engr graphics

ENGR 1204 Engineering Graphics

Lecture 4

Basic Object Commands

Dr. Joseph KamtoHCCS

Department of EngineeringEmail: [email protected]

Dr Kamto 1Pictures are from AutoCad and its

Applications Basic, 2015- 22nd edition. ENGR 1204

Basic Commands Draw circles using CIRCLE command options Draw arcs using ARC command options Use the ELIPSE command to draw ellipses and elliptical

arcs Use PLINE command to draw polylines Draw regular polygons using POLYGONE command Draw rectangles using RECTANGLE command Draw donuts and filled circles using DONUT command Draw true spline curves using SPLINE command

Dr Kamto 2Pictures are from AutoCad and its


Drawing Circles Many options based on information, access CIRCLE command and chose the appropriate

option from ribbon (quick)

Center Radius option to specify the center and the radius Use direct entry or drawing aids to locate the center Enter radius value, or locate radius with drawing aids Press [Enter]

Center Diameter option to specify the center and the diameter Use direct entry or drawing aids to locate the center Enter diameter value, or locate radius with drawing aids Press [Enter]

2- Point option to specify diameter using two points at opposite quadrants of the circle (center of the circle difficult to locate) Use direct entry or drawing aids to locate the first and second points

Dr KamtoPictures are from AutoCad and its


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Drawing Circles 3- Point option to draw a circle based on three known points on the circumference of

the circle (center, radius, diameter unknown) Use direct entry or drawing aids to locate the first , second and third points

Tan, Tan, Radius option to pick two objects tangent to a circle and the circle radius Hover over the first object and select when Deferred Tangent object snap market

shows Repeat on second object Type radius value

Tan, Tan, Tan option to pick two objects tangent to a circle and the circle radius Hover over the first object and select when Deferred Tangent object snap market

shows Repeat on second object Repeat on third object



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Drawing ArcsMany options based on information, access ARC command and chose the appropriate option from

ribbon (quick)

Use direct entry or drawing aids for radius value, diameter value angle value, first, second, third points Tangent direction depending of the options as seen on the picture

Hold down [ctrl] key while ARC command active to reverse direction of ARC drawing

Continue option to continue an arc from the endpoint of a previously drawn line, arc



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Drawing EllipsesEllipse has a major and a minor axis. A circle appears as an ellipse when view at an angleaccess ELLIPSE command and chose the appropriate option from ribbon (quick) Center option

Specify center Endpoint from center for first axis Endpoint from center for second axis

Axis, End option First endpoint for an axis Second endpoint for same axis Endpoint for second axis

Rotation option to specify the angle at which a circle rotate from line of sight Create major axis first endpoint at the first prompt Select Rotation at second prompt Enter the angle at which the circle rotate from line of sightRotation option work with Center and Axis, End options



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Drawing Elliptical Arcs

Use the ARC option of ELLIPSE command Similar to Axis, End ellipse

option Specify first and second

point of an axis, Specify one end point of the

second axis Select start and end angles

for the elliptical arc



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Drawing PolylinesUse PLINE to draw polylines. All segment of a polyline act as a single object. Default setting identical to LINE command Access PLINE from ribbon (quick) and use point entry or drawing aids to locate endpoints

PLINE command includes the UNDO, CLOSE options

Setting Polyline Width Default setting: constant width of 0 Access PLINE command

Pick first point and select Width Pick first point and select Width

Enter same value for starting and ending width to create constant width Enter different value for starting and ending width to create tapered like

arrowhead Specify width 0 to create a sharp end of an arrowhead



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Drawing Rectangular PolygonAccess POLYGONE command to draw any rectangular polygon with up to 1024 sides in a single polyline object

Enter the number of sides at first prompt

Specify the location of polygon center

Select inscribed or circumscribed polygon

Specify radiusUse EDGE option to draw polygon knowing only a single edge



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Drawing RectanglesUse RECTANGLE command to draw rectangle

Specify the point of one corner Specify the point of opposite corner

Select Chamfer option to add chamfered corner Enter first chamfer distance Enter second chamfer distance

Select Fillet option to add rounded corner Enter radius for rounds and fillets

Select Width option to adjust the rectangle line width

Select Area option to specify the surface and one side of the rectangle (available after picking the first corner) Width option to specify the width size Length option to specify the length size



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Drawing Rectangles Specifying Rectangle Dimensions

Select the Dimensionsoption to specify the next corner of the rectangle (available after picking the first corner point)

Drawing a rotated Rectangle Select Rotation option to

draw a rectangle at an angle other than 0. (available after picking the first corner)



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Drawing Donuts and Filled CirclesThe DONUT command allows to draw a thick or filled circle Access DONUT command

Specify the inside diameter Specify the outside diameter Use direct entry or drawing aids to locate the donut center Press [enter] or [Esc] to end the command



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Drawing True SplinesNURS curve or B-spline is a type of curve using non-uniform rational basis spline ( example of acontour of a site plan or drawing of anergonomic consumer product)Access SPLINE command

specify fit points using point entry or drawing aids Press [Enter] to create spline and end command

Use Close option to connect the last point to the first point



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Homework Drawing Problem #5 page 141, #7 page 142, #10 page 143 and

#16 page 117.

Drawing Problems #8 Page 142, #14 page 144, #17 page 145 and #19 Page 146.



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Slide Number 1Basic CommandsDrawing Circles Drawing Circles Drawing ArcsDrawing EllipsesDrawing Elliptical ArcsDrawing PolylinesDrawing Rectangular PolygonDrawing RectanglesDrawing RectanglesDrawing Donuts and Filled CirclesDrawing True SplinesHomework

engr graphics

Documents

circle center

center diameter option

tan option

center endpoint

access circle command

circle radius hover

appropriate option

drawing circles