Wich Size/Torque?

[samsagaz]

Well guys, i like 1 year without read this forum i really want to start ordering some pcs to start building my CNC Machine.

I really want to know how much Torque/A/V/Degree the Stepper need to have. I Really dont want to spend the money in small products or too big ones.

For example 580 Ncm will be ok for the X,Y Axis?

i want to buils and machine to just cut wood and maybe aluminium, and if is possible create holes in PCBs

The size of the machine that i want is 40" x 25" or a little small 35"-20".

Degree i think that need 1.8 (200 Turns)

Some of the Motors that i was looking at was

3.0A, 180N.cm, 1KG, 4 Wires
3.0A, 250N.cm, 1,25Kg, 4 Wires
3.0A, 280N.cm, 1.4Kg, 4 Wires.


Really dont know where to start :S

Exist any "formula" to figure how much torque i need with the size of my machine?