Originally Posted by Brutus1967
As far as I know, a coreless motor is not functioning on the principle of equal polarity magnets rejecting and opposite polarity magnets attracting, but on "Lenz's Law" that says that a straight conductor in a magnetic field, carrying a current, experiences a force perpendicular to that conductor and perpendicular to the magnetic field lines.
You're thinking of the induction motor I think.
A coreless motor is the same as any other brushed motor. Remember making a motor with a nail and winding wire around it? If you pulled out the nail and left only the windings, that would be a coreless motor. It is more efficient because of lower rotating mass.