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Kv vs Turns in Brushless Motors

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Kv vs Turns in Brushless Motors

Old 07-09-2018, 04:41 PM
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Questions?? Kv vs Turns in Brushless Motors

Why are some brushless motors rated with Kv (3,900, 4550, etc) while others are rated by turns (17.5T, 13.5T etc)?
What's the difference between them?
Why two different ratings for the same product?
Is it the same product?
Are there equivalencies between Turns and Kv?

Thx
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Old 07-09-2018, 05:13 PM
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Originally Posted by JCG1
Why are some brushless motors rated with Kv (3,900, 4550, etc) while others are rated by turns (17.5T, 13.5T etc)?
What's the difference between them?
Why two different ratings for the same product?
Is it the same product?
Are there equivalencies between Turns and Kv?

Thx
That would be because most sensorless motors are measured in kv, while sensored motors are generally measured by turns.
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Old 07-09-2018, 05:17 PM
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Sensored esc/motor set ups are really smooth and instant, while sensorless seems to have a slight lag and are commonly known for "cogging" which is generally not preferential for racing applications. The rating is relative but that requires a quick google search on that topic.....sorry i don't have a chart handy. Hope this helps some.
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Old 07-09-2018, 05:23 PM
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Old 07-09-2018, 07:54 PM
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Awesome, very helpful. Just what I was looking for!
Thx
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Old 07-30-2018, 12:24 PM
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Originally Posted by JCG1
Why are some brushless motors rated with Kv (3,900, 4550, etc) while others are rated by turns (17.5T, 13.5T etc)?
What's the difference between them?
Why two different ratings for the same product?
Is it the same product?
Are there equivalencies between Turns and Kv?

Thx
The ultimate explanation
Brushless Motors: Kv vs. Turns - RC TRUCK STOP
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Old 08-04-2018, 04:10 AM
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Just because two motors have the same number of turns doesn’t mean they have the same Kv ratings, the same power, or the same wattage. One also has to take consideration of the price for quality components used to make a motor. That chart, a few posts up, is probably at the far end of maximum Kv rating scale. I have some 13.5T, and 17.5T motors that have some very different Kv "numbers" associated with them when compared to the chart, e.g., my mild 13.5T is said to be a 2550Kv motor, and one of my 17.5T motors is said to be 2250Kv. If I use those two motors in the same platform, the better quality 17.5T motor feels so much better than the cheaper/milder 13.5T when it comes to speed and power delivery.
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Old 08-04-2018, 05:07 AM
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A simple reason is to clearly define what motor for race classes.
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Old 08-04-2018, 11:04 AM
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kv is kv .. rpm per volt.
turns can be different from brand to brand or even time the came from manufacturer
had a big list years ago with actual rpms per volt on many makers
if your looking for a certain RPM then buy it to your needs
gave up on believing sellers kv rates
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Old 08-05-2018, 09:26 AM
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Originally Posted by Billy Kelly
A simple reason is to clearly define what motor for race classes.
no reason to do this what so ever. no need .he asked about kv and turns # nothing more
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Old 01-11-2021, 03:00 PM
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Originally Posted by JCG1
Why are some brushless motors rated with Kv (3,900, 4550, etc) while others are rated by turns (17.5T, 13.5T etc)?
What's the difference between them?
Why two different ratings for the same product?
Is it the same product?
Are there equivalencies between Turns and Kv?

Thx
​​​​​​ I'm trying to find out what I think you are aswell .I'm buying a brushless motor set and it says different kV numbers in its specs .how do I know what one I'm getting. Or is there a way to make it produce different kv
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Old 01-11-2021, 03:39 PM
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Originally Posted by Shell
​​​​​​ I'm trying to find out what I think you are aswell .I'm buying a brushless motor set and it says different kV numbers in its specs .how do I know what one I'm getting. Or is there a way to make it produce different kv
You will have to pick what kv # you want..
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Old 05-01-2021, 08:33 PM
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From a performance point of view, is it worth it to switch from a 17.5T 3000Kv brushless to a 13.5T 3200Kv (different brands). Will 200Kv difference be obvious?

TIA.
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Old 05-02-2021, 06:51 AM
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200kv on a full 2 cell .lets do the math.nope thats all you..lol 1600 rpm is going to make a difference. a 17.5 to a 13.5 you can see the difference from 1st takeoff along with a gear change so 13.5 wont over heat.
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