Am I correct when i say..... I have a Golden Motor that has 46 motor poles. My motor pole count only goes to 14 on my CA. I must divide 14 into 46. I get 3.285. I take my wheel circumfrence which is 2023 and divide it by 3.285 and i get 616.
I need to set my motor poles to 14 and set my wheel circumfrence to 616 to get the correct speed reading on my CA.
the number for the pole count refers to the number of magnet pole transitions in the motor. AKA the Hall Transitions. that means the number of changes from "N" to "S" as the motor turns through one revolution. since the magnets in the motor are always arranged as N-S-N-S-N-S so a PAIR of magnets counts as one pole.
there are always an even number of magnets. so the guy who says he has 47 counted wrong. he either has 46 or 48. seeing that 48 can produce some rotor positions where it would be impossible to step to the next position i'll lay odds there are 46. so in his case the number of "poles" will be 46/2 = 23poles.
this exceed the allowable pole count of 14. but all is not lost. it can be compensated by reducing the wheel circumference by the appropriate ratio.
if Pc = Pole Count set into the CA, and Pa is the actual number of poles the ration will be Pc/Pa
Example #1 46 magnet golden motor with a 26" X 1-1/2" tire.
1. 46/2 = 23 poles
2. set poles inside the CA to any number we choose. in this case i will set it to 11. the ratio will be 11/23 = 0.4783.
3. my actual tire circumference is 2100mm. so i will set it for 0.4873 * 2100 = 1004
Example #2 Puma/BMC geared hubmotor with the same tire.
32 magnets and a gear reduction of 5:1. that means the motor turns 5 times for each revolution of the wheel.
1. 32/2 = 16 poles. but this is repeated 5 times for each revolution of the wheel. so actual pole count is 16*5 = 80 poles
2. set poles inside the CA to 8. ratio becomes 8/80 = 0.1
3. 0.1 * 2100 = 210
