My quadcopter is newly built and out of a kit, but it flips on takeoff, its a LHI QAV 250 quadcopter, i have checked the blades and they are on the right way, the motors are all hooked up correctly and spin the right way. The main problem is that they start out at slightly different times, motor 1 starts before the rest which flips the quadcopter. Does anyone know how to fix this?