This is a very basic tutorial I have devised for building an alloy wheel. It's no pro stuff, but it might help you get your head around some of the shapes if you're very new to CAD. I'm sure there are more impressive methods and tons of features I've not discovered yet so I'll post any developments I make - it gets the job done quick and easy though.
1. Measure out lines for half the height of your wheel in side view and draw a profile for the inner surface of the rim.
2. Complete the profile for the outside surface of the rim. Leave the bottom draft-line as a centre point for the rim.
3. Lathe the rim around the centre line.
4. Do the same for the side profile of your wheel spokes and hub and lathe it into a solid disc.
5. Switch to front view, create a circle the same diameter as the disc and draw into it the profile for one of your spokes.
6. Use Mirror and Rotate to copy the spokes equally around the circle, or alternatively use Copy Along Path to array the spokes between the circle and centre-point to the desired number.
7. Create an inverse pattern of the spoke design so it represents the gaps between them. Add a circle in the centre to make a hole for the hub-axle and around it, 5 equally spaced holes for the wheel-studs.
8. Align the new profile to the centre of the wheel and use it to cut out the disc. The basic wheel shape is finished!
For a finishing touch, put a hole through the front rim for a tyre-valve at roughly a 60 degree angle.
Adding a Tyre:
Again, this is just an ultra basic tyre and I've only drawn mine to a rough scale just to look the part.
Rendered with some decals it doesn't look too bad I must say for an afternoon's work.
