Isometric drawings in Autocad have largely been superseded by the 3d functionality of the program, which has been around for the best part of ten years now. However, it’s still sometimes necessary to draw a simple isometric drawing for a machine part to give a client an idea of how the object looks in three dimensions. Isometric drawings are also used for piping diagrams. This is one of the many features we cover in our Autocad courses.
It’s a good idea to snap to an isometric grid to help with the drawing, as follows. Right-click on the Snap icon on the bottom Status bar and choose Settings. Then select Isometric Grid and make the Snap and Grid spacing 10mm, for example. Also tick Display Grid Beyond Limits. Turn on Grid (keyboard shortcut F7) and Snap (F9) and hit OK. If the Grid is not wholly visible, zoom in and click once with the mouse-wheel. In older versions of Autocad you have dots instead of lines.
Select the Line tool and start with an upright line 50 mm in length, as in the left-hand diagram – note that the Line tool wants to snap to the grid lines. Draw each of the lines 50 mm long to make up the cube – if you have Dynamic Input selected on the Status bar you’ll have a better idea of line lengths.
To draw the ellipses, we need to establish the midpoints on the cube’s surfaces. Create a red Construction line layer and draw two diagonal lines from the adjacent corners. then return to your drawing layer and go to the Ellipse tool drop-down arrow > choose Axis-End. Then type I in the Command window for Isocircle, and drag out an ellipse somewhere to the side, radius 15. If the ellipse does not conform to the correct  isoplane press F5 to switch planes, then add the radius 15. Then use the Move, Copy, Rotate and Mirror functions as normal.
When the isometric part of the drawing is complete, return to normal view snapping by typing Snap in the Command line, then S for Style and  S for Standard.
More information on all features of Autocad can be found at the AutoDesk website. And see many examples of our clients’ work on our Facebook page.
Other related Autocad 2d Blog Posts:

• Autocad 2d basics
• Autocad 2d introduction
• Autocad 2d drawing
• Autocad 2d workspace