Newbee looking for advice

[JAZZCNC]

1. what sort of torque or power will the motors need to rip half inch wood at a reasonable speed while leaving room to re-purpose as speedy motors for plasma - any suggestions please
2. id rather buy a kit form motor/driver set for the four axis like you see on ebay, but thats why they're on ebay right?
3. the lead screws or ballscrews is a definite advisory item which i am told that will lend efficiency to the motors?

#1 3nm motor stepper motor will do everything you need for machien this size but that's not what will limit your DOC it's the spindle and the strength of the machine. Also Chip clearence is required for large depth of cut else you'll get burning and excess tool wear.
Also there's more to stepper than just Nm size. Drive quality and Voltage they are run plays huge part in performance.

#2 Waste of money. For good machine you need balanced system and these kits don't offer this. There more than just power to consider when buying steppers. The spec of the stepper affects the Voltage required. Motors with high inductance will require much higher voltage to get the same speed and torque as lower inductance motors.
Voltage plays key part in the speed and to some degree torque you'll get from motor. These kits have Crap drives with low voltage supplies with high inductance motors. Hence why there cheap.!

#3 Forget lead screw they will be nothing but hassle. Ballscrews from china are cheap and easy got so not worth not buying. There's no comparison between them it's no brainer.

#4 I know there's no 4 but i'll throw this in for free.
Don't use twin motors drive the screws with belt drive connecting them together. Saves on money and much more reliable, completely removes any chance of racking.