Step 1: Download Autodesk 123D
Step 2: Design the Wheels
Starting with one wheel, sketch circles (Sketch > Circle) to represent the outer boundary of the tire, the hub, and what will likely be a metal frame between the two.
After that, use the extrude tool (Construct > Extrude) to give the wheel the desired thickness, extruding the “hub” and the “metal frame” to slightly shorter levels than the tire itself. On the other side of the wheel, project the surface, and create the same extrusions on the hub and the frame as the first side.
Using the Modify fillet tool, round off the top surfaces, and then add color to the hub, frame, and tire using Materials. What started as a few circles should now be looking much more like a wheel.
Once you have finished the first wheel, use the Rectangular Pattern Tool (Pattern > Rectangular Pattern) to create a second wheel, and punch a hole in the center of each wheel.
Be sure to SAVE your file.
For a step-by-step video tutorial on this stage, see this video: