Ah, my favorite animated movie.

I decided to make a large (as large as my printer could print) copy of the Iron Giant’s head for my desk, with articulated jaw, teeth, and replaceable, and hopefully, lit-up eyes.

Here’s my progress: I ran a 12 hour print last night, and while the print turned out pretty good, sadly, it suffered stress cracks, which seems to be an inherent issue with ABS printing:

I didn’t help matters by how I modeled the crest. It’s like a knive blade stuck down into a groove of almost the same size. This pushes the head apart a bit more. Some adaptation will be required there.

But the main problem is that I think this filament needs to be printed a little hotter to get these cracks to disappear, and I’m not even sure about that, so when I’m done with this prototype completely, with hinged jaw and retracting teeth, I will reprint it hotter.

I may also be able to print it in PLA which doesn’t require a heated print bed, and may be less prone to stress cracking. We’ll see…

Here you see the space for the upper teeth. There are slots which will hold posts attached to the teeth so I can slide them up and down evenly. Hopefully.

There is plenty of room inside to add lighting:

UPDATE – NOV 10, 2015

Last night I printed the jaw, the teeth, and all of the pegs and small bits. I glued the hinge pins to the jaw, then pushed the upper teeth into the gap, glued the pins in place which allow them to slide up and down. Then I glued the pins into the lower teeth and snapped them onto the lower jaw, into similar grooves to allow the lower teeth to retract. (I will have to do some adjustment there, since my tolerances were off. Some cutting down of the pins made it fit for the prototype.)

Here you can see the lower teeth retracted, but still visible on the lower jaw. The upper teeth are fully retracted and hidden:

Here, both sets of teeth are fully out:

They are carefully designed to fit together perfectly.

All in all (except for those darned stress cracks) I’m very happy with this guy.

UPDATE: Nov 23, 2015 – Version One Complete!

This weekend, after some redesign, I reprinted the Iron Giant’s head. I noticed a ring around the head, just under the “nose” where the crest stops, and I think there’s a problem with one of my 3D printers. It has been consistently printing a ring about 1 inch above the platform, on a lot of my prints. I’m thinking there’s a worn part in the vertical arm which holds the belt. This weekend I printed the head on my other printer, and at a hotter temperature in hopes of avoiding the stress cracking you see here.

Then I printed a neck, and gave the neck two spherical bumps, and the head two spherical cavities, so the neck could slot into the head. The first attempt had the head too upright, so I tilted the bumps a bit to form ovals at a bit of an angle. The result was the ovals should have been spheres, for more flexible angling. This is how I had it planned originally, but didn’t think it would work.

Here’s some shots:

After I got this one assembled, I went to work creating the “repair summoning” crest. This crest is removable for a reason.

When the giant is hit by the train early in the movie, his crest opens, and a summoning beacon rises up, calling all of his semi-autonomous parts to return and be re-assembled:

So I modeled a new crest, with the aperture open, and the beacon:

Later, I will add rings around in semi-translucent glow-in-the-dark blue.

Oh, look, I did it: