What does the motor rotor spinning

You can not make an engine built exclusively with permanent magnets, but had not worked properly leaving it we will explain what determines which way the electric motor will spin.

What makes the rotor spin motor is that it needs a torque to start your working, it means that this time the torque is normally produced by magnetic forces developed between magnetic poles of the rotor and stator, the attractive forces or repulsion https://www.mrosupply.com/bearings/radial-ball-bearings/320006_6205-2rsjem_skf-bearing/, which are developed between the stator and the rotor, serves to pull or push the movable poles of the rotor, thus producing the torque which the rotor will rotate faster and faster until the friction or loads connected to the shaft to reduce the torque resulting to zero.

And after this point, the rotor begins to rotate with constant angular velocity, and both the stator and the motor rotor must be until they are such magnetic forces between poles to produce the torque required to rotate the rotor.