Quick Update;

I've decided to go with a 1:1 ratio for now (which was always the intention) but by designing in the pulleys, I'll have the option for change in the future. This means that the dual 4.0Nm on the X should do okay, and despite the overkill, I've gone for 3.1Nm on the Y and Z (thinking being if I have issues with one motor, I'll have an identical one to swap in and out for troubleshooting).

I've also done a lot of investigation around motor drivers, and have ultimately followed Neale's recommendation with the EM806s - they seem to tick all the boxes for me and the stall detection is a really big draw. That, and Zapp's sale means they're very reasonably priced! (£62/ea rather than £105-£110/ea elsewhere).

Still quite undecided about breakout boards / control boards, although I'm moving further away from the CSMIO offerings. Watch this space!