Just like the battle droid in the movie, the model collapses into a
ball. It is virtually impossible to describe the complex process
of folding the model in words. The rear leg folds upward and is
linked to a mechanism that causes the tail to fold and spiral forward
and inward. The stinger folds in. Once the tail is folded,
the arms can fold back and lock into place with a couple of ball
joints. The forearms fold back at the elbow. Finally, the
front legs fold up toward the tail. In this configuration, the
model is fairly round and can actually be rolled. The protruding
red axle connector on the top triggers release of the front legs.
Once deployed, the front legs prevent forward rolling. The impact
of these legs on the ground triggers unfolding of the rear legs which
then releases all other locked features. The rubber bands pull
everything into place. When it works, it is incredible to
watch. Implied in the above is that it does not always work.
The rubber bands need to be just right, the rolling motion needs to be
straight, and a hard floor surface is needed.