I broke my Motor mount by trying to pull the filament out cold. (Derp) The files on github were too old, and the files I got from MakerGear support were too new so I editied them to match my originals. I changed the wire tube ID to match the top and removed the side hole as well. Motor mount has the larger hole spacing for the mounting screws which matches my older gen linear guide. Print in ABS with heavy infill. Pick one top or the other. See source link for more info on setting up the cable chain mod.