Now that the gaming / racing wheel has been made, let's build the steering's base. Take a card board box of approx 30cm x 20cm. Make sure that the box is firm enough. I used a logitech joystick's packing box for construction. Take a bolt of sufficient length and fix it on to the steering through the hole that you have drilled. Fasten the bolt using it's nut. You can cover the nut with hard adhesive to provide better support on the plywood. Now take two metal pipes (aluminium preferably). The larger pipe should have around 3cm diameter and the smaller one having 1cm diameter. The larger metal pipe should have a length not less than 20cm and the smaller pipe should have a length not less than 30cm.

Make a hole at the center of the box and pass the larger pipe through it so that only 1/3rd of it remains outside. Place the pipe slanting slightly upwards. Fix the pipe on to the box using the hard adhesive (MSeal). Use superglue if needed to provide extra strength to the gaming / racing wheel. Cover the outer end of the large pipe using the hard adhesive and make a hole through it large enough to pass the smaller metal pipe through it. Perform the same on the other end. Now insert the bolt into the smaller metal pipe and bind it using adhesive. Make sure that the alignments are always parallel. When the adhesives cures, you can pass the smaller metal pipe through the larger one attached to the box. Now you should be able to rotate the wheel freely on its base. If the rotation is not smooth, you can put more adhesive and file it up near the contact points where the larger pipe meets the smaller one.