I think a clean and robust design such as the Orca deserves clean and robust cable handling.
Based on Rotoscans derivate of Landrus cable chain I puzzled a chain on all the axis of my Orca.
I made the holes 5% or so bigger so it moves easier.
I allowed some backward bending, which is not a good idea. This I repaired (untested!) in the uploaded files.
For the next derivate it would be nice if the links can be opened.
The links for the Y must be a bit shorter for a smaller curve. The links for the Z can be bigger.
I printed with a layer thickness of 0.3 mm with the 0.5 nozzle and 3mm filament. It moves smoothly after some playing.
Before printing check the squarenes of your X Y. Like Rotoscan pointed out. Use thingiverse.com/thing:12820 to verify that your prints are "Square".
For the X I used 13 links of 22mm.
For the Y I used 17 links of 16mm.
For the Z I used 14 links of 22mm.
The X carriage is easy mounted in the leftover hole with an M4 screw. The base is attached with double sided tape. Somewhere in the middle.
Y carriage is attached by removing one screw of the bearing holder. Slide over the chain end. Put back the screw.
For the YZ link you need to unscrew the M8 rod a bit. Put it on the rod and screw everything back.
For the Z screw the chain end to the hole(s) of (I think) the filament holder.
Rewiring your cables might take some nerves. That's why the next derivate should have links that can be opened: everyone is invited for re-design!