Introduction to AutoCAD 2012

Transcription

1 Page 1 Introduction to AutoCAD 2012 Alf Yarwood Chapter 17 Exercise 1 1. Open AutoCAD 2012 with a double-click on its shortcut icon in the Windows desktop. 3. Use the two layers 0 and Cyan. 4. Set the variable UCSFOLLOW to At the command line: Command: enter ucs right-click Current ucs name: *WORLD* Enter an option [New/Move/orthoGraphic/Prev/Restore/Save/Del/Apply/?/World] <World>: enter g (for orthographic) right-click Enter an option [Top/Bottom/Front/BAck/Left/Right]<Top>: enter f (for Front) right-click Regenerating model. Command: 6. Zoom to Construct a closed polyline outline for the bracket and extrude to a height of 60. Note the external radius of the left-hand end of the bracket is Place in the ViewCube/Isometric view. Then, at the command line: Command: enter ucs right-click Current ucs name: *FRONT* Enter an option [New/Move/orthoGraphic/Prev/Restore/ Save/Del/Apply/?/World] <World>: enter n (for New) right-click Specify origin of new UCS or [ZAxis/3point/OBject/Face/ View/X/Y/Z] <0,0,0>: enter f (for Face) right-click Select face of solid object: pick the upper sloping face Enter an option [Next/Xflip/Yflip] <accept>: right-click unless the wrong face is highlighted, enter n (for Next) and continue if needed until correct face is chosen Regenerating model. Command: 9. The drawing area regenerates with the upper face as the new UCS. 10 Construct a cylinder for the hole into which the pin fits at 75 from the right-hand end of the face and subtract it from the face. Note the height of the cylinder is -15 (because the upper surface of the face is lying in the UCS plane). 11. Make the layer Cyan current and construct two cylinders for the pin that fits into the upper arm of the bracket. Note the negative numbers given to the heights of the cylinders in the following command line sequence. Command: _cylinder Current wire frame density: ISOLINES=4 Specify center point for base of cylinder or [Elliptical] <0,0,0>:.xy of pick centre of hole (need Z): enter -15 right-click Specify radius for base of cylinder or [Diameter]: enter 20 right-click Specify height of cylinder or [Center of other end]: enter -10 right-click Command: right-click CYLINDER Current wire frame density: ISOLINES=4

2 Page 2 Specify center point for base of cylinder or [Elliptical] <0,0,0>: enter.xy right-click of pick centre of hole (need Z): enter -15 right-click Specify radius for base of cylinder or [Diameter]: enter 15 right-click Specify height of cylinder or [Center of other end]: enter 30 right-click Command: 12. The two cylinders of the nut have now been constructed. Join the two cylinders to form a union. Command: _union Select objects: pick one of the cylinders 1 found Select objects: pick the other 1 found, 2 total Select objects: right-click Command: 13. Place the window in the UCS FRONT view to check the pin is correct and Zoom to Make the layer 0 current. 15. Place the drawing in the ViewCube/Isometric view, enter ucs at the command line and pick the bottom face. Construct the cylinder for the hole and subtract it from the bracket. 16. Make layer Cyan current and construct another nut in its position in the hole. 17. Place the drawing in the UCS WORLD. 18. Add suitable lighting and materials to the pins and bracket. 19. Place the drawing in the ViewCube/Isometric view and render. 20. Save the drawing with a file name 17_Exercise01.dwg to a memory stick. Chapter 17 Exercise 2 1. Open AutoCAD 2012 with a double-click on its shortcut icon in the Windows desktop. 3. Construct two concentric polygons each of six sides, the first of an edge length 46 and the second of an edge length Extrude the first polygon to a height of 60 and the second to a height of Set UCSFOLLOW to Place the drawing in the Front view, move the smaller extrusion to sit on top of the larger and form a union of the two solids. 7. Place the union in the ViewCube/Isometric view and enter ucs at the command line. Command: enter ucs right-click Current ucs name: *FRONT* Enter an option [New/Move/orthoGraphic/Prev/Restore/Save/Del/Apply/?/World] <World>: enter n (New) right-click Specify origin of new UCS or [ZAxis/3point/OBject/ Face/View/X/Y/Z] <0,0,0>: enter f (Face) right-click Select face of solid object: pick a face of the lower extrusion Enter an option [Next/Xflip/Yflip] <accept>: rightclick Regenerating model. Command:

3 Page 3 8. Zoom to On the face construct a polyline for the extended hole and extrude it to a height of -160 (higher than required). 10. Subtract the extrusion from the model. 11. Repeat steps 7 to 10 for the other two faces of the lower polygonal extrusion. 12. Repeat steps 7 to 10 for three of the faces of the upper of the polygonal extrusions, but this time construct cylinders on the faces of radius 15 and height 100 (again higher than necessary). 13. Add suitable lighting and a material. 14. Save the drawing with the file name 17_Exercise02.dwg to a memory stick. 15. Close the drawing window. Chapter 17 Exercise 3 1. Open AutoCAD 2012 with a double-click on its shortcut icon in the Windows desktop. 3. Set UCSFOLLOW to Construct the plan view of one of the flanges. Extrude the outer polyline and the R5 circles by 15. Subtract the circular extrusions from the outer extrusion. 5. Place the drawing in a new UCS using the 3point prompt. Command: enter ucs right-click Current ucs name: *WORLD* Enter an option [New/Move/orthoGraphic/Prev/Restore/Save/Del/Apply/?/World] <World>: enter 3 right-click Specify new origin point <0,0,0>: pick a point to the left of a line central to the extrusion Specify point on positive portion of X-axis <141,160,0>: pick a point to the right of the extrusion Specify point on positive-y portion of the UCS XY plane <140,161,0>: enter.xy right-click of pick the first point (need Z): enter 1 right-click Regenerating model. Command: right-click The extrusion regenerates in a new UCS central to the extrusion. 6. Zoom to Construct a quarter circle of radius 105 as a path for extrusions. 8. Place the drawing in the ViewCube/Isometric view and Zoom to Extrude the two circles for the pipe along the path of the quarter circle. 10. Place the drawing in the Front view. 11. Zoom to Copy the base and rotate the copy through 90. Then move the copy to its place at the end of the quarter circle path. 13. Place the drawing in the VieCube/Isometric view. 14. Form a union from the two flanges and the outer quarter circle extrusion and subtract the inner quarter circle extrusion from the union. 15. Place the drawing in the UCS WORLD and add suitable lighting. 16. Attach a material and render. 17. Save to a memory stick with the file name 17_Exercise03.dwg. 18. Close the drawing window.

4 Page 4 Chapter 17 Exercise 4 1. Open AutoCAD 2012 with a double-click on its shortcut icon in the Windows desktop. 3. Reset Limits to an A3 size (594 x 420) as follows: Command: enter limits right-click Reset Model space limits: Specify lower left corner or [ON/OFF] <0,0>: right-click Specify upper right corner <420,297>: enter 594,420 right-click Command: enter z right-click Specify corner of window, enter a scale factor (nx or nxp), or [All/Center/Dynamic/Extents/Previous/Scale/Window/Object] <real time>: enter a rightclick Command: 4. Set UCSFOLLOW to Set the UCS to FRONT and Zoom to On layer 0 construct the outline of the front view of the left-hand end of part of the arm and extrude to a height of 20. Subtract the hole from the arm. 7. Set the screen to the Top view and Zoom to Construct a polyline outline of the plan of the right-hand end of the arm and extrude to a height of Set the Front view, Zoom to 1 and move the right-hand end of the arm to its position at the end of the lefthand end. Form a union of the two parts. 10. Place in the ViewCube/Isometric view. Fillet the left-hand edges to a radius of 10 and the curves of the handle to a radius of 5 (using the Chain prompt of the Fillet command line sequence).

5 Page Make Red current. 13. In the Front view construct a polyline outline for a solid of revolution for the spindle. 14. Set ISOLINES to Form a solid of revolution for the spindle using the Revolve tool from the 3Home/3D Modeling panel. 16. Make layer 0 current and construct a cylinder for the hole in the arm to take the pin. 17. In the Front view move the hole and spindle to their correct positions in the arm and subtract the hole from the arm. 18. Make Magenta current, construct a pline outline for a solid of revolution of the pin and revolve. 19. Make Magenta current and construct outlines for the base. Extrude the curbed part to a height of 20 and the rectangular base to a height of In the Top view move the parts to their correct positions relative to each other. Construct cylinders for the holes in the base. 21. Go back to the Front view and move the holes to their correct places in the base. Union the two parts of the base and subtract the holes. 22. Place the drawing in the ViewCube/Isometric view and fillet the corners of the base plate to a radius of Go back to the Top view and add lights - a Point light above, a Distant light to the front and above, and another Distant light to the leftfront and above.

6 Page Place in the ViewCube/Isometric view and attach materials to the parts of the model. 25. Save the drawing in a memory stick with the file name 17_Exercise04.dwg. 26. Close the drawing window. Chapter 17 Exercise 5 1. Open AutoCAD 2012 with a double-click on its shortcut icon in the Windows desktop. 3. Construct a polyline outline for the base of the device, extrude all parts to a height of 7.5 and subtract the holes from the base. 4. Set UCSFOLLOW to At the command line: Command: enter ucs right-click Current ucs name: *WORLD* Enter an option [New/Move/orthoGraphic/Prev/ Restore/Save/Del/Apply/?/World] <World>: enter 3 right-click Specify new origin point <0,0,0>: pick a point to the left and central to the plan Specify point on positive portion of X-axis <116,170,0>: pick a point to the right and central to the plan Specify point on positive-y portion of the UCS XY plane <115,171,0>: enter.xy right-click of pick the first point (need Z): enter 1 right-click Regenerating model. Command: 6. Zoom to Set ISOLINES to On this new UCS plane which is central to the base construct a polyline for a solid of revolution for the upright part of the device and revolve the pline through Place the drawing in the ViewCube/Isometric view and Zoom to Union the two parts and fillet the join to a radius of Add lighting to the model and attach a material. 12. Render the model. 13. Save the drawing with the file name 17_Exercise05.dwg to a floppy disk. 14. Close the drawing window.

7 Page 7 Chapter 17 Exercise 6 1. Open AutoCAD 2012 with a double-click on its shortcut icon in the Windows desktop. 3. Set UCSFOLLOW to Place the AutoCAD drawing area in the Front view and construct an outline of the fork part of the connector and extrude to a height of Place in the Top view and construct two cylinders, one of radius 15 and height 50 and the other of radius 10 and height In the Front view move the two cylinders to their correct positions at the top of the fork. 7. Form a union between the fork and the larger cylinder and subtract the smaller from the union. 8. In the Right view construct a cylinder of radius 10 and height 70 for the holes in the fork. 9. In the Front view move the cylinder to its correct position in the fork and subtract from the fork. 10 In the ViewCube/Isometric view fillet the bottom corners of the fork ends to a radius of Make the Cyan layer current. 12. In the Right view construct a cylinder for the pin of Radius 10 and height In the Front view move the cylinder into its correct position central to the fork. 14. In the Top view add suitable lighting. 15. In the ViewCube/Isometric view attach materials to the fork and pin and render the model. 16. Call the 3D Orbit tool and move the model to a new pictorial position. 17. Save the model drawing with the file name 17_Exercise06.dwg to a memory stick. 18. Close the drawing window.

8 Page 8 Chapter 17 Exercise 7 1. Open AutoCAD 2012 with a double-click on its shortcut icon in the Windows desktop. 3. Set UCSFOLLOW to In the Front view construct an outline of the body of the steady and extrude to a height of In a Right view set a UCS 3point on the front face of the extrusion. 6. At the holes construct plines for solids of revolution for the bosses to the holes. It is easiest to construct one of the bosses, then go into the Front view and copy the single boss to the other holes. Then form a union of the body and the bosses. 7. Set a UCS 3point along the line of the sloping top edge of the body. This will allow the construction of the holes for the part 2. Subtract the cylinders from the body. 8. In a similar manner construct the holes for part 2 at the right-hand side of the body - form a UCS 3point along the right-hand edge. While in this UCS make the Red layer current and construct the two parts of part Go back to Front view, copy the two parts of part 2 and rotate the copy to fit into the upper two holes. 10. Make Magenta current and set a Right view. Construct both a part 4 and a part Move the parts just constructed to their correct positions. Note If desired more realism can be given to the screw threads by constructing the plines for the required screws and bolts as follows: (a) For part 4, for example, construct this polyline outline. The command line sequence for the thread would be: Command: enter pl right-click Specify start point: pick Current line-width is 0 Specify next point or [Arc/Close/Halfwidth/Length/Undo/Width]: right click Specify next point or [Arc/Close/Halfwidth/Length/Undo/Width]: right click

9 Page 9 Specify next point or [Arc/Close/Halfwidth/Length/Undo/ Width]: right- click Specify next point or [Arc/Close/Halfwidth/Length/Undo/ Width]: right- click and so on until the required length of thread is completed. (b) Then call REVOLVE. The result will be as shown. (c) The screwed holes for the screws and bolts could be constructed in a similar manner. 12. Add suitable lighting and materials and render the completed model. 13. Save the model drawing with the file name 17_Exercise07.dwg in a memory stick. 14. Close the drawing window.

10 Page 10 Exercise 8 1. Open AutoCAD 2012 with a double-click on its shortcut icon in the Windows desktop. 3. Construct plines as shown - working to your own dimensions. 4. Place the drawing in the Front view, Zoom to 1 and copy the plines vertically upwards by a suitable number of units. 5. Place in the Southwest Isometric view. 6. Set SURFTAB1 to 36 and SURFTAB2 to Enter rulesurf at the command line. The command line shows: Command: _rulesurf Current wire frame density: SURFTAB1=36 Select first defining curve: pick the top line at the front Select second defining curve: pick the bottom line at the front. Command: 8. Continue forming the ruled surfaces on the other three sides and the base. 9. Make the layer Construction current. 10. In the Front view make a new 3point UCS above the top of the model. 11. Construct pline arcs at the left and right-hand ends the same as those in the model and plines from the ends of the arcs. 12. Turn layer 0 off. 13. Form a 3point UCS across the ends of the smaller arc and construct a pline arc between the ends of the smaller arc. 14. Go back to the Front view and form an arc in a similar manner across the ends of the larger arc. 15. Form edgesurfs across each of the three surfaces. 16. Open layer 0 and make it the current layer. 17. Call Hide

11 Page Place in the Top view and add lighting. 19. Attach materials and render. 20. Save with the file name 18_Exercise01.dwg to a memory stick. 21. Close the drawing window. Exercise 9 1. Open AutoCAD 2012 with a double-click on its shortcut icon in the Windows desktop. 3. In the Front view construct the polyline as shown in Fig.????. 4. In the Top view copy and rotate and move the pline until there are four plines as required for the edgesurf surface. 5. Place the drawing in the Southwest Isometric view. 6. Set both SURFTAB1 and SURFTAB2 to Enter edgesurf at the command line. Following the prompts at the command line pick each of the four plines in turn

12 Page Left-click in the surface and left-click on Green in the popup list from the Home/Properties panel. The surface changes colour. 9. Select the Realistic visual style. 10. The surface changes to a green Realistic shaded surface. 11. Save the model drawing to a file name 19_Exercise01.dwg in a memory stick. Exercise Open AutoCAD 2012 with a double-click on its shortcut icon in the Windows desktop. 3. In the Front view and working to dimensions of your own choice construct the plines for the three edgesurf surfaces. The curved plines Object 1 and Object 2 are best constructed on two 3point UCSs. 4. Set both SURFTAB1 and SURFTAB2 to 24.

13 5. Enter edgesurf at the command line and form the surfaces by picking each of the four edges for each of the three surfaces in turn. 6. Change the colour of the three surfaces to red. 7. Erase the original plines on which the edgesurf surfaces had been constructed. 8. Set to the Shaded visual style. 9. In the Top view add suitable lighting. Page In the Southwest Isometric view attach a material and render. 11. Save the drawing to the file name 19_Exercise05.dwg in a memory stick. 12. Close the drawing window. 12. Close the drawing window. Exercise Open AutoCAD 2012 with a double-click on its shortcut icon in the Windows desktop. 3. Make a new layer magenta of colour magenta. 4. In the Top view construct a semicircle of radius In the Front view construct a semicircle of radius 75. Move the semicircle so that its left-hand end is central to the radius 25 circle. 6. Place in the Southeast Isometric view. 7. Call the Extrude tool from the Home panel. 8. Extrude the radius 25 semicircle along the path of the radius 75 semicircle. 9. Save the model drawing with the file name 17_Exercise08.dwg in a memory stick. 10. Close the drawing window.

14 Page 14 Additional exercises 1. A rendering of a 3D solid model drawing of a small platform which can rotate in its forked holder is shown. Construct a 3D solid model drawing of the platform and its holder working to the details given in the two-view third angle orthographic projection below. Add suitable lighting and materials and render the model. 2. A 3D solid model drawing of a garage is shown to the right and details of its sizes are given in a two-view drawing on below. The thickness of all parts except the roof is 2.5, the roof thickness being 2. The hatching of the roof and front wall needs to be placed on a flat plane which is then placed over the extrusions forming the roof and wall. Construct the 3D solid model drawing.

15 Page A two-view drawing of a link is shown below. Working to the details given in this drawing construct a 3D solid model drawing of the link, followed by adding lights and a suitable material before rendering. 4. A rendered tumbler is shown below. Working to the details given in the polyline outline, construct the outline and from it produce a solid of revolution. From the resulting 3D model subtract elliptical finger grip cutouts, before rendering, add suitable lighting and a glass material. Published by Elsevier Ltd. All rights reserved

16 Page 16 Multiple choice questions 1. The term UCS stands for: (a) User Coordinate State (b) Using Coordinates Screen (c) User Coordinate System (d) User Coordinate Set 2. Before the UCS system can be used: (a) The set variable UCSFOLLOW must be set to 1 (b) The set variable UCSFOLLOW must be set to 0 (c) It does not matter whether the set variable UCSFOLLOW is set to any number, the UCS system will still operate (d) The set variable UCSFOLLOW does not need to be set because it becomes operative when the UCS is in use 3. Before the UCS system can be used, the UCS icon: (a) Must be showing somewhere on screen (b) Need not appear anywhere on screen (c) Must be showing at the bottom left-hand corner of the screen (d) The UCS icon can only show on screen if the setting of the set variable UCSFOLLOW is correct 4. The term UCS WORLD applies to: (a) The plane on which the operator is working at the time (b) The standard XY plane which appears when AutoCAD is loaded on screen (c) Any one of the orthogonal planes (d) Any plane set when working in the UCS 5. A 2D outline constructed using the line and circle tools can be extruded to form a 3D model: (a) Yes (b) No (c) Only if it is first made into a region (d) Either if it is first made into a region or if its outline is edited to form a closed polyline