1 Computer Aided Engineering Drawing Editing Tools in AutoCAD Chapter No 4 Sir Syed University of...

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Computer Aided Engineering Drawing

Editing Tools in AutoCAD

Chapter No 4

Sir Syed University of Engineering & TechnologyComputer Engineering Department University Road, Karachi-75300, PAKISTAN

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CAED - Chapter No 4 Editing Tools in AutoCAD

Text Book

Text Book: Mastering AUTOCAD 14

By George Omura

Course Outline is available at CAED course website.

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Chapter Outline

Erase Oops Copy Move Fill Rotate Divide Measure Block

Scale Mirror Stretch Extend Offset Fillet Chamfer Array

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Erase Command

The ERASE command lets you delete selected entities from the drawing. Format: ERASE Select objects:

You can easily erase just the last object you drew by responding to the "Select objects" prompt with "L". You can erase the previous selection set by responding with "P".

The OOPS command can also be used to retrieve the last thing you erased.

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Erase Command

Modify / Erase Submenu

Select Erases multiple selected objects. Single Erases a single selected object. Last Erases the last object created. Oops! Undoes the last Erase command.

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OOPS Command

The OOPS command reinserts the object(s) deleted by the most recent ERASE or BLOCK command.

Format: OOPS

You can also use UNDO for a general method of reversing the effect of most commands

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Copy Command

The COPY command duplicates one or more existing drawing entities at another location (or locations) without erasing the original. Format: COPY Select objects: <Base point or displacement>/Multiple: first point

or

distance. Second point of displacement: Enter

second point

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Move Command

The MOVE command is used to move one or more existing drawing entities from one location in the drawing to another. Format: MOVE Select objects: Base point or displacement: Select a

point or enter a

displacement vector.

Second point of displacement: Select a point.

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Fill Command

The FILL command controls whether Solids, Traces, and wide Polylines are to be solid-filled or just outlined. Format: FILL ON/OFF <current>:

Controls the filling of multilines, traces, solids, solid-fill hatches, and wide polylines

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Rotate Command

The ROTATE command can be used to rotate existing entities. Format: ROTATE Select objects: Base point: Enter a point. <Rotation angle>/Reference:

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Rotate Command

f you respond to the <Rotation angle>/Reference: prompt with a numeric angle, this is taken as a relative angle (number of degrees) by which the selected objects will be rotated about the specified base point, from their current orientation.

A positive angle produces counterclockwise rotation; a negative angle produces clockwise rotation. If you respond to the last prompt with R, you can specify the current rotation and the new rotation you want. AutoCAD prompts: Rotation angle <0>: New angle:

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Divide Command

The DIVIDE command lets you divide an entity into a specified number of equal length parts, placing markers along the objects at the dividing points.

Format: DIVIDE Select object to divide: <Number of segments>/Block:

Valid objects that can be divided include arcs, circles, ellipses and elliptical arcs, polylines, and splines

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Divide Command

You can select a single Line, Arc, Circle, or Polyline. If you enter a segment count within the valid range of 2 through 32,767, Point entities are placed along the object to divide it into that number of equal segments.

You can request a specific Block to be inserted instead of the Point entities by responding to the second prompt with B. The system then prompts:

Block name to insert: Align block with object? <Y>: Number of segments:

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Measure Command

The MEASURE command allows you to measure an entity, placing markers along the object at intervals of the specified distance. Format: MEASURE Select object to measure: <Segment length>/Block:

Markers are always placed on the object, regardless of the elevation settings.

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Block Command

You can request a specific Block to be inserted instead of the Point entities by responding to the second prompt with B. AutoCAD then prompts:

Block name to insert: Align block with object? <Y> Segment length:

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Block Command

The Block must currently be defined within the drawing. If you answer Y to the Align block with object? prompt, the Block is rotated around its insertion point, and drawn tangent to the object being measured.

After you answer these prompts, AutoCAD measures the object, drawing the specified Block where each pair of segments meet.

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Scale Command

The SCALE command lets you change the size of existing entities. The same scale factor is applied to X and Y dimensions. Format: SCALE Select objects: Base point: Select a point. <Scale factor>/Reference: Enter a number or R.

If you respond to the <Scale factor>/Reference: prompt with a number, this is taken as a relative scale factor by which all dimensions of the selected objects will be multiplied.

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Scale Command

To enlarge an object, enter a scale factor should be greater than 1.To shrink an object, use a scale factor between 0 and 1.

If you respond to the <Scale factor>/Reference: prompt with R, you can specify the current length and the new length you want. AutoCAD prompts: Reference length <1>: New length:

Indicate the Reference length by pointing to the two endpoints of a line to be scaled. Specify the new length by pointing, or by dragging the object.

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Mirror Command

The MIRROR command lets you mirror selected entities in your drawing. The original objects can be deleted (like a MOVE) or retained (like a COPY). Format: MIRROR Select objects: First point of mirror line: Enter a point. Second point:: Enter a point. Delete old objects? <N>: Enter Yes, No, or press .

The mirror line you designate is the axis about which the selected objects are mirrored; it can be at any angle.

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Stretch Command

The STRETCH command allows you to move a selected portion of a drawing, preserving connections to parts of the drawing left in place. Connections made with Lines, Arcs, Traces, Solids, Polylines, and 3D Faces can be stretched. Format: STRETCH Select objects to stretch by window... Select objects:

While you may use any of AutoCAD's forms of object selection in the STRETCH command, you must use a window-style selection, either Crossing or Window, at least once.

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Stretch Command

The last window specified will be the window moved by STRETCH. Objects can be freely added and removed from the selection set. Once the selection set is specified, STRETCH asks you: Base point: New point:

And displays a rubber-band line attached to the base point you enter. After you pick the new point, all the chosen objects will be moved or stretched as appropriate. STRETCH behaves differently depending on the entity type it is examining.

Endpoints of Lines, which fall within the box, are moved; endpoints outside the box are left unchanged.

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Extend Command

The EXTEND command lets you lengthen existing objects in a drawing so that they end precisely at a boundary defined by one or more other objects in the drawing. Format: EXTEND Select boundary edge(s)... Select objects: <Select object to extend>/Undo:

You can use any form of entity selection to define the boundary objects. Lines, Arcs, Circles, and 2D Polylines can serve as boundary objects.

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Offset Command

The OFFSET command constructs an entity parallel to another entity at either a specified distance or through a specified point. You can offset a Line, Arc, Circle, or 2D Polyline. Format: OFFSET Offset distance or Through <last>: Select object to offset:

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Offset Command

To offset from a wide 2D Polyline, measure the offset distance from the centerline of the Polyline. Once the object is selected, it is highlighted on screen.

Depending on whether you specified an offset distance or selected Through in the original prompt, you receive one of the following prompts: Side to offset: or Through point:

The offset is then calculated and drawn. The selected object is de-highlighted and the Select object to offset: prompt reappears. Press to exit the command.

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Fillet Command

The FILLET command connects two lines, arcs, or circles with a smooth arc of specified radius. It adjusts the lengths of the original lines or arcs so they end exactly on the fillet arc.

The FILLET command rounds or fillets the edges of two arcs, circles, elliptical arcs, lines, polylines, rays, splines, or xlines with an arc of a specified radius.

Format:FILLET

Polyline/Radius/<Select first object>: Enter P or R or Select two entities to fillet.

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Fillet Command

Options

Polyline Fillets an entire Polyline, or those segments to which the current radius can apply.

Radius Sets the fillet radius for subsequent FILLET commands.

Select... Allows you to select a first and second Line, Arc, Circle, or Polyline segment.

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Chamfer Command

The CHAMFER command trims two intersecting lines (or two adjacent segments of a Polyline) at a given distance from their intersection and connects the trimmed ends with a new line.

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Chamfer Command

Different trim distances can be set for the two lines, and are retained with the drawing. If the specified lines do not intersect, CHAMFER extends them until they do, and then proceeds as above.

Format: CHAMFER Polyline/Distances/<Select first line>:

Options P Chamfers entire Polyline. D Sets chamfer distances.

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Array Command

The ARRAY command makes multiple copies of selected objects, in a rectangular or circular pattern.

Format: ARRAY Select objects: Show what

to copy. Rectangular or Polar array (R/P):

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Array Command

For a rectangular array, AutoCAD asks for the number of columns and rows, and the spacing between them. The array is built along a baseline defined by the current Snap rotation angle set by the SNAP Rotate command.

For a polar, or circular, array, you first supply a center point. Then you supply two of the following three parameters: The number of items in the array. The number of degrees to fill. The angle between items in the array. You can also rotate the items as the polar array is

drawn.

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Polar and Rectangular Array

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