Correct wire size for servo/stepper motors ? Dummy question

[dazp1976]

This has got nothing to do with current and everything to do with Signal and cable quality.

Cat5,6 or 7 is completely the wrong cable for this application and will cause him nothing but trouble in time. Ethernet cable is not designed to constantly move inside cables chains and over time it will break. It's fine in the control cabinet or if fixed to the machine but BAD for moving axis and cables.
Andrew:

Forgot about the chains.
My Cat7 (solid) go from rj45 modules 'attached' to box + machine, then connect to stranded (24awg) from there to equipment. You can get stranded Cat6A but I do use standard wire goimg from the cat7 to the various sensors etc.

However. I forgot about Igus.....

Chainflex CF10
(8x0.25)C (8core) For control. 0.25mm
(3G1.0)C (3core) For power transmission. Or (4G1.0)C (4core).
https://www.igus.co.uk/product/1015?artNr=CF10.10.04
https://www.igus.co.uk/product/1015?artNr=CF10.10.03
https://www.igus.co.uk/product/1015?artNr=CF10.02.08

I doubt their quality will be disputed (at a price).

I was trying to give you cheaper options because you may yet end up ditching these built ins after a bit but.....
If you're going to do it properly I'd suggest you go to Igus. They have loads of different options.

https://www.igus.co.uk/chainflex/unharnessed-cable
https://www.igus.co.uk/