similar motor: Hi or low kv ??

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Hi there

Just for my future refernce,not thinking about a specific plane.

In general, for say a park foamy

Say, just for an exampe: I need a 15A motor.

Do I get say a 900kv or a 1700kv, given they are both same size & same rated power

the lower KV will be able to run bigger prop, but spin slower, higher kv will run a smaller prop at higher revs

So does that mean that both will give the same thrust ??

Which is the better choice

Cheers

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steverb Members Profile Send Private Message Find Members Posts Add to Buddy List Platinum (NZ) USERID: 280280 Newbie Joined: 01/Nov/2009 Online Status: Offline Posts: 17	Quote Reply Topic: similar motor: Hi or low kv ?? Posted: 09/Jun/2012 at 9:29am
	Hi there Just for my future refernce,not thinking about a specific plane. In general, for say a park foamy Say, just for an exampe: I need a 15A motor. Do I get say a 900kv or a 1700kv, given they are both same size & same rated power the lower KV will be able to run bigger prop, but spin slower, higher kv will run a smaller prop at higher revs So does that mean that both will give the same thrust ?? Which is the better choice Cheers

Frank B Members Profile Send Private Message Find Members Posts Add to Buddy List Platinum (DK) USERID: 207578 Bargain Addict! Joined: 04/Jun/2012 Online Status: Offline Posts: 29	Quote Reply Posted: 26/Jun/2012 at 12:38am
	In general you will need a slow motor/large prop for a slow flying plane with a lot of drag. A fast motor/small prop is for speedy jet models. On 3 lipo cells, a good 900kv motor will typically draw around 15A with a 10x6 prop, which seems okay for your standard park flyer. A 1700kv motor will draw around 15A with a 6x5 prop, and in my opinion that belongs on a jet of some sorts. It seems perfect for a zagi-like flying wing. If you compare the thrust and pitch speed of the two setups, you get the following: 900kv motor - 10x6 prop: Static thrust: 864g Pitch speed: 49,2mph 1700kv motor - 6x5 prop: Static thrust: 476g Pitch speed: 83,8mph The first one is able to pull with almost twice the power, and the second one can fly almost twice as fast, so it really depends on the type of plane. I hope this was of any help.

steverb Members Profile Send Private Message Find Members Posts Add to Buddy List Platinum (NZ) USERID: 280280 Newbie Joined: 01/Nov/2009 Online Status: Offline Posts: 17	Quote Reply Posted: 26/Jun/2012 at 2:07pm
	Perfect, thanks for the reply.

Keeth Members Profile Send Private Message Find Members Posts Add to Buddy List Platinum (AU) USERID: 763654 Hobbyking Addict Joined: 20/Jul/2011 Location: Kickatinalong Online Status: Offline Posts: 679	Quote Reply Posted: 26/Jun/2012 at 6:47pm
	Also a lower kv motor will react faster to ESC signals... Makes them better for multicopters where the motors are the only thing that keeps them flying