The discovery of the knob-and-nuts joint
Building a life-sized, fully poseable and animatable robot dog is not quite as simple as it might seem. There aren’t a whole lot of resources or tutorials on the subject, either. For a while, I thought I might find some guidance from the strange subculture of Halloween enthusiasts who build life-sized poseable spooks for haunted houses. But the joints on those guys aren’t designed for animation, and after umpteen million tiny rotations, they’ll get loose and stripped. That’s why the tightening mechanism is separate from the joint’s rotation mechanism in professional animation armatures.
Nice as those little readymade armatures are, they aren’t suitable for what I’m doing, which requires, as I said, a life-sized robot dog. (I should mention that the script calls for a pretty crappy-looking, jerry-rigged robot dog. So my lack of manufacturing skill isn’t a liability.) So the first thing I needed to figure out was how to make the joints.
So I did what one does with a puzzle like this: I wandered around in the hardware store aimlessly until the solution popped out at me. In this case, it popped out in the drawer and cabinet section, where I noticed that one of the cabinet knobs (number 322) happened to be a perfect sphere. I thought of the 10mm locking nuts I’d just been looking at, with their little built-in rubber washers, and I knew I was onto something promising.
So far, the joints are passing all my tests with flying colors, although it’s still too early to tell how they’ll hold up under the weight of the whole model, or how they’ll perform in the animation studio. I’m cautiously optimistic.
And yes, I’m aware that it sounds like something you’d find in a headshop in the red-light district…