2 motors heating up ???

[AlienNet]

Hi, i have a H680 Quad, setup is as follows: x4 NTM 2830 800KV Motors, x4 30a ESCs (latest simon k sw) Naza M Lite, Spektrum ar8000, Running 4S 14 Volt, Props are 9 x 3.8, The Quad flies great, nice & stable and can fly for 13 mins, but after 5-7 mins the 2 CW Motors are stone cold, but the 2 which are turning CCW are Hot ??? why can this be when the same load is on all 4 motors, all components are as new with only about 40 mins use. any thoughts or suggestions would be appreciated.

 

[jes1111]

It is likely to be because of an imbalance or "skew" in the rig. The quad is trying to yaw in one direction (CW) and the two motors that oppose that yaw are having to do extra work in order to oppose it. Make sure everything is straight, balanced, level and tight.

 

[AlienNet]

Thanks for the reply jes1111, everything does look ok and setup on the naza assistant seems fine, what you are saying does seem to make sense, is there any one thing in particular that might cause this type of imbalance ?

 

[jes1111]

Well, usual culprit would be motors not mounted dead upright on tubular arms - but if you could post a pic of your rig somebody might spot a clue.

 

[AlienNet]

Well it does have tubular arms, and although they were predrilled on the frame side, the motor mounts could be a degree or two off at the prop end ? i will get the little spirit level out and start from the bench through main frame & motor mounts, then i will try and upload a picture, and let you know how i get on, Thanks again.

 

[AlienNet]

Jes1111, you are a Star, a little bit of fine tuning at the motor mounts as you said, and now all 4 motors are just mildly warm after 12 mins flight, i guess there had been a little bit of skew and 2 motors were constantly fighting against it, Many Thanks for your help, it is very much appreciated.

 

[PeteDee]

Well for starers I think you are a little under propped with 9 inch props, I have used 9x4.7's on these motors and they never gave any grief like overheating, the earlier version of these motors didn't like 4S, although I see the new version is supposedly rated up to 6S, have you tried 3S to see if it still overheats? Which version do you have?

Secondly the NTM motors can be pretty hit and miss, you may have a couple of duds, try swapping positions of the motors, see if the problem moves.

You could try a non SK firmware, what actual ESC's are you using? Try swapping the ESC's as well.

What is your AUW?

Cheers

Pete

 

[AlienNet]

Hi,Pete, as stated above the problem now seems to be cured, the motors are the new Ver: i think that i will try a set of 10 x 4.5 props tomorrow and see how they perform,

Cheers:

 

[PeteDee]

According to specs they should be able to do 11-12 inch props.