Motor / ESC Screeching or high pitch whine

[Bexcopter]

Hi,

I have been configuring a new aerial video platform and have come across a screech or whine.

It appears to come from either the motors or esc and from more than one but its hard to tell.

You can hear the sound in the video:
https://www.dropbox.com/s/1g7ic86wrmtnsps/2015-03-20 18.42.53.mov?dl=0

Does anybody know what this is?

I am assuming is the esc timing or similar but im not too sure?

4 cell 16000mah lipo's
13x5.5 props
Afro 30amp esc (NFET)
SunnySky v3508-20 580kv
Naza-M V2

Thanks
Bexcopter

 

[Pumpkinguy]

It sounds tinny. Like a mechanical sound. A piece of aluminum vibrating.

 

[Bexcopter]

Hmm, possibly.

I have never come across this before which is why im struggling to figure it out.

I will try and do a couple of tests but it definitely seems to be localised to the motors from what i can tell,
and im still unsure how many are doing it or whether it is just something vibrating.

 

[Palin]

Did you solve this Bexacopter? I have the same problem with u7 motors and flame 80a escs on a 6s.

 

[Pumpkinguy]

Andrew already told you that the flame 80 is the not correct esc for the u7. You cannot use the flame 80 with that motor.

 

[Bexcopter]

Did you solve this Bexacopter? I have the same problem with u7 motors and flame 80a escs on a 6s.

Yeah sorry for not posting. It turned out to be a loose screw in one of the arm clamps that was vibrating.

 

[Palin]

I know he did, however, I need to know from Tmotors, and they haven't replied to my query yet. All I've seen online is every reseller stating "Flame Pro 80A can also be used with U7 Power series motors on 6s only."

My skyjib was specced up by Multirotorcraft with the u7 motors and the Flame 80A escs, and I need to see a definitive answer before I spend hours ripp

 

[Palin]

Thanks Bex. It's amazing how many issues can cause very similar symptoms.

 

[Mojave]

Palin - I tried to get an answer from T-motor awhile ago. They never responded to me. I trusted Andrew, but he did design my system. Here is what the U7 sounds like with with the T80A (they were new at the time and Andrew got these ESCs before they were released to the mass market):

Here is my old post: http://www.multirotorforums.com/thr...r-t80a-400hz-compatibility.17980/#post-165764

Good luck with your build!

 

[Palin]

Thanks Mojave! Your T80A's sound much nicer. T Motors have just responded. Evasively. They said to bench test them together. Not a great answer. I've asked them again as I really don't want to spend hours rebuilding.

 

[Fadi]

I want to mention some information about u7 420kv and Flmae 80a ESC , i went to one of the distributors shop and he showed me the catalog from T-Motor and it is written that for U7 motor the ESC recommended for it is [T80a and Flame 80a], so Flame 80a is recommended for U7 and these information from T-Motor. I tried these comb. and it is working good.