Several RL events conspired to throw off my scheduled on the Ithorian costume. A work trip to Australia took 10 days, and then the worst cold I've ever had took another week. Reviewing my schedule, I've finally decide that I'm not going to be able to finish the Ithorian costume before SDCC 2014. I'm sad about it, but it does reduce the pressure and lets me redesign the costume as I run into problems and look for alternatives. Instead, I'll unveil it for the 2015 con season.
However, I'm not stopping work on this. The additional time just lets me make the costume even more awesome! For instance, I've been following the Giant Creature build by Legacy Effects, Stan Winston School, and a variety of partners. This week, they were showing off the mechanical controls the puppeteers will be using inside the creature. That inspired a new mechanical control mechanism for the Ithorian's head. Also, I've gone a bit overboard on images for this part of the build.
The key components in the mechanism are these ball joints that I bought at a radio-control hobby store. They are used for attaching control surfaces in model airplanes to servo motors. They're solidly built, have smooth movement, and are relatively cheap. I built them into "thrust rods" using threaded rod inside aluminum tubes with a ball joint at each end.
The steering arm is an aluminum rod passing through a 45 degree PVC joint. The arm has a threaded hole in the middle so that a bolt can hold it in place. Also, the ends are threaded so that the ball joints on the thrust rods are bolted into each end. Here's a more thorough sequence of pictures showing the construction.
The drive levers are mounted on each side of my head. They are made from aluminum stock and cut to size for my head. A pivot hole is drilled at one end and used to mount the lever onto the outside of the frame. There's also a threaded hole used to mount the other end of the thrust rods. These are the basic head movement controls.
A headband loosely attaches to the lever arms so my head motion can drive them. I sewed the basic headband from strips I cut out of an old t-shirt along with some Velcro fasteners, and then I attached EVA form for padding. Some canvas strips are sewed down to wrap around the lever arms. All of this was sewn with our old Necchi sewing machine (sorry, no pictures). That thing is a work horse. At the end, it had to sew through 2 layers of canvas, the EVA foam and two layers of t-shirt material. Tricky, but it got the job done.
The parallelogram structure of the overall mechanism translates my head motion to the head movements of the costume. It's pretty slick. Here are some pictures of me testing the rig. I was checking fit, range of motion, and looking for high friction joints.
The rig is comfortable and the range of motion is pretty good. The problem I found was in the azimuth rotation around the neck (left-right). I need to find a lower friction bearing. But overall, I'm very pleased with the movement.
Okay, one last photo. So far I haven't shown the outer structure. I've been making some major changes, so a lot of the foam structures I've previously shown don't fit anymore. Here's what's left of my original foam outer layer on top of the current mechanism. It gives me a feel for the proportions with my head covered. There's lot's of room under that "hump", so my head and all the controls fit comfortably. I'm pretty happy with the overall proportions.