The wheelz are cut out of 1" thick pink insulation board, you can also substitute styro-foam packing material. I did.
Use a 2" diam. hole saw bit for your drill to cut out your wheelz.
You might want to do this outside as you will make one heck of a mess if you work with the white styro-foam.
You could also uze a foam cutter or even a saw to cut out your wheelz.
Once you have your rough cuts you can smooth your wheelz out a little with s sanding block or a piece of sandpaper laid flat on your work surface.
This doesn't have to be perfect because you will be covering all the exposed foam with card just like the hull.
Next you need to drill out holes for your axels to fit through.
I put the holes close to the corners of the hull, about 1/4" away from the edges of the hull.
If Using a drill to make the holes, you might hit a few of your nails while drilling.
If so you can pull them out and refit them later, or just cut them down to fit.
Wire cutters or nippers work pretty well cutting down the nails.
Drill a hole into the center of each of your wheelz.
This does not have to go all the way through, but you can.
I stopped at the out side layer of card.
Trial fit your wheelz to your axels.
I have 2 wooden dowel rods each about 8 " long.
cut to the proper length and your ready to rumble.
The axels will not be glued together until the painting is finished.
Trace out 2" circles on your thin card board using your wheelz as a template, make two for each wheel.
Just like on the hull, glue these cut offs to the sides of your wheelz with white PVA glue (Elmers glue).
Pin the plates down with 4 or more nails along the edge to hold the card in place.
You can remove these later if you like but I left mine in for affect.
Once dry you can work on da treds.
Cut out about 8 strips of thin card 1 1/8" wide by about 9" long.
Put four aside to be used as your wheelz tred base, the other 4 you will cut into 1/2" plates.
Take your 4 uncut treds one at a time using your pencil and thigh your going to put a curve into your card strips.
Put the card between your pencil and your thigh and pull the card through with one hand while pressing down lightly on the pencil with your other one.
You should get a nice curved card strip out of it.
The curved strips are going to be put onto your wheel edges.
Wrap around your wheel and leave about a 1/4" overlapping seem.
Then cut off any excess strip.
Glue it on with white PVA glue, using 2 nails pin the edge in place.
Your short 1/2" plates are going to be the tire treds.
Glue them down and pin each tred with 2 nails, placed about 1/4" apart all around the wheel edge.
Repeat this process four times.
Be sure to use your soda cap as a timble to push in your nails because your thumbs will be real sore if you don't.
To finish your hubs, you can add plastic sprue spokes, card strips, WHFB shields, or whatever gubbinz you have lying around.
I used sprue spokes for this one.