Soldering the connectors on the motors is not easy! You have to use an alligator clip to hold the connector in place. Find the hole in the side of the connector and use it to get the soldering iron into the center. This requires a fine soldering iron tip. Fill the center with solder. Stick the wire into the hot solder. I also bent the wire over so it fits tightly first of all. I should have stripped some more insulation off first.
I have mounted the Arduino on the drone and added a sensor shield to connect to the Receiver and the ESC's. Next to add the 6 axis accelerometer and gyroscope MPU-6050 module. So far I can control it and even tested out the motors.