Printrbot Model 3 X/Y Axis cable chain support

Note: After several hours of printing with the Model 3, I'm not completely convinced this will be a complete solution to the issue. I've seen the cable sag slightly, and while it hasn't jammed yet I wouldn't put it past it to slide down. I'll leave this part up, but might try to design something that will attach to the bracket on the extruder.

The printrbot Model 3 has a horizontal cable chain for the X/Y axis - while it is affixed with two screws on either end (two at the extruder, two at th