Hoverfly strange power loss

[Cloud Level Media]

Hello Fourm

I am down in argentina shooting
a winter spot for polartech clothing. I am flying in the with my new Hex setup.
I have been experiencing a few things down here in the cold that I never did
with my octo machine. I have been having a hard time initilazing the board when
it is cold. It takes about 10 or so minuts with the power pluged in to get the
board to initilaze. This might be a cold ESC issue i am guessing. Any thoughts?
More importantly I was flying yesterday first filight of the day and about 3
minutes into the flight I fully lost power. It felt to me like I was flying on a
dead lipo since the heli was dropping as I gave it more throttle. This ultimatly
ended in a hard landing insanly lucky in nature. If I was 1 foot furlther away
from my self when she dropped the copter might have been a total loss. My only
guess is that my batterys were too cold? I kep them in my pack then on my person
for a bit before the flight but I had 15.5 volts left after the crash. This AM I
too the same battery (Warm) and flew for about 2-3 more minutes no problems. I
tried to upload the flight log but the fourm won't let me. Any way to tell from
there what the issue was?


System
latest Firmware

Hex

HFP
AXI 2826/12
turnighy 60 amp esc
5000 25c turnigy
lipo.

Thank you so much for any info

Mike
Cloud Level Media



UPDATE........

Update...

Went up to the new location for
the last 2 days and the Issue began again. When the heli is cold it does not
want to arm. I can leave it pluged in for a while and keep trying to arm it.
Eventualy It will arm with some time. I take off and fly. Flies pretty good for
about 2 minutes max. Then it starts dropping. FAST. I did notice that the green
LED light starts to flicker and sputter on the board while in flight. This can't
be good but I am not sure what the issue is. When the heli is warm like today
when the sun was out it flies like a dream. This is a new machine for me with
about 60 really solid flights on it. (WARM TEMPS )but I have flown my Octo at
temps as low as 5 degres F without any issues. I have now ruled out any battery
issue as my packs are good to go and i have been keeping them body heat warm. I
am now moving to ESC or FC troubleshooting. Has anyone flown 4.0 and up in
really cold temps? Could the new temp calibration have anything to do with the
cold affecting the sensors? Even with the heli troubles I think the shoot went
well. I got great shots in 3 of 3 locations I just missed some really great
opportunities witht the higher eleveation shots. I was just kicking myself
yesterday since it was sunnny without a breath of wind in the southern Andes and
the only thing flying were the condors.



Thanks for any
insight!
Cheers
Huck Norris

Hex
HFP
Axi 2826/12
Turnigy 60
ESC
dx8
turnigy 5k 4s
14' apc

 

[RotorFilms]

Hi,

How new are your Turnigy Li-po's? I'm assuming they are Nano-techs. Were you flying with 1 single pack at a time 5000mah only as I was out yesterday not too cold here and I had exactly the same problem after about 3min's of flying the copter just started falling out of the sky no matter how much throttle input I gave.

My setup is almost identical to yours:
Cinestar hex
HFP
AXI 2814/22
Turnigy 40 ESC
14" APC's

I bought my batteries recently, I would say in the last three weeks and I think it might be them.

Well I'd like to find out what the problem is as well, so if anybody knows anything about this it would be very helpfull.

Regards,

Andre

 

[StormRU]

hm.... i experienced this a couple of times as well. it is strange..... turnigy as well
can it be something wrong with HFP firmware?

 

[Cloud Level Media]

I have the regular blue 25c turnigy 5.0 lipos. They are pretty new. I flew once it warmed up and she flies fine. It is a cold issue for sure.
ESC's or FC board.

For some reason I can't DL my flight log. Is anyone else unable to do so?


cheers
Cloud Level Media.

 

[jes1111]

You say that your octo never had this problem, so I'd be cataloguing the differences - mechanical, electronic, etc. - to identify possible culprits. Electronics can't work at too low temperatures any more than they can at too high temperatures. Two or three minutes into the flight something is being cooled below the point at which it wants to play ball. Presuming you're mostly hovering or moving relatively slowly, the "wind chill factor" that's doing the damage may be coming from your own props. Doesn't sound like the ESCs, since the power loss is uniform across all of them. That uniform loss of power also doesn't sound like a likely symptom of the FC getting cold - it's "running" throughout, and the only connection between it and the ESCs is PWM signals going down some wires - which is still happening, otherwise you'd get a total shutdown. Same with the motors - it's massively unlikely they'd all exhibit the same symptom completely evenly. Which would leave the batteries or the common part of the connection(s) between them and the ESCs. But you're confident that the batteries are not the problem and you (presumably) used the same type on the octo in similar temperatures. Which would leave whatever is between them and the point where the power branches to the ESCs as the culprit. (Although I'd still suspect the batteries - are they in the same position, i.e. subject to the same temperatures, as they were on the octo?)

 

[Bartman]

Mike,

I had a very similar problem and Al diagnosed it as a faulty ESC. About four minutes into a flight I'd begin to see a loss of stability and then it would start coming down. Adding power wouldn't stop it. I could land and then take off again but it would do it again a minute later. The 30A Turnigy Plush ESC's were too hot to touch so it appears one was failing as it got too hot. Changing out my ESC's to 40A Turnigy Plush seems to have solved the problem.

If there's a problem with things getting too cool I'd have to ask if the ESC's and electronics are under a hood. If not you may want to put a cover over the stack and ESC's to keep the heat in and to help them reach a higher operating temperature earlier in the flight.

Hope that helps,
Bart

 

[Cloud Level Media]

after thinking about this long and hard I have only come up with a few ideas. I am starting to think that it is not the board. When I was on site in the cold I put 2 hand warmers directly on the board for a while then tried to arm it. No dice. The board still would not arm in the cold with the ouside heat source. One thing I have been thinking about is at least 3 or so time my RX would not go solid as it does right off the bat when I power up the board. I would restart my radio and power on and off the board a few times then it would go solid. DX8 and 8ch spectrum RX. Also Not sure what would explain the flickering green LED on the HFP just before power loss. Could loss of RX signal do this? I have my board hard wired into the main power harness. I also have a external BEC that I use to power other equipment. I tried that BEC as well with the same results after I noticed the flickering. I have all of my ESC power leads heat shrinked except one. Dang just spitballing! Since I got back from the cold I have flown about 6 packs with perfect performance. I might have to wait untill it gets cold here to really figure this out.

Thanks for any insights


cheers
HuckNorris
CLM

 

[yeehaanow]

What were the temps outside when you had the issues?

 

[Cloud Level Media]

Not too cold. 20-30 F I have flown my octo down to 5 F with no issues.

 

[yeehaanow]

Could it simply be a drift in your endpoints from your Tx/ Rx? Maybe try increasing the rudder EPA on each side a little.

 

[Cloud Level Media]

I could try this in the cold. Unfortunately once it is armed in the cold I am mostly worried about the rig falling out of the sky. It has to be the flickering LED. What would cause that only in cold temps?

cheers
Mike