Can I calculate the (kv*) of this motor?

ESK8 Electronics
1

Hello everyone,

I’ve had my eye on this motor for a little bit now, however they only show the power in Watts. Every esk8 calculator I have tried required a kilovolts rating for the motor. How can I calculate this?

Thanks for the help!

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@b264 knows the math for this shit lol

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@b264 Please help o mighty math god. I make offerings of skateboard bearings and hub motors :pray:

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no load rpm is 629 at 60v, according to chart. that would be 629/60 = about 10.5 kv

btw, I love how badly named kv is!

also according to chart, max torque is around 441 – that would be your likely max speed. so 441 rpm * circumference of about a meter gets 441/60 M/s = about 7.35 M/s or 26 kph/ 16 mph when running a 60v system

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Thank you! Doesn’t that seem like quite a low value however? Most 6374 motors and even some other hub motors are rated at 75kV. Since this is a scooter hub motor I thought it would be more powerful.

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there’s a reason we need to use gearing to slow down these motors, usually. Kv is not a rating of power, it’s theoretical max speed.

Watts is what you are looking for for power. looks like it’s a 1800 watt motor. ballpark equivalency is 750 watt = 1 hp… so that’s about 2.5HP

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Kv is how it is rated for speed (rpm/volt)

kV is kilovolt

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Ok so might be a dumb question, on a calculator like so https://calc./#/0

What would I input for the drive trail values? I understand Id need to put in 1 for motor and wheel pulley, but what do I put for the kv and poles values?

Thanks for helping me through this. Also from what the company has told me, this motor can only be configured up to 600W.

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Fixed the title

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technically it’s the reciprocal of the back emf constant, Ke. we should call it the volt constant of a motor. everyone just says kilovolt. that’s why I’m amused by the name RCers and eSK8 ppl use for Kv

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you can’t, the data isn’t provided. if you leave it at 14 poles it will still be in the ball park.

254 for wheel size. 10.5 for Kv

plug in what battery data you are planning on going with

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:pray: Thank you once again :smile:

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quite welcome, I’m stuck waiting for a slow data process at work.

when that happens, I go around a couple of forums and stackoverflow and answer what questions I can

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Close. :smirk:

Kv is approximately rpm per volt

kV is kilovolt

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I got a similar number based on their ratings which may or may not have marketing department exaggeration, but it’s similar to what @olestra got

I would actually recommend asking them, and letting us know too :slight_smile:

Also with a Kv that low, hall sensors will be very important, so make sure those are present.

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Thank you, will check this! Do you think this is powerful enough to run a longboard with a 10s5p setup? Or should I go for something more powerful.

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I would definitely never use that motor for a longboard because it’s too big.

If you were trying to make a single-wheeled skateboard (Onewheel-style) that might be another story. I’m not sure what you want.

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Its kinda hard to explain, basically something like this:

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In that case, it may be a fantastic motor choice

You’re going to need to run fully sensored so make sure the sensors are good and you get them nice and waterproofed after you receive the motor

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Ok awesome, just wanna make sure it will actually move me before I buy it :sweat_smile:

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