kelly killed 1 hall ???

[HAL9000v2.0]

skew is 1 pole pitch but ill say 1 slot pitch because windings goes through every forth slot, one circle of wires have two slots between. Number of poles is number of slots divided by 3, is that right ? 72 slots, 24 poles?

 

[The7]

skew is 1 pole pitch but ill say 1 slot pitch because windings goes through every forth slot, one circle of wires have two slots between. Number of poles is number of slots divided by 3, is that right ? 72 slots, 24 poles?

Thanks.
I think that you are right that it should be called 1 slot pitch skewing.

Tooth = coil pole
Pole = magnet pole

"windings goes through every forth slot, one circle of wires have two slots between."
=> coil wound around 3 teeth

"Number of poles is number of slots divided by 3, is that right ? "
It is right for your motor. (But not right for PUMA/BMC motors)

For X504
72 slots (or 72 teeth), 24 poles.
1 pole = 180 deg
1 tooth = 180 deg / 3 = 60 deg
Skew 1 slot pitch
A coil of 4 turns spans around 3 teeth.
24 coils per winding phase

The waveform of the BEMF in 1 phase winding looks like a trapezoid with a point-top as shown in the pic.

A 6-step drive would be deemed to be more suitable for trapezoidal BEMF motor.

Note: PUMA/BMC motors have BEMF closer to a sinewave than that of X5.

 

[HAL9000v2.0]

I we just did some current checking on kelly and it seems that up to 3 km/h (~25rpm) there is no current limit in speed mode and it was 97A about max that my SLA will produce. The adjusted % of current have no influence. In current mode there is limit linear with twist of throttle. I think this is the reason of overheating when I do lot of stop an go. When speed is stable even on high hills motor is completely cool. Just wondering is it a bug or a feature?

 

[HAL9000v2.0]

After installing NTC and second set of halls burned; I can see clearly that high temp is definitly a problem for halls.
Here ar some measured temps on different current limits.
This is highest temp. measured during fastest ride possible with adjusted current limit. cca 25 full stops and max accelerations.
current limit 30A in torque mode max temp 128°C inside coils
30A speed mode 106°C
40A torque mode 157°C
40A speed mode 124°C
50A torque mode 178°C (1 hall dead)
50A speed mode 149°C

As I can not find hall sensor that can stand higher than 150°C temps. I have idea to put optic or hall sensors on my disc break instead.
Question is will controller work with analog hall sensor so I can make some kind of sinusoidal curve on edge of my disk and fine tune it with position of the sensors.
Of course optic sensors will work only as digital.

 

[docnjoj]

Wow! Those are some high temps! F degrees=c *1.8 +32!!!! Well over 300F for the Hall death! Does Dr Basses get that high? He mentioned heat problems in stop and go traffic.
otherDoc