Cable Chain Remix for Pro Operation

This is a remix of spauda01's http://www.thingiverse.com/thing:1167746 to allow the chain to operate as per how they are installed on industrial equipment - the two 'legs' of chain run parallel with a single loop at the far end which constrains the cable to a certain diameter of bend.

To do this required the ends remodelling slightly to allow correct orientation, and the positioning is now such that it fixes to the rear of the rails to allow unimpeded motion and the required space above for t