Create a Revolution

This lets you create a positive or negative volume by rotating a user-defined loop (a 2D profile) through a specified angle around a given axis. The Axes controls let you define the axis about which the loop will be rotated, and the plane in which the loop is defined (the start of the generated shape).

Note: When you display the form, you will automatically be in event-driven graphics mode ready to pick a line defining the axis.

1. From the main menu bar select Utilities > Constructs, the 3D Aid Constructs form appears, now select Create > Line > Explicit.

   

   The Modify Line form appears, and also in the graphical view a line is shown.

2. Select the position of the line and the length.

   This is the start position which we will use as the rotational axis.

3. Click OK to confirm the lines position and length.

   

4. Now using the Design Explorer navigate to the equipment element and select Create > Primitives from the main drop-down menu.

   The Primitives form appears.

5. Select the primitive required from the available menu.

   For example, Solid of Revolution.

   

   The +ve Revolution form appears.

6. In the Settings area, enter the Angle through which the loop is to be rotated.

   You can either type the angle in explicitly, or use the right button mouse menu to derive the angle by picking existing design items.

7. From the Axes section select Rotation Line.

   In the prompt area of the screen a message tells you to Pick line to rotate about.

8. Select the line previously created and this will be our axis.

   

9. Now on the +ve Revolution form the Point on Plane option is active, select the Point to Plane option.

10. Choose from the positioning control Explicit Position.

    

    The Ship Position window is displayed.

    

    Note: The Ship Position window (Format Grid) allows a position to be entered using ship frame and longitudinal references or as an absolute position in the world coordinates.

11. Right click over Format and select Format XYZ and enter in X = 100, Y = 0, Z = 0.

    This is the plane in which the loop is defined (the start of the generated shape).

12. Click Apply.

    The Create section on the +ve Revolution window is now displayed.

13. Select Pick points.

    In the graphical view it now shows the rotational line and the start position for the shape.

    

    The Positioning Control form is displayed.

14. Once again, select Explicit Position.

    

    The Ship Position window is now displayed.

15. Key in the values for the position of each Vertex, clicking Apply for each new position.

    

16. Once all the Vertex positions have been entered, click OK on the +ve Revolution form.

    The Revolution primitive is created.

    

    The Revolution Vertices have an attribute Fradius, if we change this for the vertex 3 and 4 then this will modify the extrusion as shown