A cable chain bottom link which screws onto the printrbot left Z motor mount.
This is for the basic plastic version with my improved stepper mounts/bases.
I've made many variations and left them in the SU file.
I really had to loop the chain to the side because other positions confict with my custom framing.
The chain is now in use but having used it I think an open (non-enclosed) system may be better (printing one ATM).
This is the bottom and top for a chain made from http://www.thingiverse.com/thing:11978 by RotoScan.
You should be able to use two longer screws into the stepper to attach it.
The chain will be at the front left.
If you don't have my stepper mounts you can probably screw into the stepper but I would recommend the more stable bases - http://www.thingiverse.com/thing:28557
I plan to use the chain to go to the Z-stage but not to the extruder.
If you want to go to the extruder you need to use a different part set - look in the SU file.
My chain has the two movable bottom links reversed compared to the rest.