3D solid modeling starts with extrude. Like other 3D software, these commands work similarly with AutoCAD 2009 as well. Only difference is in order to rotate working plane, you have to rotate the UCS itself in such a way that “XY" plane become aligned with working plane. We don’t have 3D cut options directly available with AutoCAD 2009, however we can use subtract command for that. Let’s now discuss extrude and revolve commands one by one.
When you can think of extrude to be used?
Extrude is the basic material addition process. So the starting feature of your model could be extrude. Normally, non axisymmetric geometry is modeled using extrude. Cube, bricks and combinations of cube and bricks are some shapes for which you can use extrude.
How to do 3D modeling using extrude?
Set the workspaces to 3D modeling by following menu browser> tools>workspaces> 3D modeling.
Now go to the home ribbon tab, here in 3D modeling panel you will see the extrude icon but before clicking the icon your sketch, which you want to extrude, should be ready. The sketch can be line, polygon, triangle, rectangle etc. If you use line as a sketch and try to extrude it, it will become surface. Click on the extrude button now, it will ask for the objects to extrude, select the sketch or even you can select any existing surface as well. Give the height, how much it should be extruded, and you are done with extrusion.
We will take an example of creating cylinder of 200 mm diameter and 1000 mm height. You have to draw a circle of 200 mm diameter. Go to home ribbon tab of your 3D workspace and click on the extrude icon of 3D modeling panel. Select the circle and specify height as 1000.Your cylinder is ready.
How to create extrude feature on a plane other than preset XY plane?
As of now you can create any extruded feature on working plane (XY). But if the geometry is like below:
Then, how will you proceed? Please observe in the picture, there are two extruded features and the second feature, the cylinder is constructed on one of the surface of the first feature. For these kinds of geometry you need to change the working plane.
For creating the parallelepiped you need to draw a square and need to extrude it. Now go to the view cube, below it there is something written as wcs, click on the small triangle adjacent to it and click on the new UCS, you are in process of creating a new UCS, click on the bottom left corner of the surface (point A in the figure), it will ask for X axis direction click on point B and finally to define XY plane click on point C.
You will observe, the position of UCE has changed; now draw a circle on this surface and extrude it to get the final geometry.
Extrude is the most commonly used feature in 3D modeling. Close and open sketch could be extruded. To get the extrude icon, you should change your workspace to 3D modeling. To draw sketch on a plane other than current XY plane you need to change the UCS accordingly.