) 2. Single Stroke Inclined Lettering. (75° to horizontal) 1. Single stroke vertical capital letter 2. Single stroke inclined capital letter Single­stroke lower­case letters are usually used in architectural drawings. Vertical and inclined lower­case alphabets are shown in figures 3 & 4 respectively. The width of the majority of letters is equal to the height. 3. Single stroke vertical small letter 4. Single stroke inclined small letter 2. Gothic letters / Double stroke lettering ­ When more thickness is given to single stroke letters, it is known as double stroke or gothic letters. The thickness of the stem may vary from 1/5 to 1/10 of the height of the letters. Figure given below shows the alphabet and figures in gothic with thickness equal to 1/7 of the height.  Types of Lettering The size of letters is described by its height. According to height of the letter, they are classified as: 1. Lettering ‘A’ 2. Lettering ‘B’ Lettering ‘A’ ‐ Height of capital letter is divided into 14 parts Lettering ‘B’ ­ Height of capital letter is divided into 10 parts Both types can be Vertical or Inclined at 75˚ to the horizontal Line Width of Type A ˂ Type B value Specifications h Height of uppercase (capital) letter a Height of lowercase (small) letter b Line thickness c Spacing between characters d Spacing between words e Spacing between base lines In lettering 'A' type, the height of the capital letter is divided into 14 parts, while in lettering 'B' type it is divided into 10 parts. The height of the letters and numerals for engineering drawing can be selected from 2.5, 3.5, 5, 7, 10, 14 and 20 mm according to the size of drawing. The ratio of height to width varies but in case of most of the letters it is 6 : 5 or 7:4 Lettering is generally done in capital letters. Different sizes of letters are used for different purposes. Example: h:w = 7:4 (22 alphabets), 7:1 for I, 7:3 for J, 7:5 for M and 7:6 (top) / 7:5 (bottom) for W h/w =7/4 so w = 4 means height of capital letter is 7 horizontal line or 7 vertical box and width of capital letter is 4 vertical line or 4 horizontal box.  Size of items on a Drawing S.No. Items on a Drawing Size(mm) 1. Name of the company, 10 ­ 12 Drawing numbers in the title block 2. Main titles of the drawing 6­8 3. Sub­titles of the drawing 3­6 4. Dimension figures, notes etc 3­5  Important Notes All letters should be uniform in shape, slope, size, shade and spacing. The shape and slope of every letter should be uniform throughout a drawing. For maintaining uniformity in size, thin and light guide­lines may first be drawn, and lettering may then be done between them. The shade of every letter must be the same as that of the outlines of drawings, i.e. intensely black. Therefore, H or HB grade of pencil is recommended for this purpose. The spacing between two letters should not necessarily be equal. The letters should be so spaced that they do not appear too close together or too much apart.  SCALES A scale is defined as the ratio of the linear dimensions of the object as represented in a drawing to the actual dimensions of the same. The proportion by which the drawing of a given object is enlarged or reduced is called scale of the drawing. It is not convenient, always, to draw drawings of the object to its actual size. e.g. Buildings, Heavy machines, Bridges, Watches, Electronic devices etc. Thus, following scales are used Enlarging scales Reducing scales Full scale Scales for the drawing of Scales for the drawing of Object is drawn on sheet to small objects needs to be huge objects needs to be its actual size, then its enlarged reduced drawn at full scale. Format – X:1, X>1, RF>1 Format – 1:Y, Y>1, RF Toolbars > AutoCAD > Modify from the menu bar. When you invoke the ERASE command, a small box, known as pick box, replaces the screen cursor. To erase an object, move the pick box so that it touches the object. Select the object by pressing the left mouse button, as shown in Figure. AutoCAD confirms the selection by changing the selected objects into dashed lines and the Select objects prompt returns. You can either continue selecting the objects or press ENTER to terminate the object selection process and erase the selected objects. To enter the command from the keyboard, type E or ERASE.  CANCELING AND UNDOING A COMMAND If you are in a command and you want to cancel or exit, press the ESC (Escape) key on the keyboard. Command: ERASE Select objects: Press ESC (Escape) to cancel the command. Similarly, sometimes you unintentionally erase some object. When you discover such an error, you can correct it by restoring the erased object by means of the OOPS command. The OOPS command restores objects that have been accidentally erased by the previous ERASE command, shown in figure. You can also use the U (Undo) command to undo the last command. Command: OOPS (Restores erased objects.) Command: U (Undoes the last command.) Use of the OOPS command  CUSTOMIZE USER INTERFACE (CUI) The CUI allows you to adjust the user interface and drawing area to match the way you work. Many of these settings are available from shortcut menus and the Options window. Some workspace elements, such as the presence and location of ribbon panels, and toolbars can be specified and saved using the Customize User Interface manager. For example Activate the workspace selection menu. a) Locate the Quick access menu up at the top left of the program window. b) Click on the Customize arrow and select Workspace. The Workspace pulldown menu will be added to the Quick access menu. Select the Drafting & Annotation workspace (if not already selected).  Drawing Entities / Draw Commands The Draw panel contains commands that allow you to draw standard geometries. The Draw commands can be used to create new objects such as lines and circles. To determine the name of the command associated with each icon in the Draw panel, place the cursor over each icon in turn and the associated command name will pop up and then in a few seconds an extended tooltip will appear.  Drawing Tools / Drawing Entities / Draw Commands The Draw panel contains commands that allow you to draw standard geometries. The Draw commands can be used to create new objects such as lines and circles. To determine the name of the command associated with each icon in the Draw panel, place the cursor over each icon in turn and the associated command name will pop up and then in a few seconds an extended tooltip will appear.  1. Draw Commands: LINE (L) A line is specified by giving its two endpoints. The LINE command can be used to draw a single line or a series of lines with the end­point of one being the start point of the next. When a series of such lines is created, each line is treated as a separate entity. To create a closed polygon, the user has to type in C (close option) for the To point: prompt. This causes the last and the first points to be joined by a line and thus creating a closed boundary. UNIT­ 4  The Undo Option in line Command If you draw a line, and then realize that you made an error, you can remove the line using the Undo option of the LINE command. If you need to remove more than one line, you can use this option multiple times and go as far back as you want. In this option, you can type Undo (or just U) at the Specify next point or [Undo] prompt. You can also right­click to display the shortcut menu, which gives you the Undo option. The following example illustrates the use of the Undo option. Removing lines using the Undo option of the LINE command  Special Function Keys 1. ESC­ Cancels the current command, menu, or dialog box. 2. ENTER­ Ends a command; or will repeat the previous command if the command line is blank. 3. SPACE BAR­ Same as the enter key except when entering text. Q.1 Draw and write the AutoCAD coding of a line diagram as shown in figure. Use Relative Polar Coordinate Method. 1. Command: UNITS or UN 2. 3. 4. Save the file in DWG format.  2. Draw Commands: CIRCLE (C) There are many ways of drawing a circle, the default being the centre point of circle and radius. Either on typing the command CIRCLE or selecting it from a menu bar with the help of mouse, all circle drawing options are displayed. The options available are: 1) Center point and Radius 2) Center point and Diameter 3) 3P: This specifies 3 points on the circumference of a circle. There is a unique circle passing through three given non­collinear points. 4) 2P: This specifies the end­points of diameter of a circle. 5) TTR (Tangent Tangent Radius): This command draws a circle of specified radius that is tangent to two lines, circles or arcs. 6) TTT (Tangent Tangent Tangent): This command draws a circle tangent to three entities.  (1) The Center and Radius Option Using this option, you can draw a circle by defining the center and the radius of the circle, as shown in Figure. After entering the CIRCLE command, AutoCAD will prompt you to enter the center of the circle, which can be selected by specifying a point on the screen or by entering the coordinates of the center point. Next, you will be prompted to enter the radius of the circle. For example: drawing a circle with a center at 3,2 and a radius of 1 unit.  (2) The Center and Diameter Option Use this option to draw a circle by defining its center and diameter. After using the CIRCLE command, AutoCAD prompts you to enter the center of the circle, which can be selected by specifying a point on the screen or by entering the coordinates of the center point. Next, you will be prompted to enter the radius of the circle. At this prompt, enter D. After this, you will be prompted to enter the diameter of the circle.  (3) The Two­Point Option You can also draw a circle using the Two­Point option. In this option, AutoCAD lets you draw the circle by specifying the two endpoints of the circle’s diameter. For example, if you want to draw a circle that passes through the points (1,1) and (2,1), you can use the CIRCLE command with 2P option.  (4) The Three-Point Option You can use this option to draw a circle by defining three points on its circumference. The three points may be entered in any order. To draw a circle that passes through the points (3,3), (3,1), and (4,2).  (5) The Tangent Tangent Radius Option A tangent is an object (line, circle, or arc) that contacts the circumference of a circle at only one point. In this option, AutoCAD uses the Tangent object snap to locate two tangent points on the selected objects that are to be tangents to the circle. Then you have to specify the radius of the circle.  (6) The Tangent, Tangent, Tangent Option To use this option, click on the down arrow on the right of the Center, Radius tool in the Draw panel of the Ribbon; a flyout will be displayed. Choose the Tan , Tan, Tan option from it. In this option, AutoCAD uses the Tangent Object Snap to locate three points on the three selected objects to which the circle is drawn tangent.  USE OF LINE AND CIRCLE COMMAND Use absolute, relative rectangular, or relative polar coordinates for drawing the triangle. The vertices of the triangle will be used as the center of the circles. The circles can be drawn using the Center and Radius, Center and Diameter, or Tan, Tan, Tan options.  IMPORTANT FUNCTION KEYS ❑ F1 ­ HELP ❑ F2 ­ FLIPSCREEN (AutoCAD Coding) ❑ F3 ­ OSNAP ON/OFF ❑ F7 ­ GRID ON/OFF ❑ F8 ­ ORTHO ON/OFF ❑ F9 ­ SNAP ON/OFF ❑ F10 ­ POLAR TRACKING ON/OFF ❑ F12 ­ DYNAMIC INPUT MODE ON/OFF  3. Draw Commands: POLYLINE OR PLINE (PL) POLY means “many”. This signifies that a polyline can have many lines. Polylines can include both lines and arcs connected at end­points. Thus, a polyline is a single entity with multiple segments. The polylines can be straight or curved, can be wide (like a TRACE) or tapered. Fillets and chamfers can be added where needed on a polyline. Curve fitting and hatching can easily be performed on a polyline. The PLINE command functions fundamentally like the LINE command, except that additional options are provided and all the segments of the polyline form a single object.  Width You can change the current polyline width by entering W (width option) at the last prompt. Next, you are prompted to specify the starting and ending width of the polyline. 1. FOR UNIFORM WIDTH POLYLINE The starting width value is taken as the default value for the ending width. Therefore, to have a uniform polyline, you need to press ENTER at the Specify ending width prompt. To draw a uniform polyline, shown in Figure, with a width of 0.25 units, start point at (4,5), endpoint at (5,5), and the next endpoint at (3,3), use the following prompt sequence: 2. FOR TAPERED POLYLINE You can get a tapered polyline, by entering two different values at the starting width and the ending width prompts. To draw a tapered polyline, shown in Figure, with a starting width of 0.5 units and an ending width of 0.15 units, a start point at (2,4), and an endpoint at (5,4), use the following prompt sequence: Arc This option is used to switch from drawing polylines to drawing polyarcs, and provides you the options associated with drawing polyarcs. The prompt sequence is given next. Angle This option prompts you to enter the included angle for the arc. If you enter a positive angle, the arc is drawn in a counterclockwise direction from the start point to the endpoint. If the angle specified is negative, the arc is drawn in a clockwise direction. The prompts are given next. Center refers to the center of the arc segment, Radius refers to the radius of the arc, and Endpoint draws the arc. Width This option prompts you to enter the width of the arc segment. To draw a tapered arc segment, you can enter different values at the starting width and ending width prompts. The prompt sequence is identical to that of the polyline. The following is the prompt sequence for drawing an arc, shown in Figure 3­47, with start point at (3,3), endpoint at (3,5), starting width of 0.50 units, and ending width of 0.15 units. Note If FILL is on or if FILLMODE is 1, the polylines drawn are filled. If you change FILL to off or FILLMODE to 0, only the outlines are drawn for the new plines and previously drawn plines are also changed from filled to no­fill. However, note that the change is effective only on regeneration. Similarly, it works in reverse also.  USE OF PLINE COMMAND The Undo option is particularly useful. This allows you to unpick polyline vertices one at a time so that you can easily correct mistakes. Also, polylines may be edited after they are created using the command PEDIT.  POLYEDIT / PEDIT/ PE COMMAND It is used to convert lines in to polyline. Before After PEDIT Command: PE (PEDIT) Select polyline or [Multiple]: Object selected is not a polyline Do you want to turn it into one? Y Enter an option [Close/Join/Width/Edit vertex/Fit/Spline/Decurve/Ltype gen/Reverse/ Undo]: J Select objects: 1 found Select objects: 1 found, 2 total Select objects: 2 segments added to polyline Enter an option [Open/Join/Width/Edit vertex/Fit/Spline/Decurve/Ltype gen/Reverse/Undo]: *Cancel* NOTE: we can also use Join or Region command to make different line in to ingle sigment for the same diagram. 4. Draw Commands: CONSTRUCTION LINE or XLINE (XL) The construction line (XLINE) command creates a line of infinite length which passes through two picked points. Construction lines are very useful for creating construction frameworks or grids. Construction lines are not normally used as objects in finished drawings. Therefore, it is usual to draw all your construction lines on a separate layer which will be turned off or frozen prior to printing. Because of their nature, the ZOOM EXTENTS command ignores construction lines. Point If you use the default option, AutoCAD will prompt you to select two points through which the xline shall pass at the Specify a point and the Specify through point prompts. After you select the first point, AutoCAD will dynamically rotate the xline through the specified point, as you move the cursor. When you select the second point, an xline will be created that passes through the first and second points. You can continue to select more points to create more xlines. All these xlines will pass through the first point you had selected at the Specify a point prompt. This point is also called the root point. Horizontal This option will create horizontal xlines of infinite length that pass through the selected points. The xlines will be parallel to the X axis of the current UCS. Vertical This option will create vertical xlines of infinite length that pass through the selected points. The xlines will be parallel to the Y axis of the current UCS. Angular This option will create xlines of infinite length that pass through the selected point at a specified angle. The angle can be specified by entering a value at the keyboard. You can also use the reference option by selecting an object and then specifying an angle relative to it. The Reference option is useful, when the actual angle is not known but the angle relative to an existing object can be specified. Bisect This option will create an xline that passes through the angle vertex and bisects the angle you specify by selecting two points. The xline created using this option will lie in the plane defined by the selected points. You can use the object snaps to select the points on the existing objects. Offset The Offset option creates xlines that are parallel to the selected line/xline at a specified offset distance. You can specify the offset distance by entering a numerical value or by selecting two points on the screen. If you select the Through option, the offset line will pass through the selected point. This option works like the OFFSET editing command. The prompts at the command line are as follows. If you specify the offset distance, and after you have selected a line object, you are prompted to specify the direction in which the xline is to be offset.  5. Draw Commands: RAY The RAY command creates a line starting at a point and going off to infinity through another specified point. The through point: prompt is repeated allowing you to create multiple rays. Because of their nature, the ZOOM EXTENTS command ignores rays. UNIT­ 5 3D MODELING USNG CAD SOFTWARE  3D MODELING AND ITS ADVANTAGES 3D modeling is a technique in computer graphics for producing a 3D digital representation of any object or surface. 3D models have the following advantages. 1. To generate the drawing views. Once you have created the 3D model, its 2D drawing views can be automatically generated. 2. To provide realistic effects. You can provide realistic effects to the 3D models by assigning a material and providing light effects to them. For example, an architectural drawing can be made more realistic and presentable by assigning the material to the walls and interiors and adding lights to it. 3. To create the assemblies and check them for interference. You can assemble various 3D models and create the assemblies. Once the components are assembled, you can check them for interference to reduce the errors and material loss during manufacturing. 4. To create an animation of the assemblies. You can animate the assemblies and view the animation to provide the clear display of the mating parts. 5. To apply Boolean operations. You can apply Boolean operations to the 3D models. 6. To calculate the mass properties. You can calculate the mass properties of the 3D models. 7. Cut Sections. You can cut sections through the solid models to view the shape at that cross­section.  TYPES OF 3D MODELING In AutoCAD the 3D models are divided into the following three categories. 1) Wireframe Models (2) Surface Models (3) Solid Models (1) Wireframe Models: These models are created using simple AutoCAD entities such as lines, polylines, rectangles, polygons, or some other entities such as 3D faces, and so on. To understand the wireframe models, consider a 3D model made up of match sticks or wires. These models consist of only the edges and hence you can see through them. You cannot apply the Boolean operations on these models and cannot calculate their mass properties. Wireframe models are generally used in the bodybuilding of the vehicles. Wireframe modeling is the simplest of all modeling techniques based on edges, vertices, and faces. Wireframe modeling suffers from uniqueness and ambiguity issues. (2) Surface Models In this modeling the objects are created by use of surfaces attached to 3D Wireframe models. The attached surfaces have zero thickness so cannot calculate the mass properties. It can hide objects that are behind them. These models are just empty shells. The surfaces are flat, with curved and rounded surfaces approximated by small rectangular or triangular faces. These models are made up of one or more surfaces. They have a negligible wall thickness and are hollow inside. To understand these models, consider a wireframe model with a cloth wrapped around it. You cannot see through it. These models are used in the plastic molding industry, shoe manufacturing, utensils manufacturing, and so on. You can directly create a surface or mesh. Alternatively, you can create wireframe model and then convert it into a mesh or surface model. Remember that you cannot perform Boolean operations in the surface models. Surfaces define the shape of a hollow model. Surface modeling gives designers a great amount of control and flexibility. (3) Solid Models Solid modeling is the process of building objects that have all the attributes of an actual solid object. It has mass, weight, volume, center of gravity, moment of inertia etc, in addition to surfaces and edges. We can cut, join and create holes and cavities. It is a single object and are used as a part to create assemblies and interference check. These are the solid filled models having mass properties. To understand a solid model, consider a model made up of metal or wood. You can perform the Boolean operations on these models, cut a hole through them, or even cut them into slices.  3D MODELING USING AutoCAD In AutoCAD, you can start the 3D Modeling in a separate workspace (3D Modeling). All commands and options required to create the 3D design are displayed in this workspace. You can switch between the 2D Drafting & Annotation workspace and the 3D Modeling workspace using the Workspace Switching button available at the bottom right corner of the Status Bar. There are 3 tabs on top left side On working window: View Cube 1. Viewport controls 2. View controls 3. Visual style controls Navigation Bar 1. Viewport controls 2. View controls 3. Visual style controls  Basic Primitives / Solid Modeling Primitives The simplest solid objects used for the representation are called primitives. The Solid primitives form the basic building blocks for a complex solid. There are seven predefined solid primitives that can be used to construct a solid model such as Box, Wedge, Cone, Cylinder, Pyramid, Sphere, and Torus.  1. BOX You can use the BOX command to create a solid rectangular box or a cube. The methods to create a solid box are: 1. Two Corner Option: This is the default option using which you can create a solid box by defining the first corner of the box and then its other corner. Note that the length of the box will always be taken along the X axis, the width along the Y axis, and the height along the Z axis. Therefore, in this case, when you specify the other corner, the value along the X axis will be taken as the length of the box and the value along the Y axis will be taken as the width of the box. Next, you will be prompted to specify the height of the box. 2. Center­Length Option: The center of the box is the point where the center of gravity of the box lies. This option is used to create a box by specifying the center of the box as well as the length, width, and height of the box. 3. Corner­Cube Option This option is used to create a cube starting from a specified corner as shown in figure. You are creating a cube, and so you will be prompted to enter the length of the cube.  2. CONE The CONE command creates a solid cone with an elliptical or circular base. This command provides you with the option of defining the cone height or the location of the cone apex. Defining the location of the apex will also define the height of the cone and the orientation of the cone base from the XY plane. 1. Circular Cone: This method is used to create a cone with a circular base. Specify the center point and the radius of the base. Next, specify the height of cone by moving the cursor away from the base.The options for defining the circular base are Center Radius, Center Diameter, 3 Point, 2 Point, and Tangent Tangent Radius. 2. Axis endpoint option To specify the height using the Axis endpoint option, choose Axis endpoint from the shortcut menu. 3.Top radius option: If you want to create a frustum of a cone, choose the Top radius option from the shortcut menu, at the Specify height or [2Point/Axis endpoint/Top radius] prompt. After specifying the base radius, specify the radius of the top circle, The prompt sequence is as follows:  4. Elliptical Cone option Using this method, you can create a cone that has an elliptical base. To create an elliptical cone, choose the Elliptical option from the shortcut menu, at the Specify center point for base of cone or [3P/2P/Ttr/Elliptical] prompt. You will be prompted to create the base ellipse for the cone. You can create it using any of the methods for drawing the ellipse. However, you cannot specify the rotation, in this case, for defining the other axis. You need to specify the length of the other axis. Once you have entered all these values, you will be prompted to specify the cone height or choose from the 2point, Axis endpoint, and Top radius. The procedure to create an elliptical cone using these options is similar to the procedure used to create a circular cone.  3. CYLINDER You can use the CYLINDER command to create a solid cylinder. Similar to the CONE command, this command provides you with two options for creating the cylinder: circular cylinder and elliptical cylinder. This command also allows you to define the height of the cylinder or choose from the 2Point or Axis endpoint options. 1.Circular Cylinder: This option is used to create a cylinder with a circular base.This circular base can be defined by using the Center Radius, Center Diameter, 3Point, 2Point, or Tangent Tangent Radius options. Creating a circular cylinder You can also create an inclined cylinder by specifying the center of the other end. This is done by entering C at the Specify height or [2 Point/Axis endpoint] prompt. Specifying the center of the other end 2. Elliptical Cylinder This option is used to create a cylinder with an elliptical base. The elliptical cylinder can be created by choosing the Elliptical option from the shortcut menu Creating an elliptical cylinder Specifying the center of the other end  4. SPHERE The SPHERE command is used to create a solid sphere, To create a sphere, you will be prompted to specify the center of the sphere. On specifying the center, you can create the sphere by defining its radius or diameter. Instead of specifying the center of the sphere, you can also specify its circumference by choosing any one of the 3P/ 2P/Ttr options. Specify center point or [3P/2P/Ttr]: Specify the location of the center of the sphere or choose an option. Specify radius of sphere or [Diameter]: Specify the radius or choose an option.  4. TORUS You can use the TORUS command to create a torus that is like the shape of tyre­tube, To create a torus, you will be prompted to enter the diameter or the radius of the torus and the diameter or the radius of Tube. The radius of torus is the distance from the center of the torus to the center line of the tube. This radius can have a positive or a negative value. If the value is negative, the torus has a rugby­ball like shape. A torus can be self­intersecting. If both the radii of the tube and the torus are positive and the radius of the tube is greater than the radius of the torus, the resulting solid looks like an apple (Figure 26­19). Instead of specifying the radius or diameter of the torus, you can also specify the points through which the circumference of the torus will pass by choosing any one of 3P, 2P, or Ttr options. Torus with a negative radius value Torus with radius of tube more than the radius of torus Torus created dynamically Parameters associated with a torus  6. WEDGE This command is used to create a solid wedge and is similar to the BOX command. This means that this command provides you with the options of creating the wedge that is similar to those of the BOX command. 7. PYRAMID The Pyramid option allows you to create a solid pyramid where all the faces, other than the base, are triangular and converge at a point called apex.The base of a pyramid can be any polygon, but is typically a square. Command: _pyramid 4 sides Circumscribed Specify center point of base or [Edge/Sides]: Specify the center point. Specify base radius or [Inscribed] : Specify the base radius. Specify height or [2Point/Axis endpoint/Top radius] : Specify the height to create the pyramid, On invoking the PYRAMID command, you can specify the center point of the base polygon or the length of the edges, or the number of sides of the polygon. If you select the Edge option in the command window, you will be prompted to pick two points from the drawing area that determine the length and orientation of the edge of the base polygon. If you select the Sides option, you will be prompted to specify the number of sides of the base polygon. Note that in AutoCAD, the number of sides of a pyramid can vary from 3 to 32. Next, you need to specify the base radius of the circle in which the base polygon is created. The base polygon is either circumscribed around a circle or inscribed within a circle. By default, the base of the pyramid is circumscribed. After specifying the base radius, you need to specify the height of the pyramid or select an option