ESC initialazation problem in cold temperatures

[RFH]

Hi,

I have recently built a big hexacopter. Based on software from Mikrokopter. I run the Flight ME 2,1, hexa dist board with BL-ctrl 2.0.

The hexa is running good indoors and in summer temperatures. But as soon as the temperature is dropping or if its moisture outside I ALWAYS have problems with the ESC initialazation. I start to get problems around 10 Celsius (50 Fahrenheit)-

When I start the hexa. All ESCs are beeping like they should, telling me that they are ready for take of with green leds shining. When I try to start the motors there is always one motor that just wont start and start blinking RED...

The thing is that this problem has moved around. First motor #2 was the problem, now its #4 giving me the same RED LED.

I've tried to change the motors, does not help. Only thing that helps is to bring the hexa inside then everything runs smooth again!

Does anyone have a idea on what could be the problem?

Thanks!

 

[roycruse]

Could be the batteries not having enough current in the cold temperatures so your getting a low battery cut off.

 

[RFH]

Hmm, I've tried 10 different batteries. Warm and fresh batteries. It doesn't seems to be the problem.

Also, once all motors are started they don't stop during flight.

 

[Chris Moon]

Just a thought... Some gyros have some problems initializing in an abrupt temperature change (For instance, going from inside to outside). Maybe on the initialization process the signal to the esc's is a little off? Maybe give it 5-10 minutes for the components to stablize to ambient temp?

 

[ovdt]

What about using silicon conformal coating spray on to the electronics?

 

[Bartman]

i'm dealing with the same problem at the moment. the #3 BL on my XY-8 project worked for one successful test flight and now it's not spinning up with the others. it initializes, even runs with the MKTool motortest function but it won't spin up with the other motors. I changed motor wires with the #2 BL and the motors are fine.
I'll test the temperature theory by letting it sit outside for a little bit and then try again.
Bart

 

[Bartman]

very whacky but I let it sit outside for a few minutes and now it works perfectly. outside air temp is 53 and it's probably 65 in the house with the heat off.
thanks for the temperature suggestions

 

[RFH]

Thanks for the advice guys.

But, I've tried letting the hexa be outside for a looong time, nothing works. The colder it gets the worse everything gets.

In fact. I can be out shooting and everything is fine, then when the temperature slowly drops during the day its just wont work. And thats a loooong "temperature fade"

Maybe I should try resoldering everything.. ouuueaahhhhh!!

 

[Bartman]

rfh
try inspecting your power board with a very high powered magnifying glass so you can see all the little components up close.....sometimes these gremlins we experience can be caused by a tiny blob of solder or splinter of metal. MobasaFlash had a tiny blob on a gyro and it was causing his copter to fly erratically and crash unexpectedly.
good luck with it.
bart

 

[Tahoe Ed]

I have flown several of my machines at 6F including my MK with no problems. I did have a 330mm DIY quad with an FY90Q on it that would not arm unless I armed it inside the house and then took it out to fly. Flight times at those temps is pretty short.

 

[RFH]

Today I sprayed the ESC that seems to have problems with initializing with some plastik-70 electronic spray.

Did some test flights tonight. Whet ground and pretty cold, no problems with initializing so far... I'll report back after some more flights

Thanks for your thoughts!