Arduino Quadcopter motor control

the Arduino is under the left motor controller (note the micro usb)

I have found success with using the freetronics motor controllers to provide speed control and direction for my quad. I cannot stack the motor controllers on top of each other like I can with the arduino as each board has the same input pins on them so i have had to separate them out to get individual control of each motor. I will endeavour to make adjustments to the board so it will stack.