Optimus Prime's back (unfortunately) isn't flat so I had to get to work constructing a box for it. Nothing too difficult here, though I did want two sides to be at a 45 degree angle. Cutting styrofoam like this is a pain, hence all the nice big gaps. I cut two rectangular pieces for the top and bottom, and a large piece for the actual back itself. Below is a picture of the first side getting glued...
... and here is the other side.
Below gives you an idea of how Optimus Prime's back box should look. I'll need to flatten the bottom edges to fit flush with the back.
I cut out the wrist plug (sounds erotic!) and the pieces of foam that will act as supports for it all.
I did a dry fit and all looked okay (ie no huge gaps).
Here's the arrangement of the styrofoam blocks that will add strength to the glue joint for the wrist plate. The actual piece that comes out (to let my wrist through) won't be glued. It'll just sit snug in place by friction.
I had to put the removable piece in place but did *not* glue it here. The only reason that piece is there is to glue the newly placed block of foam on the right hand side in place at the right distance from the front of the arm. There is glue on the block, placed at the top so that if it drips down it won't bond the removable piece in place.
I also painted the shoulder and the newly completed forearm:
And here's the bulk of the painted pieces lined up next to eachother: