Kv Ratings on Brushless motors

[sweetdiesel]

Hey Guys,

I made a mistake earlier today by mistaking a 4300Kv motor for a 4.3 motor, therefore thinking that that motor was hotter than a 5300... of course which I mistook for a 5.3 motor. I have also found out that Novak, the brushless motors I am the most familiar with, used to classify there motors differently than they do now.... ie. a 4.5 motor is hotter than a 6.5 motor. So I guess my questions are... how do you find out how many Kv a motor is? What does this number mean?, and How do you use it to figure out if it is the right mill for your application? Thanks

Tom

At this time there is no consistent nomenclature for brushless motors. You can compare numbers within one manufacturer but it all gets thrown out the window when you compare two different manufacturers. I would look at the actual Kv rating, can size, efficiency, and how many cells are used to figure out which motor is right for your application. Unless you are a very good racer, a 3.5 or 4.5 Novak motor is better suited for bashing. I've gotten smoked by a guy running 19T brushed motor when I was running a LRP 4.5 in my Xray T2. Remember speed means nothing without control.

The lower the number on the Novak systems, the faster the car will be. The 3.5 Velociti has a Kv rating of 10500 revs per volt, while the SS 8.5 Pro runs only 5000.
You can get 2.5 turn motors but the quality of Novak sees no real difference in the REAL power results.

Actually this is somewhat untrue. The lower the number on the Novak systems within the same series, the higher the maximum rpm the motor will spin with a given voltage. You can make your car have a higher top speed with a lower Kv rated motor with more voltage. Also if your batteries are insufficient in handling the amp load of the higher Kv motor your car will accelerate slower.

Also with regards to a motor running "only 5000" rpms per volt, with a quality 2S battery you're looking at 35K rpms max which is pretty damn fast.

Spot on again Charlie, but I've never understood how you can TUNE an electric motor.
I though electric either worked or it didn't!!!!!
(not real clever but I can lift heavy things)

Some brushless motors can be tuned, as some manufacturers will allow you to change the timing on the motor.

You can get 2.5 turn motors but the quality of Novak sees no real difference in the REAL power results.

Real power results are easily recorded by using a wattmeter. It would also be pretty easy to see the difference between a 2.5 turn motor and 3.5 turn motor from the same manufacturer given the same can size, batteries and gearing.

 

[CharliesTheMan]

Thanks SD, that cleared up several fuzzy issues all at one time.

 

[platgof]

There needs to be a std for all motors, such as rpm, voltage draw, run time. I am sure more info could be added, but that would be a good start.

 

[gensace]

Check out this video to explain what is KV in a brushless motor

[ame="http://www.youtube.com/watch?v=RmrtV8YHSFY"]YouTube - ‪Understanding KV in a Brushless Motor‬‏[/ame]