Higher Power Interface

Sorry, I have put this in the wrong thread, I am trying to delete it but can't find how just yet.

I'm thinking of buying a small (compact) stepper interface, rated less than 2 amps per phase, but I want to run it on a 2.5 amp per phase stepper motor. Can anyone tell me if I can get away with just putting an FET on each phase?

I am CNC'ing a large'ish' Mill, so I need fairly powerful motors to run it. I know it is easier and simpler to buy a >2.5a rated controller, but this controller has button controlls so I don't have to boot the very slow, very old laptop to move the leadscrews (I also have mobility problems) The mill is a far eastern model purchased in the UK from WARCO, model ZX-15

I'm no expert when it comes to electronics so be gentle with me. Any information would be great

Ian