Originalmente inviato da ron_van_sommeren

Whether you use star or delta makes no difference, you can get exactly the same motor (Kv, Kt, Io, Ri) with both configurations: 17 winds in delta/triange is the same as 10 winds in star/wye (factor 1.7 = v3 ). (Wire diameter has to be changed accordingly of course)
However, delta is a closed circuit all by itself, differences between the wound phases (#winds, wire-length or -diameter) may lead to differences in the voltages induced in the coils/phases. Useless circular currents will flow through the delta circuit, which leads to higher temperature and lower efficiency.
Therefore: star/wye.


Higher efficiency does not only mean that the motor makes better use of the batteries' power, it also means the motor is able to handle a higher power input before hitting its maximum temperature mark.
An example:
Say the motor has an efficiency of 70% and it can handle 50Watt input. That means it can get rid off 0.3*50=15Watt excess heat. Now, by cramming in thicker wire, efficiency increases to say 75% (I'm a bit optimistic here). The motor's ability to loose those 15Watts has not changed (by radiation, convection and conduction). This means the motor now can handle 60Watt before it hits the 15Watt (0.25*60Watt) losses mark. An efficiency increase of 5% gives an increase in the power to weight ratio of 20% (from 50Watt to 60Watt). That's why efficiency plays such an important role, in any motor design: efficiency governs maximum power.