Difference in motors

[Vihaan]

I purchased the following motor E-BIKE BRUSHLESS DC GEARED MOTOR 1418ZXF 48V 450RPM 500W and below are the specifications

which is a smaller motor compared to hub motor, so that i can test some of the functionalities, but i am finding it different from the hub motor.
The first step itself of detecting the number of poles i am failing, as per the manufacturer it is 8 pole motor, and i tried to rotate the motor with hand, it is hard to do the hand rotation and the number of hall transition in one mechanical rotation is high compared to 8. How do i calculate the number of poles of the motor?

 

[Diggs]

the number of hall transition in one mechanical rotation

Are you rotating the motor or the output shaft? If the output shaft then every rotation is 6 rotations of the motor itself.

 

[Vihaan]

i am rotating at the output shaft.

 

[Vihaan]

Yes perfectly i am getting the 48 counts in several iterations, thank you very much for the clarification.
I have couple of questions
a. When rotating with hand sometimes the output shaft rotates freely and sometimes it is very hard to rotate, why such a difference in behavior?
b. Regarding the back emf for me it was told to be sinusoidal back emf but when i captured using the differential probe between two phases this is what i got

Can i consider the above as sinusoidal what are the transitions in between?


Hall transitions i could not capture the 48 pulses at one time.