This guide stops the thick z-axis cable from pusching things of the table.  Contrary to the previous model it is mountet to the printer with the already existing screw.

Printing:

Print with the top facing down. Use supports for the overhanging part. 

Mounting:

Remove the screw at the bottom of the z-axis. Pull the cable through the slot. Push the guide on and fasten the screw again.

If i got time i will improve a few things (feel free to do it yourself and remix this thing), but it will work just fine.