Aluminium Profile Type Router - Initial questions

[AndyUK]

So I'm planning to use CAT6 cable I have already for STEP/DIR - do I just use the individual cores still twisted and leave in shielding for the run to stepper?

Assuming you mean between the AXBB-E and the motor driver rather than stepper, yes. Try to use differential signal connections if possible, one twisted pair for Step+ and step-, etc. Shield as much as possible, ground the shielding to the star ground in cab.

Also - what's the best method to join the fixed motor wiring /limit switches to CY cable - just solder and heat shrink over the top? if the CY doesn't run right to the motor (only 1/3 or so) is there any point grounding the shield at cabinet end?

That's what I did. Yes always useful to ground the shielding at the cabinet, otherwise it's just not doing much.