This is just a simple design that can be used for a number of things. Most commonly the commercial equivalent of this is used to blow air or liquid over tools on CNC machines, drill presses, etc. I am thinking of using it as an articulated arm to hold camera flashes off-camera and run wires through the center. Anything is possible.

Feel free to post up modifications, as this is tweaked to the fraction of a millimeter for my specific machine to be exactly as tight as I wanted them to be.

Note: I break a few here and there when putting them together. This is to be expected, and possibly thickening up the "neck" would fix this. I print 3 x 2 using multiply so this isn't a huge deal to break one every now and then.

EDIT: I uploaded all three resolutions. The highest is what made the links in the picture, but you may have similar luck with the other two resolutions. Thanks!