DIY multifunction "Small Cooling Fan", a large arc deflector frame, circuit fault (no-load speed is too high resulting in a short circuit of the inverter bridge burned) Delta FFB0812SH taken by sickle blades and extra-heavy-magnetic metal chamber (to solve the problems caused by bad vibration balancing), "Small Cooling Fan" split out of the brushless motor rotor rubber bonded NdFeB magnets and single-phase brushless motor stator DIY hand around two strands in parallel with the commutation coil, DIY as "Small Cooling Fan" brushless motor drive circuit (DIY external temperature sensor can be more precise temperature control in the best location).