anyone know how to figure out how to figure out the motor resistance in Ω

[Geogenesis13]

like it says does anyone know how to find out the motor resistance in Ω

[_paralyzed_]

if its a neu, feigao, medusa or lehner, go to BrianG's speed calculator, it will tell you the motor resistance

[BrianG]

Finding the DC resistance would take some special equipment if it's not listed. This is the resistance of a stalled motor.

And the inductive reactance will vary with frequency and rotor movement.

The DC resistance will always be VERY low, but isn't really useful for general calculations. For instance, a motor could easily have 0.01 ohms of resistance depending on the wind count. If you apply 14.8v to that, the current would be 1,480A. Of course, your batteries, wiring, and/or ESC could only deliver this for a few uS before burning up.

Just curious, why do you want to know this?

[hoovhartid]

When I wanted to know the same thing...it was so that I could plug the numbers into your calc for a motor that was not listed... lol

[BrianG]

lol. That makes sense I guess. The only thing that value does is show the kv drop for a certain amperage. It's really not all that important IMO because once you start getting that precise, ANYTHING can make a difference in speed (like drag, bearing friction, etc), and those other calculations aren't as accurate. I have considered removing that more than once because of this.

[SpEEdyBL]

If you know the resistance of one motor, you can calculate the restistance of all other winds. Say you have a neu 1512 1.5D which has 3300kv and 0.003 ohms and you want to find the resistance of a 1512 2.5D. To find the resistance, you just take the ratio of their winds 2.5/1.5 = 1.67, square it = 2.78, and multiply by resistance of the known motor and you get about 0.008 ohms. Since higher turn motors are wound more consistantly than low turn motors, expect higher turn motors to have slightly less resistance that what you would calculate and low turn motors to have slightly more resistance than what you would calculate. Now you can compare what wind feigao motor will be equivalent to your neu motor or vise versa, since two motors with the same resistance are considered equivalent powerwise, even if they have different kvs. And of course you get more power by going up in cell count with the same motor.

[Geogenesis13]

alright thanks for telling me and BrianG Hoovs right i just wanted found out how much so i can put it in your speed calculator