Hi all :D
I recently saw one of my favorite animated movies again, with one of my favorite robots, The Iron Giant.

And I thought I could build the head of the robot remembering the last scene of the movie.

Below I will show you how I built it using basically an old fire extinguisher and basic tools.

Supplies

Materials & tools

An old fire extinguisher
2 Screws with nuts
A hacksaw and a coping saw
A dremel
Sandpaper

Step 1: Templates

Here I will leave the plans with the views of the head.

These plans are made for the extinguisher that I got, which has a diameter of 11.58cm. If you need in another measure, you can scale it.

Step 2: The Fire Extinguisher

I know that the robot in the film is made of iron (obviously) but the extinguisher that I was able to get was aluminum hehe. However, this material was perfect, because it is easy to work and also because it is thicker than steel, which gave it a better final shape.

As you can see in the picture, the extinguisher that I got is a bit conical, so I had to work on this.
First cut the nozzle, then with a hammer I gave it a dome shape, taking advantage to make the hole a little smaller.

Step 3: A Very Important Detail

To avoid inconveniences, I made in this step the famous head bump of the robot.

I used a metal sphere that I had at home, I drew the area according to the templates, a few hits withe the hammer and its ready.

Step 4: Base Part

First I cut the base part of the whole head of the robot, then I drew the cutting lines on its back and then cut using the coping saw.

Step 5: Cut the Jaw

As in the previous step, draw the next part on the extinguisher and cut it off.

Step 6: Give It Form

As you can see in the plans, the front part of the jaw is flat, so following those lines I made a slight cut so that later I bend the piece along these lines, and with the hammer flatten that area.

Also you have to flatten the part of the joints of the jaw, to give it the rounded shape

Step 7: The "mohawk"

For this part I made a cardboard template using the plans, then I tried it on the piece until it fit perfectly.

With this piece I drew the shape on the extinguisher and cut it out. Then I just had to flatten it.

Step 8: The Eyes Holes

Now draw the holes of the eyes and then cut them using the dremel.

With the dremel I first marked the outline of the eyes as deep as I could. Then I made two cuts in the shape of a cross, then pry and take out the pieces that I do not need.

Step 9: First Look

At this point this already remind me the robot of the movie.

Now it's time to remove all the paint. I tried using paint remover but it did not work, so I tried to burn the paint a bit and then sand it, the final finish seemed interesting to me, so I left it that way.

Step 10: Joining

Having ready the parts we can begin to join them, the "mohawk" I joined using epoxy, on the internet I read that tin can be used but I have not tried it, it sure is much better.

To join the jaw, put it in place and mark the points and then drill with the proper size, I did not get the allen screws so I used hexagonal head screws. If you want you can cover the hole in the head with more epoxy.

Step 11: More Details

At this point the head is already finished, but we can add a few more details. Trying to imitate more the robot of the film, I stuck a rubber ring that I found at home inside the holes of the eyes, and below that a sheet of translucent plastic. Improvisation! :D

If you want you can also add lights inside, they look great.