Basic 3D Commands in AutoCAD 2009: Revolve

If you are using AutoCAD 2009 or any other 3D software, you may have noticed that some of the geometry could be created using both extrude as well as revolve. For example, a stepped shaft (means a shaft with different diameters at different sections) could be modeled using both the command. But it is always recommended that you use revolve instead of extrude in such cases because revolve takes much lesser time. In revolve, the whole shaft could be created in a single command however for creating the same using extrude you may be required to use more than two commands.

The objects like cylinder, pulley, ball etc are said to be axisymmetric. These objects will have an axis and by rotating a section around this axis could generate the object itself. Take the example of the cylinder, if you create a rectangular section and revolve it around

a axis, you will get the cylinder. In other words, axisymmetric objects are created by arranging infinite number of slices around the axis and all the slices are identical.

For all axisymmetric model you can use revolve command. Some time you may come across with the objects which are not fully axisymmetric. Like, you have to model the wheel of a bull cart, for doing this you may have to go for additional cut operations after using revolve. In pro engineer and other 3D software, you have a command called pattern, which is used quite extensively with revolve to get the final model quickly.

Whether to use revolve for a model or not that depends entirely upon the geometry and the software you use. On an average for AutoCAD 2009 you can start all axisymmetric models with revolve.

As you know that in AutoCAD you cannot sketch sections in any 3D commands, so get your section ready before hitting the revolve command. Change the work space to 3D modeling by:

Menu browser> tools> work spaces> 3D modeling

You can see the 3D modeling panel in your home ribbon tab. Go and hit the revolve icon, it will ask for section to revolve, select the section you have already sketched. It will ask you to define axis of revolution, you need to select two points for that. Specify the revolve angle, most of the cases it should be 360 degree. After all this you will get your revolve feature ready.

The section, which you have sketched, could be open as well as close for AutoCAD 2009. If you choose open section, you will get surface as revolved object or else it will be solid.

Revolve is a handy command for axisymmetric objects. If you have a model which could be done by using extrude as well as revolve then it is recommended that you opt for revolve. In AutoCAD 2009 section for revolve could be either open or close. If it is an open section you will get revolved surface or else it will be solid.