3D Modeling Types

Wireframe Modelling - Wireframe modeling is useful for initial design iterations and as reference geometry, a 3D framework for subsequent modeling or modification.

Surface Modelling - Surface modeling offers fine control over curved surfaces for precise manipulation and analysis.

Solid Modelling - Solid modeling is efficient to use, easy to combine primitives and extruded profiles, and offers mass properties and sectioning capabilities.

Procedure

1. Open your Inch Titleblock and SaveAs “Column”

2. Draw the 2 bottom holes of the cylinder

Note: The WCS icon seen in this diagram is different than yours as the image is from an older AutoCad version. Newer versions use a 3D WCS icon by default.

WCS = World Coordinate System

3. Select the front right corner of the navigation View Cube to get a 3D isometric type view.

4. Copy the bottom part of the cylinder up the correct amount.

Use Relative Coordinate Entry @x,y,z

• x = 0
• y = 0
• z = height of cylinder

5. Draw a line from the quadrant of bottom circle at A to the quadrant of top circle at B

6.     Draw a line from the center of the bottom circle the distance needed to the center of the horizontal circle. This will be 3.5

7. Move this line up to the height of the center of the circle which is halfway up the height of the cylinder (use Midpoint OSnap).

• Notice the location of the WCS (World Coordinate System) icon
• To be able to draw on the plane of these vertical and horizontal lines we need to move the icon to a new location in the next step.

8. When you move the icon it is no longer the World it becomes User. UCS (User Coordinate System)

• Type UCS
• Snap the icon to point A
• Snap to point B to set the X axis
• Snap to point C to set the Y axis
• Notice the view cube has changed and is no longer WCS

9. This will be a UCS you will want to get to again therefore you should save it:

• Type UCS
• Type NAme (just NA)
• Type Save (just S)
• Name this UCS view as FRONT

10. Now you will be able to draw the 2 circles on the new UCS xy plane

• Working with 3D objects requires a good ability to move the UCS to where you need it.

11. Copy the line in the center to the top and bottom quadrant of the circle.

• Note: Your view will look somewhat different as this view is slightly turned.
• The lines look like they are connecting with the top and bottom of the cylinder circles in this view.
• You can spin your 3D drawing by Left clicking on the View Cube and then moving around. You should try this out.

12. To turn the view so the new UCS is straight on:

• Type PLAN.
• Right Click (or hit Enter) to select the Current UCS view.

13. Select TRIM

• Select the top and bottom line as cutting lines.
• Select the circle to trim.

Note: the picture looks like the horizontal part has move upward but if you use the View Cube and spin around you will see that it has moved backwards, not up.

14. Left click and hold on the View Cube and tilt around to approximately the 3D view you had before

15. Move the horizontal part backwards in the Z axis

• Use a relative command
• x,y,z
• x = 0
• y = 0
• z = a negative amount

16. Copy the horizontal part forwards in the Z axis

• Use a relative command
• x,y,z
• x = 0
• y = 0
• z = a positive amount
•

17. You now need to change the UCS back to the World view WCS.

• Select “Unnamed” under the View Cube and select WCS.

18. Select the TOP on the View Cube

• If you cannot see the TOP on the View Cube tilt it around.

19. If needed, use the arrows to get the TOP view rotated correctly.

20. Trim the edges by selecting the cylinder circle as the Cutting Edge then the Lines to trim.

21. Use the View Cube to get back to a 3D isometric view then delete the lines A & B

22. Copy the top and bottom circles of the cylinder down and up to match the trimmed lines

• Use Relative Coordinate Entry

23. Select the horizontal lines to be cutting edges and trim the circles A & B as shown in the next step.

24. Create a line from A to B

25. Then copy the line from B to C.

26. Change to the FRONT UCS

• UCS
• R
• FRONT

27. Draw line A to B

28. Draw line A to B

29. For the Surfacing portion of the assignment you will need to have the circle split into 2 arcs

• With Trim select both Line Aand the small Circle B as the cutting edges.
• Then select the center portion of line A and the B side of the circle to trim them.

30. Select the half circle and Mirror it over to become 2 arcs that make up the circle (this will be needed for the Surfacing)

31. Under the Modify toolbar select Polyline Edit

• Select the dashed Line near A
• Select Y (right-click) to turn this line into a polyline
• Select J for Join.
• Select the dashed Arc and the dashed Line near B
• Right click when finished selecting then right click again to finish the command.

When finished Editing the Polyline you should see a dashed line as above if you select anywhere on the polyline.

If the whole line is not dashed then there is something wrong with your polyline and it will need fixing.

32. Copy the front side line A to the backside B

33. The wireframe model is complete and is now ready to be surfaced in the next section.

Surface Procedure

1. Before surfacing the wireframe model you will need to setup the following:

• Create a new Layer called MESH and make it Magenta in color
• Type SURFTAB1 and set it to 15
• Type SURFTAB2 and set it to 15
• NOTE: Surftabs set the number of lines that will make up the mesh. It depends on the object what these settings should be – trial and error.

2. Starting with the Cylinder you will need to use RULESURF for the curved wireframe.

• RULESURF
• Select circle A then B
• Repeat the above for the inner circles.
• NOTE: For a smoother mesh you would need to increase the Surftab settings.

3. To make it easier to work with the wireframe and mesh it is best to move the mesh to one side the same amount each time (so they line up).

• MOVE
• Select Cylinder Meshes
• Select a base point
• Move the meshes 10 (or 20) in the Y-axis

4. Using RULESURF you will add the curved mesh caps

• RULESURF
• Select top Cylinder Circles A & B
• Repeat for bottom Circles.
• Repeat for front Arcs C&D
• Repeat for back Arcs.

5. Move these new meshes to same amount you moved the first set.

6. Using RULESURF you will add the curved end.

• RULESURF
• Select Arcs A & B

7. Move this mesh

8. You will use TABSURF for this next mesh. Tabsurf needs the Path Curve (a 2D object – in this case the small circle), plus the Direction Vector (a line)

• TABSURF
• Select the Path Curve – the small circle at the back (as it is a full circle, unlike the front which is 2 arcs.
• Select the Direction Vector line.

9. Move this mesh.

NOTE: The polyline D you created earlier was necessary as Edgesurf can only be created between 4 lines.

10. For this next step you will use EDGESURF to fill the 4 lines with a mesh.

• First change the Surftabsettings
• SURFTAB1 – set to 6
• SURFTAB2 – set to 10

11. Create the Mesh

• EDGESURF
• Select line A, B, C and D

12. Copy the new mesh from A to B

13. Move this mesh.

14. Use EDGESURF to create the mesh.

15. Copy this mesh down.

16. Move this mesh.

17. If you use the HIDE command you will view this as shown, but if you were to print this the hidden lines would still be there.

• Go to print and select Print Preview to see that the hidden lines are back. You will fix this display setting later on.

18. Go to Paper Space or Layout view with your Title block:

• Changed the viewport so it only fills half the titleblock – grab the grips and move them to fill half.
• Copy this Viewport to the other half of the title block.
• Use the ViewCube to get 2 views of the Column, as shown.

19. To get this to print as hidden you will need to change the display:

• Select the Viewport box
• Select the Properties arrow to open the Properties dialogue box.
• Under Shade Plot select the As Displayed arrow and pick LEGACY HIDDEN
• NOTE: Try some of the other options to see what they do, but depending on the settings – object colour or materials it may not look very good.

20. Save, Print and Handin