Tom uses CAT 5 multicore twisted pair wiring in his printer: Good idea? http://toms3d.org/2016/07/14/my-biggest-3d-printer-yet-analyzing-the-cerbrisreborn-design/
No. I can think of maybe ten reasons why not, but maybe the most obvious if you have seen cat-5 cable is the type you buy on a reel to wire a building is not braided i.e. several thin wires per conductor but one thin (fairly fragile) solid conductor. There are strict limits for both pulling (when installing) and bending radius for cat-5. If say on the BB you were to use cat-5 for the wires running up the spine and in a loop over to the X-Carriage then this thin single conductor would be prone to breaking as this wire is not designed for continuous bending, quite the opposite it is intended for static installations. Fly leads the Ethernet cables you use to connect your PC to your router (if you don't use WiFi) may be different, I'm about to cut one open to have a look. But even these are not intended for installation where they are moving continuously, more for PC to router type installs. He mentiones the cable is cheap, that is because it does not use braided single conductors but a single thin conductor.
Patch grade is braided it's ok in high flex applications but not as good as ribbon cables (if the flex is in one axis) plus you have to watch the behaviour of twisted pair in applications that don't use differential signalling. If you are on a budget then it's a cheap source but it's not the best option out there from a technical perspective. The solid core stuff is used in installations because it performs better electrically (as well as being cheaper)
You guys convinced me. But now, as if in reply, Tom has come up with a video on wiring printers: http://toms3d.org/2016/07/20/how-to-wire-your-3d-printer/ He tackles the Cat 5 issues head on and makes a really good case.
