Just a quick update on Cymon, Before I resized the pieces I wanted to come up with a new joint that would be easier to use, hold strong, connect easy, disconnect easy, and print well. 3D Printing for Architects had some information on tolerances and fittings that I had never seen before and helped guide my design until I found a hinge I liked.
The trick was this sort of wedged design for the hole that held the ball at it's widest completely but didn't engage the ball when assembling until it was absolutely necessary. I also blunted the edges of the source circle so that there was a built in area of wear to insure the joint remains stiff for a long time. I don't know how much weight it will hold, but I'm sure it will hold a little more than last time.