Was about to get a toy- then I did some research...

[Juranovich]

So a 1.25:1 ratio would be like a 12.8mm pitch which at 750rpm would give 9600mm/min which is a nice area with good amount of torque.
[...]
Spot on, on both accounts, except using the motor calculator. The key to speed is low inductance motors with plenty of volts wired in parallel.

Just to get my head around this- if 1m/min and 750rpm are good values for general wood working, what would be the sweet spot for detailed work (eg 3D engravings in wood) or the occasional aluminium job?

With regards the stepper size- what would be the optimal torque rating for the machine to be balanced (considering the consensus seems to go against 2.4nm)?

On a side note- thank you for the detailed discussion, since I’m new to this it sometimes feels I’m designing blindfolded as I don’t even know what parameters I should be aiming for!