What is the effect of motor winding end turns on torque for small DC brushless motors.? Many state that end turns have no effect on torque and that the only influence is from the winding portion in the stator slots. My belief is that because the end turns on small brushless motors are still within the influence of the stator flux, they still play a role. Others use the Lorenz force on a rectangular conducting current loop to demonstrate that there is no net force on a conducting current loop from its end turns, only the outer ends of the loop, but fail to realize that force isn't torque. Torque requires a moment arm which in the case of brushless motors is equivalent to the end turn length. Since torque is proportional to the winding area which is equal to Area = slot length X slot width = slot length X end turn length this demonstrates that end turns are a factor in creating torque. From many sites, torque on a conducting loop in a constant magnetic field https://www.boundless.com/physics/t...urrent-loop-rectangular-and-general-561-6351/ Torque = NIAB where N is the number of turns, I is the current, A is the Area, B is the magnetic flux. Since Area equals Stator Tooth Length X End Turn Length Torque = N X I X Stator Tooth Length X End Turn Length X B which clearly demonstrates that Torque is also dependent on the end turns and could contribute as much as the slot turns. Many disagree, but my feeling is that they have been conditioned to this because of the stacking of end turns on large industrial motors which have end turns outside the influence of the magnetic core flux unlike small brushless motors the end turns of which are still under the influence of the stator's flux. From a purely empirical approach, if the end turns are not involved, then motor efficiency would fall drastically if half the windings were not contributing. Many brushless motors have maximum efficiencies approaching 90% and if the end turns were not contributing, the I squared R losses would be very large. All DC brushless motors would be designed with extremely long stator teeth to minimize the percentage contribution made by end turns, yet pancake motors with 1:1 slot to end ratios can have extremely high efficiencies. My question is, who is correct, those who feel that stator end turns on these small motors do not contribute to motor torque or those who do?