I'm wondering why this MAC motor is so difficult to drive for a controller.
Could it be because it has concentrated windings?
Do any of the other popular hub motors also have concentrated windings, or never?
The freewheel is in for something anyway, it greatly reduces the inertia in one direction only, maybe that confuses the controller.
Would there be still a better placement for the hall sensors? Maybe they get adversely affected by the changing magnetic fields there right on the edge of the stator. Bury them lower on the face of the stator?
Slot spacing for the sensors should be in multiples of 3, right? But what slot to use as the #1? (Assuming that we're gonna place the sensors into the slots)
If we refer to the winding scheme:
Placing the sensor between poles #36 and #1 will have varying magnetic fields constantly affecting the sensors.
But if the sensor is placed between poles #1 and #2, its electrical environment will be much more quiet because, due to the concentrated windings, the pole #1 is always of the opposite polarity from the pole #2.
If we're gonna place the sensors on the face of the pole, then pole #2 has the advantage because it is flanked by two poles of opposite polarity, always.
I didn't think about this during the time that my motor was dissassembled but it would be interesting to know where the sensors were placed exactly, by the manufacturer. Anyone has a MAC on his bench?
I don't know much about motor design but I wanted to get this out, just in case...