I am building my own CNC router table. I am using a rack n pinion for the drive on the Y axis. I have two separate motors to drive this, one on the left and one on the right. I need them to spin the opposite directions to make the system work properly. I was told that I could do this mechanically or in the program. I am using Mach 3. I was told that I should use a 4 axis controller for the extra motor. How do I program in Mach 3 to make the y axis and the A axis to move in the opposite direction at the same time. I'm not even sure this is the right idea. I am using the Y controller to move the right motor and the A controller to move the left motor. I can not reverse the polarity in the motor and use the same controller this would overload the controller, so it was suggested that I use a 4 controller system.
I'm really not sure I understand the question at all... And I'm not a Mach 3 expert. There should be a way to set the polarity of the direction signal in Mach 3. Post that question in the Mach 3 forum. You can also reverse the direction of rotation of a motor by reversing the leads of the motor to the driver. Hope that helps, but maybe you can try to clarify the question?