Building the tank

Building the tank took two tries. The shape is generally a flattened cylinder, but it has a tapered section about 1/4 from the front. You can see the shape in this schematic the movie.

I made the first attempt without looking at this schematic, and the result was... poor. So for the second attempt, I compared the length of the cab's wheelbase in the schematic to the wheelbase of my cab, to figure out the scale factor, then figured out the dimensions I need my tank to be. Then I went to work and built this framework out of card:

As you can see I shaped the rounded end caps with sculpey.

Then came the fun but long part: paper mache. I applied wood hardener to this frame, then cut narrow strips of newspaper and used wood glue (the proper stuff) to layer strips over this hard skeleton of card.

This is the end result, after mocking up the tank's wheels and placing the other card parts (also made with my vacuum former) in their approximate positions.

I think this came out pretty good. I didn't sand the paper mache down, and left the slightly visible overlapping newspaper panels showing. This should make for some interesting texture later on.