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KV stats

PostPosted: Mon Jun 14, 2010 12:46 pm
by jomarx
Its me again, now for new questions:

1. Motors are rated in KV, is higher the better? Does higher KV means higher torque?
2. How can I determine if the KV rating of the motor is 'too much' or 'too low' in a setup?
3. And also a general explanation of KV :D

Thanks in advance.

Re: KV stats

PostPosted: Mon Jun 14, 2010 4:43 pm
by Mr Ed
The KV rating is the rpm the motor will turn with 1 volt applied. The higher the KV rating the faster the motor will turn and the less torque it will have. For a prop driven plane you want a KV rating around 1200 or less and the bigger prop you want to turn the lower the KV should be. Lower KV=lower rpm=more torque. If you want a high speed motor for a high speed airplane, then a higher KV motor will be needed and a smaller prop should be used. For a normal sport plane, you should look for a motor rated around 1000 to 1200 KV. For a 3D plane maybe something like an 800 to 1000KV should be used. For a FAST plane look around 1500 to 2000KV. Anything higher then 2000KV would more then likely need a gear reduction to work right. High speed motors are normally for cars and choppers that have a gear reduction built in. For a high rpm motor for an airplane, you would need to add a gear box. Hope this helps.

Ed

Re: KV stats

PostPosted: Tue Jun 15, 2010 12:23 am
by jomarx
WOW! 3 questions answered in 1 paragraph! thanks a lot!

Re: KV stats

PostPosted: Tue Jun 15, 2010 8:39 am
by siang
I've asked this question many times b4. High KV like 2W-20, I use to run that off my funjet with 80A or maybe it's 100A esc. People at club advice me against but LHS and funjet thread recomend it. I went for it anyway as I've bought it, seems alright except it got too fast for me to handle. Is there more to it than kv when selecting a motor, esp for speed?

Re: KV stats

PostPosted: Sun Jun 20, 2010 10:58 am
by ballsey
The higher the Kv the faster is will fly. I have a wing that had a 2000kv motor and was quite quick, put a 4200 Kv motor in it and it scared the pants of me. Gone back to 1900Kv lager Diamiter motor but am using a larger prop. still about the same speed but low amps now. Went from 40amp back to 25 amps on the new motor.

I'm not familar with this motor, but with most of my setups knowing what the Amps and Watts for the motor is a good place to start. Using a Watt meter (this is a must have item) will save you alot of money. Less chance of over amping your motor/esc/ and battery. As long as you check your set up and stay withing the tolorances of your gear you should not have any problems. Not sure if this much help.

Re: KV stats

PostPosted: Fri Jul 09, 2010 9:01 pm
by Jacko
http://www.parkflyers.org.nz/modules/ne ... =4&forum=3

I wrote this awhile back, should explain it all hopefully.

kV has no relation to torque.

Re: KV stats

PostPosted: Sat Jul 31, 2010 5:49 am
by Mr Ed
Jacko wrote:http://www.parkflyers.org.nz/modules/newbb/viewtopic.php?topic_id=4&forum=3

I wrote this awhile back, should explain it all hopefully.

kV has no relation to torque.


Your right, I meant to say speed. Sorry bout that.

Ed

Re: KV stats

PostPosted: Sat Jul 31, 2010 7:24 am
by baner