Hi
Is there any way to convert ERPM to RPM with no information about poles of motor. I want to calculate kv for my outrunner motor. I know kv = rpm/rated voltage. And in Vesc i only see erpm. I tried to calculate Kv from vesc terminal but it shows 0.0. I did it on foc mode.
Nope. You need to know either KV or pole counts to figure out one or the other. Why it's so hard to get the pole count? That's like the easiest thing to do.
NextGen FOC High voltage 144v/34s, 30kw (https://vesc-project.com/node/1477)
I don't have motor datasheet. It is a off course electric bike hub motor motor 24V 200W. How can i measure how many poles this motor?
faheemiftikhar
if it's a direct drive, probably the easiest low tech way is to spin the motor with a known RPM and then eRPM / RPM = pole pairs. You can also open up the motor and count the number of magnets.
NextGen FOC High voltage 144v/34s, 30kw (https://vesc-project.com/node/1477)
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faheemiftikhar
It is not direct drive, for 10% duty cycle i have erpm = 700 and rpm=14 (how many times motor rotate per minute) (erpm/rpm = 50 ?). I cannot open the motor because I do not have the tools. Is there any other way to measure poles? I need poles for Kv and Kt because I know kV = wnoload(rpm)/ rated voltage. I know the rated voltage is 24V. All I need is rpm (vesc tool only shows erpm). Can i figure out kv. When i run kv command in Vesc Tools i get 330 which is in erpm then same thing here i need poles to get in rpm.
faheemiftikhar
Lots of ways, not sure why you refuse to use google. If it has sensors, you can check the number of time the sensor transitions after one full rotation.
NextGen FOC High voltage 144v/34s, 30kw (https://vesc-project.com/node/1477)
Thank you
faheemiftikhar
Did you get it. Did you figure it out? You can spin the motor by hand and feel each magnet per revolution or you can run (move a magnet) around the outside diameter feeling for poles. So if this is too fundamental of an answer.
Hi, i figured it out. i followed this video and followed step by step and it worked. Thanks for your answer. https://www.youtube.com/watch?v=KjcFiPkLPKo&ab_channel=JayThuse
faheemiftikhar