Metal Monster

I've decided to try to build an armature - some of it will be made of scrap metal, and some from parts that i'm buying. I haven't settled on a design, but the idea is to build it with adjustable joints so that it will be a fully articulated armature that I can use for a stop-motion animation. The creature will be 3-4ft tall, and i'd like it to be able to support its self without a platform at its feet.

The first challenge here is to find the proper joints - they need to be adjustable, made of steel (or maybe brass), and large enough to support the limbs/parts of the creature without slipping under its weight. I couldn't find a joint that would work for this online - not one within my price range, and comprehension. So I've decided to implement techniques used to build small metal armatures, but on a larger scale, and I'm going to make them from scratch. These are ball and socket joints.

I just ordered a box of steel balls from McMaster-Carr. Here's a photo of the joint i'm looking to create, but on a larger scale.