You could do several bends, and cut and fold pieces under each other, to make something "curved", but it would be near impossible to make a smooth dome with cardboard. Your best best might be paper mache on a balloon, or find something else that's already that shape and use it (like I did with the baseball cap).
I've only just seen the 19 sec. of the video and already I'm excited. Your costumer looks amazing, but what really captured my attention was your Snoopy ruler. Why? Mostly because I have one exactly like it that I got in 2nd grade about 22 yrs ago. :)
This is incredibly creative. Not just recycling boxes to make the costume, but figuring out how to make it all work. Did you ever take any kind of architecture or art classes?
Awesome job, good for scaling and making a larger more detailed and permanent one later on too. Head is a bit large, but that's human physics vs. Trasnformer G1 body types ( humans not nearly as boxey). Goatta warn ya though, crazy glue doesn't last very long, it dries up and becomes brittle. Keep going, it can only get better from here, stay creative.
AUTOBOTS TRANSFORM AND ROLL OUT! Well done!! that's some creative mind you have. looks awesome. Do you have anymore video of you in the suit walking out in the public? I love the reactions from people. I'm actually building a Batman Arkham asylum costume for next year. I put aside $1500 to make it as genuine as possible..hardest part is to find the suit fabric. I found the leather for the belt, and I've started to make the gauntlets using styrofoam, duct tape and resin.
I had my Optimus Prime costume in 3 days ready. XD And, besides, now I is to be made a Soundwave Animated costume. Till present I have sat 18 hours in it. Only the helmet and then I am also ready. On the whole, I would become I will say for the whole costume of Soundwave Animated approx. 3 - 5 days. Because the helmet gets approx. 5 layers (shifts) Pappmaché. If I make this, nevertheless, with gypsum, I need (require) only half of the time.
Where did I get a few hours at night for a few days to put this together? I dunno. It's a thinker, that's for sure. There are, however, 24 hours in a day... And if you doubt my ability to get chicks, I simply ask that you watch the video of me in the costume at the theater and rethink that statement.
Yeah, that stuff on your shelves? One day your gonna walk in a it will all be gone...'CUZ I'M GONNA STEAL IT ALL!!!! BWAHAHAHA!!!! Anywho, thanks for the tutorial!