FOLLOWING ALONG THE PATH

Transcription

1 FOLLOWING ALONG THE PATH 3D MODULE 18 OBJECTIVES At the completion of the Module you should be able to: Create a solid model by extruding a profile along a predefined pathway. Use the Press/Pull command to create an extruded object. **************************************************************************************************************** EXAMPLE 8 TOILET ROLL HOLDER Start a New drawing and Use a Template 3D2STAN.dwt and Save As XX3D18_PRIM01. Leave the drawing limits as set. Start work in Model Space with the WCS current. The solid model drawing objective is to construct a Toilet Roll Holder, as shown below. As usual, there is a choice of solid model construction methods that we could use: primitives, solid composite commands, etc. The most efficient construction method for this model would be to use the Extrude command, either by stating a thickness or tracking around a predefined path. Before starting the drawing take time to sketch out a storyboard. AutoCAD 3D Design Tutor (R2013) Page 18: 1

2 Sequence of Production 1 Draw construction lines. 11 Union Base and Spigot. 2 Produce polyline. 12 Add Spigot centre lines. 3 Fillet polyline. 13 Draw polyline path. 4 Draw profile and convert to Region. 14 Draw 15mm Circle at end of path. 5 Extrude profile along polyline path. 15 Extrude Circle along path. 6 Extrude polyline 15mm. 16 Subtract 15mm hole from Spigot. 7 Union inner and outer. 17 Dome profile converted to Region. 8 Copy centre lines and offset. 18 Revolve Dome profile. 9 Draw polyline. 19 Mirror Dome and Fillet Spigot end. 10 Extrude polyline and fillet. 20 Union Dome and Handle and add Securing holes. Story 1 Make Layer CONSTRUCTION current. View from the SW Isometric. Set out the construction lines as below. Page 18: 2 AutoCAD 3D Design Tutor (R2013)

3 Story 2 Transfer the centre lines to the Layer CENTER. Make Layer SOLID1 current. Install the Rectangle command and pick at P1 to P2 using (Osnap INTersection) at each corner to draw a closed rectangle. Freeze Layer CONSTRUCTION. Story 3 Apply a 20mm fillet radius to each corner, using the 'Polyline' option in the Fillet command. Story 4 Make Layer SOLID2 current. Move the UCS, Origin to P3, followed by UCS, Xaxis Rotate to an angle of 90 and Yaxis Rotate to an angle of 90. Draw the profile shown below and convert into a Region (one object). AutoCAD 3D Design Tutor (R2013) Page 18: 3

4 Save the drawing and Save As XX3D18_PRIM02. Story 5 The intention is to extrude this profile around the rectangular path. Reset the UCS to WCS. Install the Extrude command. Home Modeling Extrude OR Modeling TB Typed command: EXTRUDE _extrude Current wire frame density: ISOLINES=10 Select objects to extrude: Pick the profile just drawn. Type: Select objects to extrude: 1 found Select objects to extrude: Specify height of extrusion or [Direction/Path/Taper angle] : Type: P (Path) Select extrusion path or [Taper angle]: Select by picking the polyline rectangle. The profile is now extruded around the path. Page 18: 4 AutoCAD 3D Design Tutor (R2013)

5 Note: If AutoCAD responds with the error message: Profile and path are tangential. Unable to extrude the selected object. The Region or polyline profile to be extruded must be rotated 90 and relocated before the Extrude will work. As we said before, there are many ways to achieve the same result, and depending on your procedure for creating the closed polyline path, as to what outcome you will achieve. Story 6 Although the outer edge has been completed the centre is still hollow. Again we will use the Extrude command. Set Layer SOLID1 current. Freeze Layer SOLID2 (removing the outside edge just created), which should again expose the filleted polyline rectangle on Layer SOLID1. Copy the filleted polyline and change the copied polyline to Layer FRAMES to retain a copy. Freeze the FRAMES Layer. Install the Extrude command. Pick the filleted rectangle when the Select objects to extrude:. Specify height of extrusion or [Direction/Path/Taper angle] : Type: 15 The rectangle is now displayed extruded. AutoCAD 3D Design Tutor (R2013) Page 18: 5

6 Save the drawing and Save As XX3D18_PRIM03. Story 7 Thaw Layer SOLID2. We will use the Union command to merge the outer edge profile to the inner extrusion. Ensure the inner extrusion is selected first when unifying so that Layer SOLID1 will be the dominant feature. To achieve this easily:- Install the Union command. _union Select objects: Hold the <Shift> key down and move the cusor over an edge between the two solid objects. Pick the SPACEBAR on the keyboard while continuing to hold down on the <Shift> key to toggle between the two solid objects. Pick the SPACEBAR until the inner extrusion is highlighted and then release the <Shift> key and pick to select the inner extrusion. Select objects: 1 found Select objects: Pick the outer extrusion. Select objects: 1 found, 2 total Select objects: Type: (to complete the Union) Note: The Shift+SPACEBAR Select objects: option may be used whenever two or more objects need to be toggled for selection, e.g. lines on top of lines, etc. Try it on your own. Install the Visual Styles, Realistic option to view the completed box. Return to the UCS 3D Icon by selecting the 2D Wireframe command. Page 18: 6 AutoCAD 3D Design Tutor (R2013)

7 Story 8 The next task is to draw the spigot on the front face of the box just created, which will retain the Roll Holder. Copy the centre lines up the Z axis by 15mm. Move the UCS Origin to the top intersection centre lines. Offset the X axis centre line by 52mm. Offset about the 52mm offset centre line and the Y-axis to the distances shown. This now displays four corners in which can be drawn a polyline line, which can then be extruded. Story 9 Set Layer SOLID2 current. Install the 2D Polyline command and overdraw, starting at P4, each intersecting corner of the offsets just completed and close. AutoCAD 3D Design Tutor (R2013) Page 18: 7

8 Temporarily freeze, Layer CENTRE, leaving the rectangle clearly visible. Save the drawing and Save As XX3D18_PRIM04. Story 10 Reinstall the Extrude command and specify a height of 43mm. The spigot is now displayed in position. A semi-circle is to be added to the top of the spigot. Install the Fillet command and when the, Select first object or [Undo/Polyline/Radius/Trim/Multiple]: Pick edge P5. Type: Enter fillet radius: 15 Select an edge or [Chain/Radius]: Pick edge P6. Type: Select an edge or [Chain/Radius]: The two edges are now filleted. Save the current drawing and Save As XX3D18_ PRIM05. Story 11 Use the Union command to unify the base and spigot. Page 18: 8 AutoCAD 3D Design Tutor (R2013)

9 Story 12 Thaw Layer CENTRE and make it current. Draw centre lines on the spigot ready for the handles path to be inserted. Reposition the UCS, Origin onto the rear face centre lines of the spigot at the centre of the arc. Use the Named UCS command to name the current UCS position called RFACE. Story 13 Set Layer SOLID2 current. Draw the path to the dimensions shown. Note: Use the Top Viewpoint to draw the path. This is often easier than an Isometric Viewpoint. Return to SW Isometric Viewpoint when finished. Convert the path into a polyline using the Polyedit (Pedit) command. AutoCAD 3D Design Tutor (R2013) Page 18: 9

10 Story 14 Use the UCS, X Axis Rotate to rotate the UCS 90. Repeat the same procedure but this time use the UCS, Y Axis Rotate to rotate -90. Draw a Circle of 15mm diameter. Save the current drawing and Save As XX3D18_ PRIM06. Step 15 Install the Extrude command once again and select the circle as the object to extrude and the handle centre line just drawn as the path. Pick the Path and change its Layer to FRAMES (Frozen Layer). Use the Visual Style, Realistic option to view the resulting handle. Story 16 Return to the 3D UCS Icon by using the 2D Wireframe command 15mm diameter hole in the Spigot. and we will next create a Make Layer SOLID3 current. Page 18: 10 AutoCAD 3D Design Tutor (R2013)

11 Freeze Layers SOLID2 (handle) and CENTRE. Change the Viewpoint to NE Isometric to view the rear side of the handle with the UCS, Origin as above. Create a 15mm diameter Circle at 0,0,0. We will us the Press/Pull command to create a hole through the Spigot. You can press or pull bounded areas by using the Press/Pull command. The area must be bounded by coplanar lines or edges. Home Modeling Press/Pull OR Modeling TB Typed command: PRESSPULL _presspull Click inside bounded areas to press or pull. Pick inside the 15mm diameter circle (not on the circle itself) just created to highlight it. The cylinder is attached to the cursor. Drag the cylinder and using Osnap CENtre pick the centre of the arc on the backside of the Spigot or use direct entry method by typing 16 (depth of the Spigot). 1 loop extracted. 1 Region created. The cylinder is automatically subtracted from the Spigot. Use Visual Style, Realistic to see the results. Refer to AutoCAD Help for additional information on the Press/Pull command. Try using the Press/Pull command on other bounded areas at your leisure. Save the current drawing and Save As XX3D18_ PRIM07. Story 17 It now leaves just the domed ends to be added to the spigot. Return the UCS to the RFACE saved UCS using the Named UCS command. Thaw and make Layer SOLID2 current. Draw the following profile from the UCS origin and make into a Region. AutoCAD 3D Design Tutor (R2013) Page 18: 11

12 Save the current drawing and Save As XX3D18_ PRIM08. Story 18 Install the Revolve command and revolve (360 ) the profile around the X axis to create the dome. Story 19 Finally use the 2D Mirror command to create an inner dome on the other side of the spigot. It should look like this. Apply a Fillet radius of 5mm to the end of the handle. Page 18: 12 AutoCAD 3D Design Tutor (R2013)

13 Save the current drawing and Save As XX3D18_ PRIM09. Story 20 Unify the inner and outer dome to the handle using the Union command. It leaves just two securing holes. Return the UCS to the World. Offset the centre line 70mm either side of centre. On Layer SOLID3, at the midpoint of the centre lines, create two Cylinders with 8mm diameters, Height of -20. Save the current drawing and Save As XX3D18_ COMP. Subtract the Cylinders from the base. Chamfer the edge of each hole with Distances of 2. Change the Viewpoint as necessary to achieve the results. Save the completed drawing. Note: This Module was intended to give you a wide variety of options for using the Extrude command. More efficient methods could have been used. For your own practice, explore how you could shorten the Storyboard by simplifying/combining drawing and Boolean operations. AutoCAD 3D Design Tutor (R2013) Page 18: 13

14 TASKS Construct this spring bracket as a solid model using initially the Extrude command, Profile/Path option. The path route is dimensioned on the right. The bent tag could also be drawn by the same method. It should result in the following. Save As XX3D18TASK. Page 18: 14 AutoCAD 3D Design Tutor (R2013)