Hello, So I am off to outer Mongolia on the 2nd Jan with our cinestar 8. I have been told there may be temperature highs of -18C! (0F) with lows of -40C at times!! Yes, I know I have my work cut out! Obviously I will only fly at the warmest times of day but we are living with a nomadic tribe so the whole process, assembling, charging batteries, flight pepping will be done in cold conditions. Anyone got any advice on flying/ operating in cold conditions? Batteries are an obvious issue. I think I ill replace the plastic tube clamps with aluminium ones, not sure how my wooden xoar props will react.. will spray them with de-icer. Flying with wookong and converted brushless gimbal so not sure how silicone chips will react. Any advice or tips and tricks would be gratefully received! Laurence
I wouldn’t bother with de-icer, IMHO. If you’re in icing conditions, you’re going to have worse problems. Batteries and their performance are going to be the biggest issue. There’s a thread here where many battery issues such as operating in Very Cold Climates is discussed. http://forum.freeflysystems.com/index.php?threads/voltage-16-8-to-14-in-30-sec-flat.2505 From my cursory read of this thread and my understanding of the issue of ambient temperature, you may be in for an unpleasant experience in the kind of temperatures you’re describing.
Try putting props and batteries in your freezer and simulating their behaviour, Laurence. If you are at -40 (and that happens to be the same in F and C), I suspect the humidity will be so low that you will not be in natural icing conditions. You may induce them if you take the equipment from indoors to outdoors and have freezing condensation forming -- so you may have to "cold soak" the kit to prevent that. Have you sprayed the MK electronics with conformal acrylic spray -- specifically the power distribution board (presuming you have MK electronics)? Andy.
A clear plastic dome placed over the hub can help the electronics to retain their internal temperature several degrees above ambient. DJI WKM specs state a minimum of -5 deg C for the electronics. Other flyers here in Canada state that it is more critical to allow the MR to sit outdoors for about 15 minutes before flight because MR temperature stabilization is most important. But batteries can remain inside your vehicle or house until ready to connect. Some here have flown MRs at -14 deg C without incident. I find it too painful and lose all interest when it gets below -10 deg C. A special RC xmitter mit can be put over your RC xmitter so you can retain tactile senses while keeping hands and the RC xmitter electronics and battery warm. I was about to test fly my new Cinestar 8 c/w DJI A2 today but we just had a major blizzard.... stuck in my man cave for the long spell now I guess.
I've flown in sub-zero temperatures quite a bit with no serious problems. Your batteries will generate heat as they discharge, so if you can start with them reasonably warm and wrap them with some type of insulation you should be fine. I've started with pretty cold batteries and you can actually see the voltage rise via telemetry as the batteries generate heat while flying. I heat water bottles and put them in a small cooler with my batteries. The board should be fine. One issue I've had is that cables that are flexible at normal temps become very inflexible when cold and that gimbals to fail, so think through your cables carefully. Generally, I was shocked at how well everything worked. Probably best to fly conservatively though.
The problems of going from cold to warm are rare. Just plan on giving everything some time to warm up and any condensation will evaporate. Going from warm to cold is not a problem as there's no condensation there.
I flew around -20 celcius degrees. The biggest issue were the batteries. I sprayed the electronic with conformal spray and they were not affected by water drops created by the temp changes. If I fly again at cold temperatures; I will put batteries into a big thermo bag full of hand warmers if I cant keep the batteries in a warm place until I fly.
lots of great advice so far! bought some conformal spray, bought a plastic dome, bought a transmitter mitt, bought a thermal battery carry bag and over a thousand chemical hand warmers.. I kid you not! (its a long shoot) just spoken to xoar and they say the wooden props will not be affected. (although i do notice they shrink and expand at varying temps and humidity! shane, when you say the gimbals fail, what do you mean by that? I am running a converted brushless cinestar gimbal with alexmos controller.
It just happens to be extremely cold in Wyoming at the moment, so plenty of opportunity to test. My car thermometer bottoms out at -22F and it was pegged until about noon yesterday where I was flying. I do not use any spray, I do not worry about taking the entire helicopter in or out of a heated car or house. I keep the batteries warm until just before flight and wrap them in thin layer of bubble wrap. I get the same flight times as in warmer weather and the batteries are warm after the flight. The only problems I had yesterday were with trim and I'm not sure what's causing it because the drift was in different directions on different flights. I'm not sure if it's a motor issue, an ESC issue, or something with the flight control board. It was not a big problem. The gimbal doesn't actually fail, but I run fpv off my camera and the wire to the transmitter mounted to the frame becomes inflexible in the cold, and just this cable not flexing can cause the low-torque gimbal to flop over. It's easy enough to solve. Below about -20 it is easy to snap brittle cables, so try to find ways that they won't need to bend. I'd recommend new batteries for everything and a spare for your radio. My hover changes from -6% in warm weather to +4% in cold, so I reset my failsafes to get a softer landing if needed. I'd also recommend modifying gloves to allow the inside of your fingers to just touch the sticks. I've found wool is best because it doesn't become too stiff in the cold. The fingerless gloves are not warm enough for me. I've tried the rubber coated work gloves, but they become very stiff in the cold. Good luck!
There are these: http://www.bhphotovideo.com/c/product/812014-REG/Freehands_41011MM_Men_s_Leather_Gloves_Medium.html I put one of these pads, http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias=sporting&field-keywords=hothands , on the back of my hand and insert hand and hot pad into the glove. The Hothands brand stays hot for far longer than most others, in my experience. Andy.