Some other notes about this project- I used tin snips on the cans, which tends to create small and very sharp aluminum splinters. Be proactive in your cutting to avoid creating these, and when you are trimming, be sure to track them and dispose of them. They are not the kind of thing you want laying around to step on or stab your hands with.
Also, I chose to eyeball everything, so I can't really provide measurements for you. There were a few reasons for choosing to do it this way. First, the drawings of Robot that I based my modeling on are very imprecise. Except for the head being pretty well cubed, it looks like he would have been designed by hand too. Thus, the head was the only part that I made a template for, and I still just did it by hand after my template was a little too big for the body I had created. Also, trial and error by hand is more fun, and allowed me to do things like shorten the legs, and giving the final result more of a sculpture kind of feel rather than something like a molding. The imprecision will also give your final product more of an organic feel. Want to build your own? On to step one!