(bipolar parallel connected) and 24 volt power supply. I have a controller configured sw1off, sw2off, SW3 off, off SW5, SW6 ON, sw7on, sw8 at (400 steps per revolution and 4.2a Output Current (A)). When the engines are not running hot but to pull more smoothly. I wonder what would have to change the engines would not be warmed and to run smoothly? I wonder whether the need for the controller and motors 48 volt power supply?