Newbie- Stepper motor questions

[Garage Elf]

I'm doing my research on what will be my first CNC build and have a haunting problem about the stepper motors: you can harvest them from old equipment, buy them used or new. So:

do all 3 motors on a 3 axis machine need to be the same to for the cnc program to run or can they be mix and match?

do you typically need to enter the variables into the cnc program, like details of the motor (degrees, phase, amps, oz, etc) and the drive mechanism (thread pitch) so the machine will be able to drive the tool correctly?

Any input would be appreciated.

[arizonavideo]

If you want use ones I have three 200 OZ round Nema 34 for cheep.

Send me a PM.

Dave

[kawazuki]

IMO - motors on the X & Y axis should be equal to provide equal cutting forces during curved or vector cutting, Z can be equal to the others but is usually greater to cope with the heavy milling head (on milling machines obviously).
Motor details are irrelevent to the CAM package as all it outputs are strings of pulses - you set the parameters on how it translates a measurement into the pulses ie. Motor steps per rev = 200, leadscrew pitch = 16tpi so CAM would have to output 3200 pulses to move 1 inch. If the motor stalls, then it is either too small or you are too greedy with your cutting depths or speed of cut!