Motor questions

[xMeox]

Hi there!
Im currently building a FT 3d. I havnt flown her yet but Im pretty sure that my NTM 28-26 1200kv has a little bit too less power. Now Im thinking about another motor option, but I cant decide which one.

Im tending to the 35-36 1800kv (it did great in the speed challenge) thought Im not sure if it also is a good option for 3d flight. In addition, can anyone explain me why there are different "versions" of the same motor, whith different kv numbers? why would I go for one with lower kv?

Any help is very appreciated

regards, xMeox

 

[brettp2004]

I flew my FT3D with the NTM 28-26 1200kv and it flew great. I think I ran a 9x6 or 9x7.5 prop on it. I would try it before you bought a new motor, I think you'll be happy with it. As far as the different versions of motors I'm not sure exactly what motors your talking about. If it's just a different KV then usually a lower KV motor will be able to swing a larger prop which gives you more torque but less speed. I'm not an expert in this area so someone else might be able to provide some technical details but thats the way I understand it.

 

[earthsciteach]

The same size motor can have different performance based on the number of windings on the stators. As brettp2004 said above, a lower KV motor can swing a larger prop allowing for more torque. In general, the same motor at a lower kv can pull a heavier airplane at slower top speed. At least, that's how I see it.

 

[brettp2004]

Does the number of windings dictate the KV?

 

[earthsciteach]

For a given bell size and stator number, yes.

 

[xMeox]

thanks for the fast replies!

I have installed an 8x6 prop and an 3s battery right now. Im pretty sure, that I cant hover with this combination.
Did you used a 4 or 3s battery in yours brettp2004?

Thanks for the clarification earthsciteach. In addition, I ordered a watt meter to be able to check which prop gives the best result for my motors. Should I try to get as near to the max Watt numbers listed on HK, or are these numbers a dead line, which I should never cross?

 

[brettp2004]

Ya I used a 3s. The watts listed on hk are the max power the motors will pull. They won't pull more than that, but if you put too big of a prop on there you can burn them up.

 

[jayz 84]

XMeox dont use the 35 36 1800kv that motor is good just for speed. I have one. You really want a lower kv motor which = bigger prop more thrust but also look at you watts the higher the watt the more power shell provide. When i built one i used th turnigy d 3530 1100kv with 1500 3s with a 10x4 to a 11x4 looking at 1200 to1700g of thrust putting you at half or alittle les throttle to hover

 

[xMeox]

Thanks for the answer! that really helped me a lot! I do have some 10x4.5 props here, would this work with this motor or is it too much?

 

[jayz 84]

Thanks for the answer! that really helped me a lot! I do have some 10x4.5 props here, would this work with this motor or is it too much?

You might get away with that 10x4.5 just watch your full throttle. Take it out run it full throttle a few time while the motor is being flight cooled. Bring it down and check the temps on all your electronics

 

[xMeox]

Update:
I ordered the turnigy d 3530 1100kv and tested it with different sized propellers. With a 10x5E ACP Style propeller and 3S batteries I didnt get even near the upper limits of this motor. With a 11x4.5 Slow Flyer Prop I reached 24A and about 260W, which is also far away of the 330 in the description.

 

[jayz 84]

Update:
I ordered the turnigy d 3530 1100kv and tested it with different sized propellers. With a 10x5E ACP Style propeller and 3S batteries I didnt get even near the upper limits of this motor. With a 11x4.5 Slow Flyer Prop I reached 24A and about 260W, which is also far away of the 330 in the description.

I have run 11x7 apc on it with no prob. Not sure of the watt tho its been awhile sence ive used that motor

 

[quorneng]

xMeox
The 3530 is a 4 cell capable motor. I bet you would get to 330W with a 10x5 on a 4S.
The question really is how much power do you need. If 260W is sufficient then use it. Everything will stay that bit cooler.

 

[jpowers]

I have a pusher set up and every time I fly it the prop comes loose should I use lock tight?

 

[jayz 84]

I have a pusher set up and every time I fly it the prop comes loose should I use lock tight?

You could but its gonna suck to get it apart. Make sure you hold the prop and motor tight in your hand then really tighten that nut down. Ive had tons of flights on that motor and never had the prop come loose

 

[jpowers]

If I hold the motor it just spins on the shaft but I can't hold the shaft tightly with needle nose pliers. I am going to try different spacers.