i put a small bit of detail into how i would do it in my transforming clock thread over the the WIP area

but the way i see it no parts ever deform unless unless you have something like wires and pipes showing

the rigging of a robot (from what i can tell) is fairly different to rigging a human in the sense that you don't need to soft skin it, just use the old 3D heirarchic rigging ways
that is, you'd parent stuff to the bones rather than soft or rigid bind them

of course, it might be best to use parent constraints instead for something that is transforming. because if you translate those bones you don't know where their old position was when you move it. (at least i couldn't be bothered thinking of a way to do that. i'd just animate the parent constraints)

i think doing stuff with skeletons and constraints will be the best way to rig the robot. you'd probably want to use set driven keys and expressions as well

..yeah i was wondering what happening to your USB robot